The Journal of the TEXTILE INSTITUTE Official Journal for Communications (Transactions) released fpr Publication by the British Cotton Industry Research Association (including its Rayon and Silk Sections), the Wool Industries Research Association the Linen Industry Research Association and the Technological Laboratory of the Indian Central Cotton Committee

CONTENTS PROCEEDINGS SECTION Lancashire Section—The Past, Present and Future of Cotton Spinning Machinery— Sitigton ...... P13-P23 Reviews ...... P24-P25 Notes and Announcements—-Additions ' to the Library; Annual General Meeting: Mather Lecture: Election of Officers, 1945: Examinations, 1945; Vacancies; Diplomas; Institute M em bership; Obituary ...... P25-P27 Institute Meetings ...... P28 STANDARDISATION SECTION Testing Cloths for Tensile Strength—Practical Details in Testing Cloths for Tensile Strength— The Staff of the. Testing Dept., Shirley Institute, B.C.I.R.A...... S1-S14 TRANSACTIONS SECTION 3—The Optimum Conditions for Setting Strained Animal Fibres — Hind and Speakman ...... T19-T34 ABSTRACTS SEC T IO N ...... A53-A92

STANDARDISATION ISSUE

THE TEXTILE INSTITUTE ST. MARY’S PARSONAGE, MANCHESTER TELEPHONE BLAc.KFRIA.RS 2016

FEBRUARY 1945

THE JOURNAL OF THE TEXTILE INSTITUTE

Vol. XXXVI FEBRUARY 1945 No. 2

Lancashire Section THE PAST, PRESENT AND FUTURE OF COTTON SPINNING MACHINERY

By G. H. A. S in g t o n (Paper delivered to the Lancashire Section 2$th November 1944)

It might be interesting to you all here this evening were I to touch on what our predecessors did well over one hundred years ago; what we are doing to-day, and what those who come after us may be able to achieve after we have left this mortal coil, in years to come. I therefore propose to divide what I have to say into three categories under the heading of " Yesterday, To-day and To-morrow.” It is easier to speak of the past and present than it is of the future for I do not pretend to be a clairvoyant and I like to hope that the reason for such a very large number being present here to-day is in no way due to any feeling you may have that I may be about to predict what the future will bring to us in the way of new machines, new processes and new ideas. Beginning with yesterday, I have collected from the original machines used in the cotton spinning industry in the days of Crompton, Arkwright, Har­ greaves, and others, various parts of their machines and, Gentlemen, I can assure you these are the actual parts themselves, and have alongside them placed the same parts as taade by the present-day textile machinery makers. After this talk is finished, I would invite you all to come and look at these various parts and you will see—an extraordinary resemblance between the flyers of to-day and as they were then, for in those days ring spinning was unknown. There is precious little difference too between the fluted rollers of that time and of to-day; the weights themselves bear a striking resemblance to each other; the top rollers with their leather covering untouched since they were put on two centuries back are identical with the solid top rollers on to-day’s machines. I think, in general, one may say that the actual spinning at that time was very much the same in principle as the spinning is to-day, at least the system then adopted has undergone little change in this respect. So far as the drawing is concerned the system of having rollers running at different speeds, particularly in the drawing frame and on the spinning frame, is the same. It is true that Proceedings on the drawing frame there was no system of Ermens’ clearers, but there was a top clearer and that I have brought with me. Reverting to the carding, the cylinders were of wood and had only a diameter of 36 in. and a doffer a diameter of 14 in. The system of flats had already come into being, these being 9 to 12 in number and carried in a stationary position in the card, I have brought with me one of these wooden flats clothed with the actual card clothing of those days. I have also brought a modem flat clothed with the fillet clipped on, as we all know it. As to machinery before the carding such terms as hoppers, openers, Crigh- tons and scutchers were unknown, all they then used was a wooden machine which was called a “ lap maker.” This was of a “ Heath Robinson ” type, con­ sisting of a long wooden table on which the cotton was placed by hand, being manually opened while doing so. The cotton passed between a pair of calender rollers and was rolled into a lap on a wooden lap roller. One method of preparing rovings was by the use of the lantern frame which coiled drawn material into a container in the shape of a lantern, similar in principle to what is now obtained by a depositing coiler. Mule spinning was introduced in 1767, two years before Arkwright’s Water Frame. It had a stationary carriage and a movable creel, the whole being worked by hand. A large diameter wheel turned by the operatives was employed to turn the spindles, and the creel was traversed backwards and forwards by the operative by hand to perform the drawing operation. When the desired length of draw had been obtained, the operative would secure the rovings by hand pressure on a long rod which trapped the rovings and prevented further delivery, and the operation of final twisting was carried out in this position. Still turning the large hand wheel and driving the spindles, the creel was traversed to its forward position near the spindles and the process of winding was done at the same time. This meant that the two hands were actually operating four things at the same tim e: — (а) Driving the spindles, (б) Traversing the creel, (c) Nipping the rovings, (d) Controlling the faller for winding on the cop, all with two hands, and that so far as history relates was all the operatives possessed at that time, although they certainly needed four. It is from this stock that the expert craftsmen of Lancashire have sprung. These mules contained only about 50 spindles per machine. The flyer spinning frame, known as the water frame, was introduced in 1769. Incidentally the name water frame was given because it was driven by water power. Most of the parts displayed are taken from this frame which was manufactured by Arkwright. Perhaps, however, the greatest change in principle that has taken place is in the machinery before carding; many machines, as you know, have been introduced which were unknown in Arkwright’s days, and the methods of cleaning and opening of cotton have changed radically since those days. I shall speak of this later. And now as to to-day. W hat is happening in improvements, modifications and gadgets to increase production and improve the quality of the yarn spun ? I have read through two papers which I wrote in 1931 an d 1938, and I find they con­ tain a great deal of matter which is completely up-to-date to-day. In fact, I find that I can add very little to what I said then as to “ Novelties in Cotton S pin n in g .” The increasing importance of opening combined with cleaning has been more than ever confirmed during recent years. Lancashire Section

The number of cleaning points, by which is meant the number of times the cotton is beaten from the moment it leaves the bale until it becomes a lap ready for the card, depends very largely upon the particular type of cotton used. But even that cannot be said to determine definitely the number of cleaning points necessary, because each season would seem to bring forth a slightly different condition in each particular type of cotton baled. Speaking generally, however, I think one may say it has been found that, given a sufficient open­ ing prior to the first cleaning or beating point, the following is what should be adopted: — No. of cleaning points 7 ... Indian—low Bengal of very short staple and dirty. No. of cleaning points 6 ... Low Middling American, say £ in. to f in. No. of cleaning points 5 ... Good Middling American, say $ in. to 1J in. No. of cleaning points 4 ... American and Uppers Egyptian, say 1Jin.to ijin. No. of cleaning points 3 ... Sakel—ij in. to in. The use of striker cylinders as against 3-bladed or 2-bladed beaters would seem to be advisable throughout, as being less liable to damage the actual staple itself, because the number of revolutions per minute of a 2-bladed beater must be greater than the number of revolutions per minute of a 3-bladed beater, in order to obtain the same number of beats, and this means that the force of the blow is greater and more liable to damage the fibre. However, at the final beating point, especially so far as Indian and low middling cotton are con­ cerned, a 3-bladed beater seems to be still the more popular for a finisher lap. A reason for such preference is the fact that the finished lap for the card has a more compact appearance, i.e. is less lofty and therefore less bulky for carry­ ing, and less inclined to “ flake off ” during transport, though against that is the fact that the more closely compressed the lap, the less easy it is for the card to do its work. The use of cages such as the Shirley, the patent condenser and dust cages following beaters, for the elimination of dust and dirt are being more and more applied everywhere. These have been particularly successful when applied, and the card room is most certainly less prone to become dust laden during the carding process. The extra number of fans and cages used, and in some cases the added size of them, has necessitated an increase in space for exhausting the dust and dirt. In certain instances, existing dust cellars are not large enough to carry out the additional work required, and in others, where, say, a new mill has been erected on ground which does not allow for underground cellars, it has been found necessary to evolve some scheme for blowing the dust and dirt elsewhere than underground. Dust filter bags have been employed, and have in many cases proved very successful, but as an alternative to a dust cellar or chamber, they should only be used in dire necessity, for they have to be kept clean and to be emptied periodically, all of which entails extra labour. Many minor improvements have been applied to carding engines, but the most notable is perhaps the large diameter can which is particularly suited for coarse and medium counts. I am not going to touch on the double coiler, i.e. splitting the web at the dofler and feeding two cans, because this is only suit­ able in exceptional cases, and is most economical on very coarse work. Modern combing equipment, including the new model Nasmith comber is, of course, well known to all of you, and I don’t think I need say very much about it except that not only is it the finest machine obtainable for combing cotton, but it can be said, I think, to be the most perfectly made textile machine constructed anywhere, and you in Bolton should be proud that you are its greatest users. In passing, I cannot help referring to the recent death of my very old friend, Mr. J. W. Nasmith, whose name will live throughout the world wherever combing of cotton is carried out. P l 6 Proceedings

The elimination of one or even two passages of flyer frames has been a very prevalent practice during the last few years; in fact, the high draft introduced on these machines has been perhaps the most revolutionary step taken in spin­ ning mills during the period in question. On the continent of America, par­ ticularly, the system has been adopted very largely indeed. It has spread in some cases to other parts of the world and has been found, given the same conditions as the older and original method of drafting in preparation machinery, to be almost equal and in some cases equal in strength, regularity and appearance to the yarn by the older methods produced. I have seen—and I am speaking without any exaggeration—a very large number of tests on all types of cotton, with the result that in the end it is very difficult indeed to lay down the law and say definitely: "Y ou will get a better yarn under good conditions, or even that you will get as good a yarn under bad conditions.” Yet, notwithstanding this, many firms have adopted the system and some contend that it is as good as others, that it is better than with two or even three passages of speeds. In spite of all I have said I must frankly admit that very careful strength tests have been taken time after time and it has been found .... speaking in a general sense .... that the old-fashioned three lines of drawing, three lines of speeds will give you 5 per cent, to 6 per cent, stronger yarn than that produced from rovings made on the new lap doubler and high draft speed frame. At the same time, however, a perfectly commercial yarn can be produced on the short cut system. • Experience has shown that the hank of the sliver or roving and the yarn to be spun are not the only important factors, but that the length of the staple and even the “ denier ” of the fibre has got to be taken into consideration. Most people in the cotton spinning industry think generally in terms of length of staple when determining what cotton to use for certain counts, but my friend, Dr. Balls, who for many years has been the Principal at the Egyptian Government Research Station in Cairo, contends that the main factor in choosing the type of cotton suitable for certain counts and types of counts, is the “ denier ” of the staple and not altogether its length. Then again, some cottons are of a hairy, and therefore of a clinging nature, whereas others are devoid of this particular attribute. One factor making for smooth and even attenuation at high drafts on single passage speed frames is the fact that an untwisted sliver is being dealt with. It is, of course, the fact that a twisted roving fed to the intermediate or roving frame that imposes strict limits to the high drafting that can be employed on these machines. General experience has shown over a number of experiments made that the results may be summed up as follows: — " W hat is one man’s meat is another man’s poison.” A spinner who has a weaving shed which uses up all his yarn, may be con­ tent with a yarn of not quite such high quality as his confrere who has to sell his yam on the open market. Many gadgets have been tried in the last few years on high draft flyer frames. In order to get less piecings 12 in. cans have been employed, and although this means that the cans project a considerable distance from the back of the frame, the disadvantage has been partly eliminated by various forms of assisting rollers and suitable passage room between the cans. The system of using a lap former, too, for making measured laps direct from card cans and using these to feed a lap drawing frame has been adopted in many cases. The lap drawing system is increasing in popularity; it possesses many advantages such as the production of complete cans of sliver, free from piecings; it enables high production per operative to be obtained and at the same time, the operatives’ duties are less arduous. There is economy in floor space and definite better working conditions. Lancashire Section

On the high draft speed frame, where obviously cans—be they 9 in. or 12 in. —last a very considerable time, particularly when there is as much as 25 of a draft, the assisting of the sliver from the cans is of considerable importance and various types of assisting rollers have been employed. Creeling is reduced to a minimum and all rovings produced are free from piecings when normal running obtains. Frames are made with four rows of rollers arranged in two zones and with a sliver trumpet on a traverse slide which works in unison with a special condenser form of traverse guide between the second and third rollers. The guide is shaped so as to control the selvedge edges of the sliver by a turn­ over effect reforming the sliver after drafting in the first zone and preventing a jagged selvedge going through to the final drafting zone. It is particularly important, wherever possible, when employing high draft­ ing to open and clean the cotton thoroughly, without damaging the staple, to card lightly and to use a fine hank drawing sliver. I give herewith an example of drafting by one passage of speeds compared with drafting by three passages of speeds. The drafts between the respective lines of rollers are also given: — Single Passage Drafting. Hank. Draft. Drawing Frame •18' 6 0 6 ends up. Single Passage Speed Frame . 5-0 27-8 Three Passages. Hank. Draft. Drawing Frame •18 6-80 6 ends up. Slubbing Frame ... •68 4-53 1 „ „ Interm ediate Frame ... 1-75 5-65 2 „ „ Roving Frame ...... 5-0 5.72 2 „ „ (In both cases to spin 40s from Doable Roving). Drafts between Rollers Single Passage Speed Frame Three Passages of Speed Frames; 3rd and 4th ...... 5-0 Slubbing ... 3rd and 2nd ,. 1.2 2nd and 3rd 1.06 2nd and 1st .. 3-76 1st and 2nd 5-24 Intermediate 3rd and 2nd .. 1-25 2nd and 1st .. 4-5 Roving . 3rd and 2nd .. 1-25 2nd and 1st .. 4-58 High drafting on ring spinning frames is no new feature. It is alm ost exactly 21 years ago, for it was in October, 1923, when in Italy I was able to show one of the largest firms there, who had 200,000 spindles, that high draft ring frames were the only type of ring frame to be ordered, and I booked the order for 32,000 spindles for combed yarn to spin average 60s to 80s for th e Manafacturra Festi Rasini, which machinery was working well in Verona only a few months before the present hostilities started. It is not pleasant to think what will happen to this part of the world when the Allied Forces get further north and have to pass that way, as they will do. Apropos of this you will be somewhat shocked to hear .... at least I think you will be shocked .... I certainly was .... that the manager of a large spinning mill, not 50 miles from where we are all assembled, only at the end of last year when discussing with friends of mine technical points of tex­ tile machinery, particularly referring to mules, which were the only spinning machines which he had in his mill—he was spinning and is spinning to-day 30s to 40s—and when it was pointed out to him that his idea of putting in new mules was completely out-of-date, he made the following remark: " Do you really think rings have come to stay?” Further comment is needless. I am sure the particular gentleman in question is not present this evening, as it is Proceedings evident he does not attend the lectures given under the auspices of the Textile Institute. There are several methods of high drafting, in fact there are hundreds of patents, but from all these have emerged two principle systems, 'first the roller systems employing three or four lines of top and bottom rollers, and secondly, the apron systems employing single or double aprons. These latter have been employed for many years, the double apron system is the well-known Casa- blancas arrangement, and the original single apron system is the Le Blan Roth or Toeniessen system. These have been very successful and curiously enough in some countries one or the other of these systems has, if not exclusively employed, become the favourite form of high draft spinning. If the apron systems are kept clean there is no doubt whatever that they are an asset, par­ ticularly in the case of short staple cottons of varying staple lengths in' helping to convey the fibres from the back roller to the front roller and exercising the necessary control over all fibres in the mixing. Experience has shown, however—and I am merely giving you my own personal experience—that when one comes to fine counts—I am speaking now of 80s and over—the four line roller arrangement is the most popular and con­ siderable success has been achieved in spinning commercially even 150s counts on ring frames. Generally, these yarns are from cottons which have been combed, the percentage of short staple is very low, therefore the same amount of rigid control over varying lengths is not necessary and sufficient control can be obtained by the use of four lines of rollers. Another important development on ring spinning frames is the out-end drive, this facilitates the changing of wheels at the gear end without hindrance from any driving equipment, whether it is by belt, rope or motor. Being fitted with satisfactory stop motions to stop the frames if the doors are open, and to prevent the frame from being started while the doors are open, they provide the necessary safety factor to prevent accidents. The introduction of a plastic wheel in the train of gearing, and all other gear wheels with machine cut teeth, is a factor which assists in reducing noise to a very great extent, if not altogether. It is well to note that the demand for large bobbins on ring frames spun on, say, 8 in. lift, and 2 in. rings, giving a weight of yarn on each package of, say, 4 ozs. of 20s English counts, and saving more than half the number of doffings per week on the normal ring frame, and eliminating the knots in winding, means sacrificing high spindle speeds. It must, however, always be a matter of very careful calculation and consideration up to what point such long lifts and big rings are really an economic proposition, and I should strongly advise spinners seriously to consider the question as to whether the long lift and the large diameter ring should be adopted for counts higher than, say, 28s E nglish (23-71 F rench). Top rollers covered with cork or synthetic material have been extensively used in America in place of leather and woollen roller cloth. This system of roller covering has now begun to be used on this side of the Atlantic. It is well to point out that it is quite impossible to lay down definitely what system of high drafting both in card room and spinning room will suit the individual case, until every fact has been taken into account. For instance, here are a few of the points that need consideration in coming to a conclusion: ( 1) The types of cotton to be used. (2) The class of workpeople employed. (3) Whether the labour is cheap or costly. (4) Climatic conditions. (5) Whether quality or quantity is mainly sought after. Only from the considered experience of an expert can one hope to receive advice of real value. Lancashire Section P 19

In addition to the three fields of development which I have touched upon, there has been an interesting adaptation of the comber to the preparation for medium counts such as 30s and 40s. By the process, which is known as “ semi- combing ” a minimum of waste (5 per cent, or 7 per cent.) is extracted and the resultant yarn is of improved quality and commands a higher price. The word " To-morrow ” is even a greater misnomer than the word “ Yesterday ” was to describe what was being done in those days of long ago, for “ To-morrow ” may mean years and years and years ahead, possibly after all present here to-day, and our children too, are dead and gone, but there will come a time when the treatment of cotton as received from the cotton field to the spun yarn will be done in a lesser number of operations. It may be a com­ plicated machine—it may even be a simple one—none of us can tell, all sorts of efforts have been made, particularly in the last twenty years, to evolve short­ cut processes. I myself some fifteen years ago saw a ring frame working in Germany with 200 of a draft. There is, however, the economical aspect to this development. It is recognised that for high production per machine and low operative cost per pound of yarn the present cotton system provides the cheapest means of producing yarns from fibres of any of the textile industries of the world. There may be different methods actually in use within the cotton industry, but I am speaking now of the industry as a whole. Worsted spinners and flax spinners employ machines which draft and twist in a similar manner to cotton machinery, but never with such a low amount of twist coupled with com­ paratively high speed as obtains in the cotton industry. The cost per pound of yarn in a cotton mill is low, one may say that the total operative cost in the production of a medium count yarn may be <|d. per pound. The most expensive operation is that of the actual spinning, which amounts to about 57 per cent, of the total operative cost. It is here, therefore, that economies should be sought in producing at a cheaper rate. Then, too, a knowledge of psychology and of the mentality of the person or country with whom you are dealing means a very big step towards getting their orders. We in this country do not always understand the psychology and the mentality of those in other countries. I can imagine how disgruntled you would all feel if I left out of my remarks any mention of the recent report of the Cotton Mission to the U.S.A. On the other hand the last thing in the world I wish to do is to offer any criticism on what is a very workmanlike and efficient report. I read it through thoroughly twice over, and so far as we English makers of textile machinery for the spin­ ning of cotton are concerned, I did not find one single derogatory remark about it. There were interesting details given of layout of mills in the U.S.A., and the hours of work, the piece-work prices, costs, etc., but nothing, as I say, which even insinuated that our machinery was not up to the standard of the machinery made by our American competitors. Imagine then my surprise when within a day or two of the report being issued I was stopped in the street, and was tackled in the train, telephoned to. and received letters all asking me what I thought of the accusation that the textile machinists in this country were out of date in their products. It was after this that I decided to read the report over again, which accounts for my having read it twice, but I can find no hint that the machinery made for the spinning of cotton in this country is in any way inferior to that made by our competitors overseas. It is, therefore, not merely a matter of “ Qui s’excuse s’accuse,” because we have nothing to excuse ourselves about. I take my hat off to the mission and every member of it for the work that was done, but if I may speak rather frankly, I think it was a pity that not one single member of the mission, as far as I can discover, ever visited any of the makers of cotton spinning machinery in this country to find out what is P 2 0 Proceedings being done by them, for at any rate ten years or possibly more. That being so, I can hardly think that the mission as a whole could have been cognisant of what new machines and new gadgets on them were being manufactured in this country. At any rate they have been able by visiting the makers of such textile machinery in the U.S.A. to put themselves wise on what the Americans are producing, or intend to produce, and possibly later on I like to hope that we may have the pleasure of showing these gentlemen what has been and is being made by the counterpart of the American makers in this country. I think, too, it is a pity that the mission, which numbered seven, did not include at least one representative of the textile machinery industry. Within a few months of our mission visiting the States, the " powers that be ” over there decided to send a counterpart cotton mission to this country. They numbered five—five hale, hearty and very able gentlemen they were too—but of the five two were the vice-presidents, respectively, of the two largest cotton textile machinery makers in the States, and there are only three of them, who are our competitors over there. Why did the Americans in making up their mission allot nearly half the number of places to their textile machinists, whereas we omitted them altogether? Why? I really don’t know. D o you? None of us know, of course, what the future of cotton spinning will be. It may be that some synthetic filament will be evolved having all the qualities which have enabled the cotton thread to serve mankind so well. In that case, the systems which have held the stage since Lewis Paul first drafted with rollers will be consigned to oblivion. Our machinery will depreciate to zero, and we shall become intensely interested in the ruling price of scrap iron. But the cotton spinner is very adaptable. Even if all the world’s cotton fields are wiped out by mustard gas, and the Dark Ages return, he will surely be found using his card flats and the strikers of his porcupine cylinders to scrape the skins with which he must clothe himself . . . for our machinery can always be brought up-to-date. I feel that much that I have said is useless when I realize the fact that nowadays there is actually a machine which is apparently near to solving the everlasting problem of the possibility of putting a bale behind the machine and spinning direct from it on, let us say, thin paper tubes; thus every home will be considered incomplete without its own spinning plant. But if none of these calamities befall us, it can safely be predicted thft the technique of cotton spinning will evolve yet further, and by research and design continue to make a cotton spinning mill a pleasanter place in which to work, and spinning an increasingly economical process.

DISCUSSION M r. Goddard : In the report on the mission to the U.S.A. it refers to the blending machinery in the U.S.A., and it makes a statement that they have a machine capable of blending 24 bales at once. Could you give me any idea of the form of the machine ? Mr. Sington : The type is a Hopper Blender. There are four, six or eight feeding on to a running lattice. They may have two machines in each series or up to twelve machines in series, thus you can get the blend of 24 in one product. M r. Goddard : But are you getting the blending of 24 bales on the finished lap ? Mr. Buckley : Yes. The material is opened by the blending hoppers and material is blended in its opened form. M r. Goddard : It is not new, is it ? Mr. Sington : No. Mr. Walton : With regard to the U.S. report, which I am pleased to bear you sneak about. I have read ii; through. So far as spinning is concerned, I think that we in this country are more up to date than they. I once heard a gentleman say that he had seen in foreign countries a mill where raw material entered at the top and flowed through to give the finished product at the bottom. I told him that he need not go abroad to see this. We produce here from waste what they cannot produce. Lancashire Section P 2 I

Mr. Singlon : I think that the trouble is that we are not great advertisers. Mr. Birtwistle : Could you tell me more about the lap doubler and feed of laps on to the drawing frame ? Mr. Sington : The measured laps are cut off automatically and therefore, every lap is of the same length and weight when put on a drawing frame. The laps never have a piecing. Mr. Birtwistle : Is the machine like a Derby Doubler ? How many ends are there in one lap ? Mr. Sington : Sixteen ends are wound into each lap. There is no draft. Mr. Birtwistle : Are they drawn out in a whole lap ? What type of draft ? Mr. Sington : The laps are drawn by five lines of rollers with a draft of 16 on the draw frame and the hank sliver delivered is approximately the same as the card hank. Mr. Birtwistle :' If you have 180 on roving frame, what would you get on high draft frame ? Mr. Sington : About 140s but the gauge is wider. M r. Roscoe : Would Mr. Sington tell us his opinion about fly frames ? I remember taking a City and Guilds of London Institute examination and one of the questions was, “ What is your opinion about fly frames ? ” I replied that fly frames were a necessary evil and for a long time I wondered what the examiner thought about it. I saw at Shiiley Institute 150’s yam from a draw frame sliver. The yam was better in appearance and stronger than yarn produced through normal passage of fly frame. Mr. Sington : Was it being produced commercially ? Mr. Roscoe : Experimentally, but not commercially. Mr. Grogan : Mr. Roscoe saw it being done by expert individual attention. But 500 spindles per frame as against 6, and much cheaper labour would not give the same result. Mr. Roscoe : If you used three passages of fly frames I admit you get a better yam than with one. The sample spun with no passage at all was the best. Why should it be better with no fly frames ? M r. Goddard : Twist put in at the fly frames is detrimental to the result. Mr. Bromiley : Twist is not detrimental, but is necessary. Mr. Roscoe is raising a very important point. I had here in Bolton, in 1928, yams produced by the Hartman system with 240 draft from Indian Cotton and those yams were relatively good. The point was, however, that when questions were raised in connection with the economics of production in Germany at that time the cost of production was greater than in connec­ tion with the ordinary system of drafting. It always appeared to me rather puzzling and personally I had the impression up to 1935 that the textile machinist in this country definitely praised the three passage speed frame because they sold the machines. That was my feeling, but on investigations which we carried out I think he would bear me out that in connection with spinning in Bolton we found that in connection with the cotton used in this area that the three frames gave a better yam. It is a problem from the spinner’s point of view of the three frames but then the three frames give us a better yam by a continued inter-mixing just as I have a f efeling that your feeding of laps by draw frame, though good in principle, would not give the quality of yarns which we are used to producing. Personally I believe that intermixing is very vital to us in the production of quality yarns. We have had terrific drafts and Mr. Sington has mentioned the fact thatin 1921 he came in contact in Italy with frames of 17J draft. I think we have shouted too much about high drafting and we should find another term. Mr. Sington : Under identical conditions there was a slight tendency to better strength. Each doubling helps. Mr. Bromiley : I would like the machinist to give the people generally something to bite on. I still am under the impression that the speaker said that he would not like to say which was the best system. This, of course, varies with conditions. Mr. Noguera : What is the best yam ? We did some experiments on yarns and we found that when using three processes of flyer frames we had better yarn for testing, but this did not work as well on the spinning, weaving or doubling processes, because the more processes you have on the flyer, the more piecing in the subsequent processes, so we thought we should cut out as many processes as possible. M r. Holt : This discussion seems to have developed largely on short-cut drafting and spinning as against ordinary spinning. There is a lot to be said for short cut. For the production of quality yarns the Bolton spinners are advised to stick to three. In fact I go so far as to think that anyone going to build a new mill would be advised to put in short cut machinery. We, in industry, have been faced with shortage of operatives, consequently, we must reduce our machinery to a minimum and if we can cut out passages we reduce to the same extent the personnel required in the mill to maintain P 22 Proceedings

production. Short cut systems are well worth considering. We must concentrate on large packages, high drafting and a reduction in the number of operations and operatives employed. Member : Will you enlarge on the statement regarding opening and scutching machinery ? Would you include in those particular points, bale breakers ? Mr. Sington : I am referring to beaters when I mention cleaning points. Member : Can you give us a specimen arrangement of machinery ? Have you any ideas for the automatic removal of dust from card ? It is impossible to get people to do dirty jobs. Mr. Sington : I think you can remove a lot of dust by pneumatic methods. Mr. Noguera : Mr. Sington reported rather at length about the single process speed frames used more in U.S.A. than anywhere else. Mr. Sington finds the results to be inferior when one single process speed frame is used. But I think it is important to know whether the drafting systems were somewhat comparable to those used in America. Much depends on how you perform the draft. If you are to do it with one instead of three it is easier. You must compare results claimed in America by using comparable drafting. Mr. Sington : The system I am referring to is practically identical to that used in America. But it is this extra doubling that always seems to have the effect of improving yarns. Mr. Noguera : Many in U.S.A. have Casablanca’s own drafting. Mr. Sington : Whitins system is comparable with Casablancas. M r. Holt : Referring to the question of the number of cleaning points in the blowing room, can you give us the best line of machines ? Mr. Buckley : Four blending Hoppers, feeding on to a conveyor lattice, (b) Hopper Feed, (c) Single Porcupine Opener, (d) Crighton Opener, (e) Double Openers, (f) Scutcher, having one cleaning point at c, d and f, and two at e, giving a total of 5 for American cotton. Member: : Is high drafting more sensitive to atmosphere than the normal drafting ? Should not high drafting together with air conditioning, go hand in hand ? Mr. Sington : Yes. Mr. Draper : You referred to your conversation with Dr. Balls when stressing the importance of the fineness of staple fibre. In recent months some figures have been published in the Manchester Guardian which show the colossal strength which is obtainable from this fine type of Egyptian cotton. It is stronger in yarn than is obtainable from Sea Island. It has been said that it is not so important to have good yam if you weave your own yams. I am a spinner-manufacturer and I attach a great deal of importance to spinning yam. I agree when you say that if you cut out processes you tend to bring down the strength, and the spinner-manufacturer may be not so much concerned with cutting out processes, but will be concerned with using high draft mechanism as the best drafting motion. You can reduce the value of your cotton, keeping draft normal and produce a yam of a given type; you can use it to cut down cost; or you can use it to improve your product. I think if you are a 'Spinner-manufacturer and quality means anything at all you are going to use a high draft for better yarn, better cloth and better selling value. With regard to the size of packages, this I think is bound up with wages. I believe that if we are goingto stick to small packages, we shall require more floor space and more speed. We should increase packages to the maximum to make us less dependent on the lower paid operatives. If the production of the mill is going to depend on the lowest paid operatives then in 1950 we shall be courting disaster. We must increase the package and cut down the juvenile jobs. Mr. Goddard : You started off by talking about our machinery being good as compared with American machines. All right they may be, but not in the finish. Mr. Sington : I have had a curious experience on that point. Two U.S.A. machinists came over and asked would it be possible to see your works. It was not convenient but they saw the showrooms and had already seen one mill in Bolton. They said: “ We cannot afford to finish our machinery like that. If we did we should be in the bankruptcy court.” Mr. Buckley : What sort of machinery are you referring to, Mr. Goddard. Mr. Goddard : Winding machinery. Mr. Warburton : I went to Germany in 1935 and X went to see a mule which was supposed to do six draws a minute on waste : but it did not. But I say this, that they were supposed to be good and well finished. Mr. Noguera : With regard to the high drafting German machines, they only make machines at Hartmans on licence from Casablancas. Lancashire Section

Mr. Hayes : I have read with interest the American report and I might say at the outset that I most thoroughly and completely agree with all said. May I say in reply to Mr. Goddard, referring to the condition „and quality of machinery, that one of the largest firms of textile machinists in U.S.A. produce machinery pattern for pattern, to that done in this country. I would like to ask, are textile machinists in this country as keen in watching Americans as they are in watching us. X came away with the conclusion twenty years ago that textile machinists in this country were behind in quite a lot of things. I felt convinced that textile machinists in this country were not watching the States. The Americans constantly send people over to find out the improvements in this country. They copy with a view to improvement. Textile machinists have been going ahead now for some considerable time and more so since the merger, but are the textile machinists in this country keeping an eye on the Americans ? Mr. Sington : The Merger is alive to the machinists over there. They take things from us and we take things from them on licence. Mr. Hayes : Have the textile machinists in this country considered the type of roving frame, without weights, which is being manufactured in America ? Have we considered that of any use ? Mr. Buckley : I regret that at the moment we cannot say anything about it. Member : I think the trouble is that some of Platt’s machines are made too well and last too long. Machinery was running on the continent in 1856 and still running in 1920. I think if you had not made them so good for lasting purposes they could have been improved upon. Mr. Sington : Yes, I quite agree. Mr. Bromiley proposed a hearty vote of thanks to Mr. Sington for the talk which he had given. The Chairman expressed the thanks of the Section to Bolton Education Department, and the Principal of the College for the excellent accommodation which had been provided. p 24 Proceedings

Reviews The Teaching of Mathematics to Physicists. (Report of the Joint Committee of the Mathematical Association and the Institute of Physics). 20 pp. (Reading: The Institute of Physics). Gratis. In view of the widespread interest being taken at present in post-war University education, the appearance of this report is particularly timely. The Committee was set up to examine a problem of which the urgency increases progressively as new fields of physical knowledge are explored: how much and what kind of mathematical training is necessary for the prospective physicist, taking into account the fact that he must spend some of his time learning physics. The solution proposed by the Committee is a sort of “ utility ” mathematics, shorn of the frills of rigour and elegance which, however satisfying to the mathematician, are apt merely to irritate those to whom mathematics is only a useful tool. The physicist, they argue, requires a certain degree of mathematical dexterity, but far more a wide knowledge of the content of mathematics and of the techniques available for the solution of practical problems; and if a theorem appears reasonable (physically) in the circumstances in which he has to use it, he may well dispense with a rigorous proof. He must, in short, be something of a mathematical Jack-of-all-trades, and if, there­ fore, master of none, at least capable of competent work in any particular part of the subject when the necessity arises. The type of course which the report visualizes is outlined in three schedules, and is based on a minimum standard at entry corresponding to a pass in mathematics in the Higher School Certificate. Assuming that about one-third of the student’s working time will be devoted to mathematics, a bare minimum (Schedule A) is given which would require about two years work by the least mathematically-minded. The better students should be able to cover further ground (Schedule B) in the three years of an Honours Physics course. The third Schedule is adapted for post-graduate students or for those who may wish to study the more theoretical parts of physics. (The needs of prospective mathematical physicists are not considered in the report; these are normally trained by the Mathematics Departments as applied mathematicians.) The actual teaching should remain the responsibility of the Mathematics Depart­ ments, but the teachers should be in sympathy with the more practical outlook of the physicist. Examinations are also dealt with. Questions designed to test technique should be of a straightforward character, and breadth of knowledge should be tested by questions of a general type, to be answered, perhaps, in the form of essays. A specimen paper containing questions of this kind is given. The Report has been approved by both sponsoring bodies. H . J. W o o d s .

Livestock Improvement. J. E. Nichols. Oliver and Boyd Limited, 1944, 10/ 6. The purpose of the book is stated in the author’s preface. “ Formal genetics does not always provide a satisfactory or convenient approach to an under­ standing of the principles involved in questions of livestock improvement and selection. The breeder finds it too remote at many stages from practical applica­ tions and bearings.” The author attempts “ to outline the principles and to indicate how the genetic and environmental concepts are interwoven in the idea of stock improvement.” Before suggesting how far this attempt succeeds, a brief classification of the information contained in the “book must be made. There are fifteen chapters, the first two dealing chiefly with general aspects of breeding, and these form an excellent introduction. The chapter following on " How Inheritance Works ” explains in condensed form, the gene concept, the role of the sex chromosomes and the importance in breeding of distinguishing between the appearance (phenotype) of an animal and its hereditary or genetic constitution (genotype). Considerable space is then devoted to gene effects, followed by chapters dealing separately and in fair detail with environmental and genetic aspects of breeding; breed construction, hybrid vigour, line breed­ ing, performance and progeny testing are all discussed. Among examples of the inheritance of characters of economic importance, some recent knowledge on the inheritance of certain fleece characters is given. Notes and Announcements P25

It is admittedly difficult to explain simply, the workings of inheritance, and all but the most progressive and scientifically-minded breeders will find some descriptions, for example in the chapters on gene effects and interactions, very difficult to follow. To the student, the experts on animal husbandry and the really progressive and thoughtful breeder, the book should prove useful. In consideration of livestock improvement there is too often " a too facile assump­ tion that progress in any direction can be attributed mainly to selective breed­ ing or to changed external circumstances.” A considered statement which dis­ cusses problems of improved economic performance of domestic stock in terms of the interplay of genetic and environmental influences, is badly needed. The author supplies this statement, and his claim for the book in this respect is fully justified. The latter chapters such as for example chapter XV on " Type and Environment,” give much information of sound practical value governed by a balanced approach to problems of livestock improvement: it is this viewpoint which gives to the book more than ordinary merit. ^ g W i l d m a n Notes and Announcements Additions to the Library The following publications have been received in the library: — Talks on Rayon. Published by The Cotton and Rayon Merchants Asso­ ciation, Spring Gardens, Manchester, 2. Price 12/ 6. 128 pp. A series of seven technical lectures on ( 1) Viscose Rayons and their characteristics. (2) Acetate Rayons—their properties and possibilities. (3) Cuprammonium Rayons—their place in the rayon family. (4) Rayon Staple— the field of development. (5) Rayon Weaving and Fabric Development. (6) The Dyeing and Finishing of Rayon Woven Fabrics. (7) The Printing of Rayon Woven Fabrics. By H. J. Hegan, W. A. Dickie, A. R. Knight, H. Ashton, R. S. Greenwood, P. A. Holt and H. S. Coleman, respectively. Nylon Yarn. Its Properties and its Processing. Trade Booklet published by British Nylon Spinners Limited. 47 pp. El Futuro de la Lana. The Future of Wool. By Professor Paul Link, Buenos Aires, February, 1944. 70 pp. In Spanish and English. An analysis and study of the Argentine wool and sheep production. The future of wool in post-war days. A graphical illustration of the wool and sheep production in the different provinces and territories. Annual General Meeting The Annual General Meeting of the Institute will be held at the Midland Hotel, Manchester, on Wednesday, 2nd M ay, 1945. Full details of the day’s programme, which includes a Luncheon and the Mather Lecture, will be supplied to members in due course. Mather Lecture The Mather Lecture, which is to be held in conjunction with the Annual General Meeting on 2nd M ay, 1945, will be delivered by Dr. C. J. T. Cronshaw. Election of Officers, 1945 The names of Council members due to retire during the present year are given in the following list: H. Ashton (Rochdale). J. R. S. Goodall (Stockport). H. Bromiley (Bolton). F. C. Harwood (London). WT. B. Crompton (Lytham). S. Kershaw (Bradford). A. Draper (Salford). T. H. Robinson (Bradford). N. C. Gee (Dewsbury). J. Williams (Nelson). There will be eleven vacancies in all as one casual vacancy was filled during the year. If a ballot is necessary, therefore, the first ten candidates who are elected will serve for a period of three years, and the eleventh candidate for a period of one year. The election will take place at the Annual General Meeting and nomination forms will be supplied to members of the Institute with details of the meeting. The Council has nominated Mr. T. H. McLaren, of Dundee, for re-electiofi as President for the year 1945-46. The names of members nominated for P 2 6 Proceedings election as Vice-Presidents are Mr. W. Kershaw (Manchester), Mr. W. W. L. Lishman (Todmorden), and Mr. W. H. Webb (Co. Antrim).

Examinations 1945 Applicants for Associateship who have been referred to the examinations should note the following dates on which the examinations will be held in 1945: Preliminary Examination—Wednesday, nth April. Examination in General Textile Technology—Wednesday, 16th M ay. Applicants desiring to be candidates should complete an official entry form and send it to the Acting General Secretary of the Institute at least one calendar month before the date of the examination.

Vacancies For details of vacancies see page iii of the cover.

Diplomas Elections to Fellowship and Associateship have been completed as follows since the appearance of the previous list (December, 1944, issue of th e Journal): FELLOWSHIP OSWALD POMFRET, A.T.I., Chairman, Grove Towel Co. Ltd., Ramsbottom. ASSOCIATESHIP JvORMAN FREDERIC CROWDER, A.M.C.T., A.R.I.C., Research Chemist, Tootal Broadhurst Lee Co. Ltd., Manchester. BHAGAVATIPRASAD BALUBHAI JOSHI, Additional Controller, Textile Commissioner, Government of India, Department of Industries and Civil Supplies. FEATHER BRUCE MURGATROYD, In H.M. Forces, formerly with A. R. Harrison & Co. Ltd., Keighley. LEO RIEGELHAUPT, M.Sc., Research Assistant, Textile Department, Leeds University. JACK WILLOCK, A.M.C.T., Senior Laboratory Assistant, Chamber of Commerce Testing House, Manchester. Institute Membership The following applicants were elected to membership at the February meeting of Council: O rdinary. David Abraham, Manikchand’s Bungalow No. 1, Modikhana, Sholapur, India (Bleaching and Finishing Master, Lakhshmi Mills, Sholapur). William Harold Carter, Drumcrea, Well Street, Ainsworth, Bolton (Inside Manager, Doubling and Weaving, Ainsworth Cotton Co. Ltd., Moorside Mill, Ainsworth). Harold Chadwick, 1, Viking Street, Passmonds, Rochdale (Weaving Manager, Turner Bros. Asbestos Co. Ltd., Rochdale). Joseph Chadwick, 38, Cavendish Road, Chorlton-cum-Hardy, Manchester, 21 (Assistant Producer, Rayon Dress Goods, Nahums Fabrics Ltd., Manchester). Cuthbert Barwick Clegg, M.A., Shore Cottage, Littleborough, Lancs. (Cotton Manufacturer, Shore Mills, Littleborough). Horace Collier, 42, Woodgate Street, Bolton (Loom Overlooker, Vantona Tex­ tiles, Victoria Mill, Dean Street, Bolton). N. G. Devadhar, Bhide Colony, Railway Lines, Sholapur, India (Superin­ tendent, Lakhshmi-Vishnu Mills Technical School). David Duncan, John Shields & Co. (Perth) Ltd., Wallace Works, Perth (Managing Director). Notes and Announcements P 27

Emest Felix, 274, Old Bedford Road, Luton, Beds. (Managing Director and Secretary, R. Westly & Co. Ltd., Luton). Thomas Horsburgh Gibson, Messrs. Gibson & Lumgair Ltd., St. Mary’s Mills, Selkirk (Woollen Manufacturer). George D. Hailey, 82, Links Street, Kirkcaldy (Proprietor, Geo. Hailey & Co., 30, Nicol Street, Kirkcaldy). Herbert Arthur Hargreaves, West View, Great Howarth, Wardle Road, Roch­ dale (Technical Assistant, Weaving Division, Turner Bros. Asbestos Ltd., R ochdale). Frank Richard de Garrs Hewitt, 180, Manchester Road, Rochdale (Technical Assistant to Spinning Manager, Turner Bros. Asbestos Ltd., Rochdale). Colin S. Kemp, Kemp Blair Co. Ltd., Gala Dyeworks, Galashiels (Director— D yer). Harold Kent, 52, Stafford Street, Stockport (Examiner, A.I.D., M.A.P., Crom- ford House, Manchester). James Macartney, The Falls Flax Spinning Co. Ltd., Cupan Street Factory, Belfast (Director). Robert Robson, M.A., B.Sc., The Cotton Board, Midland Bank Buildings, Spring Gardens, Manchester (Statistician). Gerald Shaw, B.Sc., Public Textile Testing House, White Linen Hall Building, Ormeau Avenue, Belfast (Officer-in-Charge, Textile Testing House). Patrick Henry Smyth, 28, Butterfield Avenue, Templeogue, Co. Dublin, Eire (Branch Manager, Lyons Ltd., 27, South William Street, Dublin). Frederick Herbert Stanger, Oak-Royd, Barnsley Road, Denby Dale, Nr. Hud­ dersfield (Woollen Spinning Manager, Z. Hinchliffe & Sons, Hartcliffe Mills, Huddersfield). Harry Huson Vlies, " Deeside,” Woodlands Road, Manchester, 16 (Sales Manager and Director, Howard & Bullough Ltd., Globe Works, Accrington). Willie White, 20, Little Lane, Bradford (Head Technical Dyer, Greenwood Dyeing Co. Ltd., Hind Street Dyeworks, Bradford). Harold Wilkinson, 346, Eccles New Road, Salford, 5 (Operative Cotton Spinner, John Ashworth ( 1902) Ltd., Newtown Mills, Pendlebury). Harry Wilson, A.R.I.C., 18, Clifton Crescent, Wheatley Hills, Doncaster (Chemist, British Bemberg Ltd., Wheatley, Doncaster). Junior. Robert Clendinning McConkey, B.Sc. (Hons.), 52, Knockvale Park, Belfast, N. Ireland (Teacher, Belfast College of Technology). Dennis Owen, 7, Walter Street, off Raleigh Street, Nottingham (Training Tech­ nical Salesman, G. Blackburns, Kirkwhite Street, Nottingham). John Comet Walton, “ Glenmere,” Pasturegate, Burnley (Undermanager and Salesman, John Walton & Son Ltd., Rake Head Mill, Burnley). Obituary The Institute regrets to announce the death of the following members'. T. Ashurst, Manchester. W. J. Cowden, N. Ireland. J. Schofield, Huddersfield. P 2 8 Proceedings INSTITUTE MEETINGS

LANCASHIRE SECTION F rid ay , 2nd M arch, 1945— B lackburn. 7.30 p.m. Lecture: “ Construc­ tion of Fabrics for Specific Purposes,” by F. T. Peirce, D.Sc., F.T.I. (British Cotton Industry Research Association) at the Technical College, B lackburn. F rid ay , 9th M arch, 1945—Manchester. 1.0 p.m. Lunch-time meeting at the Institute’s premises. " Narrow Fabrics for Industrial Purposes,” by W. A. Kenyon (Wm. K enyon & Son, L td .). T h u rsd ay , 15th M arch, 1945—Manchester. 6.0 p.m. Lecture: ‘‘X-Ray Studies of the Structure of Plastics,” by W. T. Astbury, M.A., Sc.D., F.R.S. (Leeds University) at the Grand Hotel, Manchester. Members are invited by the Manchester Section of the Society of Dyers and Colourists. S atu rd ay , 24th M arch, 1945—Manchester. 2.30 p.m. Annual General Meet­ ing. 3.0 p.m. Lecture: “ Motion Study,” by Miss A. G. Shaw (Metropolitan-Vickers Electrical Co. Ltd.) at the Institute’s premises. IRISH SECTION T h u rsd ay , 15th M arch, 1945— B elfast. 7.0 p.m. Lecture: “ Treatment of Water for Steam Raising and for use in Process .Work on Textile Plants,” by G. S. Irving, A.M.I.Chem.E., at the College of Technology, Central Hall, Belfast. The lecture will be illus­ trated by lantern slides. MIDLANDS SECTION S atu rd ay , 17th M arch, 1945—Nottingham. 3.0 p.m. Annual Meeting to be held at the Mechanics’ Institute, Nottingham. F rid ay , 23rd M arch, 1945—Leicester. 7.0 p.m. Lecture: “ Some Observa­ tions on the Finishing of Fabrics containing Wool and Synthetic Fibres,” by C. S. Whewell, B.Sc., Ph.D., F.T.I., at the Colleges of Art & Tech­ nology, Leicester. SCOTTISH SECTION F rid a y , 2nd M arch, 1945— E dinburgh. 7.30 p.m. Lecture: "The Mole­ cular Structure of Fibres,” by W. T. Astbury, M.A., Sc.D., F.R.S., at the North British Station Hotel, Edinburgh. S atu rd ay , 31st M arch, 1945— E dinburgh. Annual Meeting, followed by a lecture on “ Home Grown Flax,” by T. H. McLaren, President of the Institute. A film will be shown in conjunction with the talk. The meeting will be held at the North British Station H otel. YORKSHIRE SECTION T h u rsd ay , 15th M arch, 1945—B radford. 6.30 p.m. Lecture: “ Standard Testing on Yarns and Fabrics,” by A. W. Bayes, M.Sc., F.T.I., at the Midland Hotel, Bradford. T h u rsd ay , 22nd M arch, 1945— B radford. 6.30 p.m. Annual Meeting at the Midland Hotel, Bradford.

FEBRUARY 1945 s i THE JOURNAL OF THE TEXTILE INSTITUTE

TESTING CLOTHS FOR TENSILE STRENGTH PRACTICAL DETAILS IN TESTING CLOTHS FOR TENSILE STRENGTH

B y T h e S t a f f o f t h e T e s t i n g D e p a r t m e n t Shirley Institute, B.C.I.R.A. (Copyright by the Textile Institute) INTRODUCTION Woven fabrics are commonly examined for structural particulars such as weight and threads per inch and for freedom from the more obvious manufacturing defects. Cloth specifications also frequently require a standard of performance in particular tests, the most common of which is undoubtedly the tensile strength. The popularity of this test is understandable and reasonably well founded for not only is it readily carried out with the aid of a relatively robust machine, but it gives some check of several possible features of the cloth. The replacement of one variety or mixing of cotton by another, the existence of some degree of chemical, biological or mechanical tendering, the replacement of fibre by filling, irregularities or changes in construction not evident by simple inspection, can all produce changes in tensile strength that are revealed by tests on specimens. It is therefore important that the results of tensile tests on a cloth shall be as reproducible as possible not only on one machine but also between machines. It is known that there are real differences between the tensile strength results obtained with different machines and that the most important single factor responsible for these differences is the rate of loading of the specimen. It is customary, therefore, to specify the type of machine that is to be used and also the rate of loading or rate of traverse according as a machine having a constant rate of loading or a constant rate of traverse is to be used. The present article is not concerned with these aspects of tensile strength testing but with the variety of practical details which arise when tests are to be made on a given machine with a stated rate of loading or traverse. There are some rules which must obviously be observed ; the machine must be clean, lubricated, free from avoidable friction and looseness of parts and must give a reading as nearly correct as possible. There are decisions to be made about method when the choice of alternatives is not self-evident, for example, how specimens are to be prepared from “ bowed ” fabric, and whether fringes should be left on specimens. There are also rules of operation which must be followed and which are not so obvious ; for example, the necessity of mounting a specimen in the machine truly centrally in the grips. The practice of such rules distinguishes the skilled machine operator from the unskilled. Like many machines the tensile strength testing machine does not automatically give the same response to skilled and unskilled users. This account deals with practical points from the reception of a sample to the breaking of the specimen on the machine, and is divided into two parts; the preparation of specimens and the testing of them on the machine. The discussion of the second part is based upon the use of a horizontal Goodbrand Type C cloth testing machine ; many of the factors con­ sidered are peculiar to horizontal machines of this type but some are of more general application. S2 Standardisation

PART I. THE PREPARATION OF SPECIMENS (1) Number of Specimens Specifications usually state how many specimens are to be prepared and tested. In other instances, the number to be tested will depend upon the variability of the cloth strength and the accuracy desired but for general purposes a minimum of 5 warp and 5 weft specimens should be prepared and teśted.

(2) Location of Specimens in the Sample It is clear that if the results of the tests on the specimens are to be measures of the tensile strength of the sample, the specimen must be taken in such a way as to be representative of the sample.* It is scarcely possible to lay down precise instructions that will be suitable for every kind of cloth and all sizes of sample, but there are some rules which should generally be observed, and these supple­ mented by common sense and experience should prove sufficient in most instances. (a) Whenever possible, no two strips should contain portions of the same longitudinal threads. (b) Warp-way strips should not include the selvedge or threads less than 2 inches from the selvedge. (c) Defects or irregularities in the cloth should not be avoided. Their presence in specimens may be noted, if desired. (d) Senders’ marks on samples should be avoided if possible. These are instructions for normal working; in special investigations, where the average tensile strength of the body of the sample is not required, or if an official Specification demands it, they are disregarded. It is also obvious that (a) an d (b) do not apply to narrow fabrics. It may be helpful to give an actual example of the manner of selecting test strips. Fig. i shows the positions of strips in a fairly generous sample of cloth, *N.B.—Nothing is assumed about the strength of the bulk of cloth from which the sample has been taken. This involves another problem, the theory of sampling from bulk, which apolies to all kinds of testing and cannot be considered here. We are trying to get characteristic specimens from a given sample. Testing Cloths for Tensile Strength say 36" x 36" ; five warp and five weft strips have been marked diagonally for removal and reduction to test specimens that are to be tested 7" x 2*. W ith smaller samples or if more specimens are demanded the scheme must receive appropriate modification, the principle and rules given above being adhered to as well as possible. It may be observed that the arrangement in Fig. 1, th o u g h convenient in practice and probably sufficient for many purposes when a sample of this size is available, is not quite ideal; a more uniform distribution of warp specimens over the width can be ha*d by moving strips 2 a n d 4 inwards, and of weft specimens by moving strips 7 a n d 9 inwards. Enough has been said here, however, to indicate the considerations that are involved in selecting test strips ; in the routine tests of large quantities of fabric the selection of samples and of strips can be made the subject of a carefully planned arrangement. Weft-way Strength and the Cop-end Effect. An effect which it may be necessary to take into consideration is the variation of weft-way cloth tensile strength which sometimes arises when there are large changes in the tension of the weft from the end of one cop to the start of the next. If it should be required to assess the weft-way tensile strength of a cloth in which these cop changes are very clearly apparent the variability due to this cause may be allowed to exert its proper effect by adopting the following method. The average distance (C inches) between cop changes is determined. Then if S is the frayed specimen width in inches and N the number of weft-way specimens to be tested, the number of specimens which should include a cop change is given by S xN/C, the nearest integer being taken ; one such specimen should always be prepared. The cop changes should be located within the specimens according to the following scheme.

Number of specimens which include a cop change Position of cop change across the specimen width 1 One central. 2 One central, one a quarter the way across. 3 One central, one a quarter and one a third the way across. 4 One central, one each an eighth, a quarter, and three-eighths the way across. (3) Dimensions of Strips It is rarely practicable to remove from the sample in one operation a piece of cloth which has the correct specimen dimensions and which can be tested im­ mediately. Almost always it is necessary to take strips of cloth from the sample ; these strips are purposely made larger than the specimens which are subsequently prepared from them by fraying or other means. W henever possible the strips should be 5 inches longer than the ‘ ‘ test length ’ ’; but if the sample is small this figure may bft reduced to a minimum of 3J inches ; without this extra length it would of course be impossible to grip the specimen. The greater allowance permits a projecting end to be held in a clip attached to a light spring balance so that the specimen may be at a known small tension at the instant of clamping.* The smaller allowance is sufficient for gripping but as it does not allow of the application of the definite initial tension, measurements of breaking extension are not as precise as when the longer specimen is used, except with stiff relatively inextensible specimens. When a strip of cloth can be frayed down to specimen width this is always done and generally the fringe is not cut down, for without it the threads at the edge are liable to jump out during a test, and a lower tensile strength may be indicated by the machine. It has been found that with most cloths the stabilising action is adequate if each fringe is J inch in width ; only with very heavy fabrics does it seem • desirable to increase this provision by stipulating a fringe of 15 threads width.

* Provided, of course, that the specimen is not stretched by the act of clamping. SĄ Standardisation

The general rule is that the strip width shall exceed the specimen width by \ inch or 30 threads, whichever is the greater. Table I shows that the J inch fringe is adequate for a wide range of cloths. If the cloth cannot be frayed, or only to a very limited extent, strips are prepared J inch above test width, or if there is evidence that the result will not be affected, the strip may be marked out for immediate detachment at test width. T able I Effect of Fringe Width on Strength

7 in. x 2 in. cloth breaking load, lb.

Direction Threads/in. Counts Crimp % Width of fringe, inch Fabric of test W arp W eft W arp W eft W arp W eft ife l ł i Bleached cambric ... Warp 94 100 51 52 10-1 7-0 34 _ 33 — Loom-state sheeting Warp 50 50 12 9 12-4 8-9 144 — 147 — Florentine khaki drill ...... W arp 82 50 9* 10 254 — 260 — 17-oz. Canvas W eft 50 31 14/3 14/3 231 3-3 471 — 474 — 32-oz. Conveyor belt (duck) W arp 30 19 11/10 8/5 30-5 3-2 787 828 916 893

(4) Marking of Strips and Specimens Whenever possible marking should be done before the strips are detached from the sample ; the confusion of strips or specimens from samples of somewhat similar cloths is thus avoided. The boundaries of the strips that are to be removed are marked on the sample with a soft pencil or crayon. A cardboard template can often be used to facilitate this work. Identification marks are also made with soft pencil or crayon on each strip so that they will remain visible on the eventual specimen. These marks should include the sample reference, the specimen number and the warp direction. It has been found convenient to use an arrow to indicate the warp direction on all 'specimens. The specimen number may also be put on the adjoining residue of the sample ; this allows the source of any specimen to be traced if abnormal results are obtained. Experience has shown that it is permissible to write such marks on medium or heavy weight cotton cloths. Light weight cloths should be marked with care, however, using a soft crayon ; danger of weakening by pencil marking seems to be particularly pronounced with fine nylon fabrics as Table II shows. T able II Mean Tensile Strength of 15 Strips of Nylon Parachute Fabric Number of strips in which failure lb. occurred at marking

Unmarked strips (30 strips) 110 0 Light pencil line across centre of strip ... no 2 Heavy peDcil line across centre of strip ... 106 6 Heavy writing on specimen 106 8 If any doubt exists, the marks should be outside the area that will be extended between the grips in the tensile test. (5) Detaching Strips from the Sample and Converting them into Specimens M ethod 1 (for cloths in which the thread directions are visible and which can be frayed down without great difficulty). The strips are cut from the sample with sharp scissors or shears. Each strip is frayed down by removing threads or parts of threads equally from the two long edges with the end of a mounted needle, care being taken to avoid distorting the specimen. This fraying is continued until the removal of another thread from Testing Cloths for Tensile Strength one side or the other would reduce the average specimen width below the specified value. Deep fraying of close fine fabrics is sometimes difficult; it is then generally permissible to trim off the fringe progressively as the fraying of such strips proceeds, leaving only a narrow fringe. The justification of this course lies in the difficulty of inducing lateral slippage of the longitudinal threads ; it is evident that less safeguard is necessary against such slippage in the actual test. With heavy fabrics having relatively few threads to the inch and in critically important tests it is desirable to note the number of longitudinal threads in each specimen. Method 2 (for cloths which cannot be frayed, e.g., filled or coated cloths). •If necessary, the direction of the threads is found by starting a tear in the sample. Thereafter the strip is brought to length by further tearing or cutting and to width by making another tear or cut parallel to the first. The strip is now reduced, if necessary, to a specimen of the correct test width by cutting parallel to the thread direction. • W hether the specimen has been prepared from the strip by fraying, cutting, or tearing, it will be seen that the sides of the strip are parallel to the longitudinal threads. If the original sample of cloth is “ bowed,” then the specimen that is to be tested will also be bowed. On the other hand if the cross threads are not at right-angles to the longitudinal threads the short sides of the specimen are not cut in the direction of the cross threads but remain at right-angles to the long sides. The method óf clamping bowed specimens will be considered in Part II of this article. (6) Conditioning of Specimens It is well known that the result of a tensile strength test depends upon the relative humidity of the air to which the specimen is exposed before and at the time of testing. Although formulae have been proposed* for correcting tensile strengths measured at one relative humidity to the value that would have been obtained if the test had actually been carried out at another relative humidity it does not appear that these formulae can safely be applied to cloths other than those from which they were determined and it is preferable to condition and test the specimens at the desired humidity. The obvious practical question in the conditioning of specimens is how long they should be exposed to the atmosphere of controlled relative humidity. The whole problem of the rate of change of moisture content in fibres, yarns, cloths, bales and, in fact, any size of fibre package is of great importance, and has been the subject of much fundamental research at the Shirley Institute ; the rate of change is more rapid at higher temperatures and is dependent also on the actual regain. In the present instance, if the consideration is restricted to the con­ ditioning of specimens in the usual testing atmosphere of 65 per cent ± I per cent. R .H . a n d 70° ± 2°F., and the specimens are supposed to be absorbing water vapour, having previously been in a drier atmosphere, then for any particular cloth the dominating single factor in the rate of change of regain is the difference between the actual regain and that which will eventually be reached in the controlled atmosphere. As the regain approaches this value the rate of absorption diminishes towards zero so that it is not possible to say that it will take so many minutes for a specimen of cloth to acquire the regain corresponding to the con­ trolled atmosphere ; tables can be constructed, however, which show how long it takes for a cloth to absorb, say 50 per cent, and 90 per cent, of the moisture that will eventually be absorbed. These tables are a simplification of the exact relations because the rate and therefore the time for fractional change are de­ pendent a little upon the initial regain ; nevertheless for practical purposes they offer a good indication of the progress of the conditioning : The time required for adequate conditioning of cloth specimens depends chiefly upon three factors, the weight and closeness of the cloth and the ease of access of the air to each specimen. It is evident that the middle members of a block of specimens will condition much less rapidly than specimens which ai*e •For example, by G. B. Haven, in “ Mechanical Fabrics” (1932). s6 Standardisation singly and freely exposed on both faces to the controlled atmosphere. In Table III are given the times for several freely exposed cotton cloths to achieve 50 per cent, a n d 90 per cent, of the increase of regain when R.H. was changed from 33 per cen t, to 65 p e r cent. T able III

Time in minutes for x % of regain increase Cloth * = 50 * = 9 0 3 oz. Cambric ... 1 5 4£ oz. Plain 4 22 14 oz. Railway cover duck 8 55 20 oz. Close heavy duck... 18 100 25 oz. Heavy duck 12 85 47 oz. Hosepipe ... 23 125 The times are roughly proportional to the weight of the cloths, though the close 20 oz. duck requires a rather longer time. A simple rule can be based upon these results. Provided that each specimen is freely exposed to the controlled atmosphere, the period of conditioning in minutes for cloths of average closeness should not be less than four times the cloth weight in oz. per square yard and for olosely woven fabrics not less than six times the cloth weight. It may be argued that a rule for conditioning ought to include the initial regain or the equivalent relative humidity because the driest cloth under the above rules will be furthest from being truly conditioned in the controlled atmosphere. Apart from the practical difficulty that the initial regain or corresponding relative humidity of a sample is not usually known, the rules given above are safe for a degree of dryness (33 per cent. R.H.) below which it is unlikely that samples will fall and they give a greater margin of safety with less dry samples. There is, of course, no objection to increasing the period of conditioning well beyond that given by one of these formulae, and longer minimum periods are in fact sometimes demanded by specifications.

PART II. TESTING THE SPECIMENS AND CALCULATING THE RESULTS (1) Range and Rate of Traverse of Machine It is undesirable with any measuring machine or instrument that the quantity which is measured shall give a reading which is only a small fraction of the whole scale. Not only is the percentage accuracy of the scale reading reduced because of the few units of scale that are indicated, but any friction in the indicating mechanism will increase the magnitude of error, even when steps have been taken to make allowance for such friction so far as is practicable. Horizontal cloth strength testing machines require careful calibration and checking for friction and are certainly of the class for which minimum scale readings should be pre­ scribed. At the Shirley Institute the rule adopted is that all the observed breaking loads shall be above one-tenth of the full load of the machine. It may be necessary to prepare extra specimens for preliminary tests if any doubt exists as to the probable tensile strength of the specimens. The rate of traverse that should be used is generally stated when specimens are being tested according to a specification and is then usually 18 inches per minute. It has been recognised, however, that, particularly with relatively inextensible specimens, there are undesirable inertia effects associated with this rate of traverse. The massive pendulum and its associated clamp have to move suddenly from rest and to produce such sudden motion appreciable force is necessary which is provided by the machine motor and transmitted through the traversing grip and the specimen. This force is extra to that simply required to hold the pendulum in a lifted position, and which is indicated by the pointer. It is evident therefore that the specimen at first sustains a load somewhat greater than the indicated load. It may and frequently does happen that the pendulum is given such a shock that it shows not only an initial lag but also a swinging Testing Cloths for Tensile Strength motion superimposed upon its steady motion. The magnitudes of these effects can be computed and agree with close observations of the pendulum (Cf. e.g., Bayes, Martindale and Woods, Journal of the Textile Institute, 1942, pp. S24, S53). No deep scientific knowledge is required to verify the existence of these undesirable motions ; the irregular swinging motion of the indicating pointer is visible to a casual observer. Similar considerations apply to the stopping of the pendulum when the specimen breaks. Evidently if the specimen breaks very suddenly the moving bob will not stop at the same instant but will over-swing somewhat and indicate a breaking load greater than the true breaking load. All these unwanted complications sink to a negligible level if a lower rate of traverse, e.g., 4J inches per minute, is employed. There are other reasons, however, which can be adduced in support of a lower rate of traverse, and as it seems desirable to emphasize these in view of the widespread use of the 18 inches per minute rate of traverse in official specifications the cases for the low and high rates of traverse are considered explicitly below. The case for a low rate of traverse, 4J inches per minute. (1) The inertia errors discussed above are practically eliminated for all ordinary fabrics. (2) Extension measurements can be made in a reasonably satisfactory m anner. (3) The results of the tests are more nearly equal to those obtained with machines having a constant rate of loading and with which the test is completed in about one minute. (4) The power demand is less and a smaller motor and drive can be fitted to the machine and so reduce its first cost. (5) The mode of failure of the specimen can be more readily observed. The case for a high rate of traverse, 18 inches per minute. (x) The stretching of the specimen to break occupies a shorter time, e.g., a specim en 7 inches long requiring i -8 inches movement of the traversing clamp would take 6 seconds to break at 18 inches per minute rate of traverse compared w ith 24 seconds at 4J inches per minute rate of traverse. But when it is con­ sidered what a small fraction this is of the whole time of testing from preparation of strips and specimens to the calculation of results, the gain appears insignificant. (2) It may be contended that the results of tests at a high rate of traverse have a special significance in view of the use to which the material may be put that is not shown by the low rate results.* Against such a suggestion it may be urged that the proper use of the strength test is to control quality and that its use as a means of predicting behaviour of the fabric under particular conditions of service is at least dubious. But even if this purpose were granted, the errors due to the inertia of the machine parts prevent any reliable measurements being made at such high speeds ; the end would have to be attained by some other machine, probably of a ballistic kind. The conclusion is drawn that the evidence as a whole is very greatly in favour of the use of a low rate of traverse, and it is much to be desired that there should be agreement on this point among those specifying and those making the tests.

(2) General Condition cf the Machine Although horizontal strength testing machines of this type are relatively robust they require reasonable care and attention if they are to continue to give good service. It is perhaps hardly necessary to insist that all the bright steel and iron surfaces shall be free from rust and protected with a thin film of oil and that all moving parts shall also be clean and properly lubricated .t The traversing grip should be firmly secured to the traversing rod by the nut, there should be no * The result at 44 inches per minute is only about 6 per cent, less than that at 18 inches per minute. ■f A thin non-gumming oil is to be preferred. s8 Standardisation wobble or uncertainty in the autographic device, and the indicating pointer must not be loose on its shaft. Dual range machines have a rider for the pendulum ; this must be correctly seated. The “ head ” grip of the machine should ride upon rollers ; after long use these may wear until there is surface sliding of the grip on the bed of the machine with much increased friction. The condition of these rollers should therefore be examined occasionally, so that they can be replaced when it becomes necessary. Owing to the thrust applied when clamping a specimen, the near side roller wears the more rapidly, so that, eventually, because the friction here becomes greater, the grip tends to rotate about a point in this side. The skewness of the grip'thus induced is likely to affect the breaking load of the specimens and is a sign that the rollers should be examined. There are several places where some friction in the machine is unavoidable ; they are discussed in the next section, and it will be sufficient here to observe that these frictions should be kept to a minimum by taking care that the moving surfaces are free from dirt or fluff and are suitably lubricated. (3) Calibration Strength testing machines require occasional calibration, say quarterly, to verify that the scale readings do represent as nearly as possible the load developed in the specimen as it is stretched. It is not unusual to find that the indicated load of a tensile testing machine is considerably different from the true value. So long as such a machine is unchanged in its error it can be used for internal purposes to check the consistency of production of particular cloths but it is obviously necessary to correct such errors when testing cloths to specifications. W hen the necessary equipment has been assembled it is not a difficult matter to calibrate a horizontal cloth strength testing machine. At the Shirley Institute it has been the practice to make a fairly searching check in which separate assess­ ments are made of the frictional resistances and of the correspondence of the scald reading with the actual- load. The friction in such machines is the sum of the frictions of the maximum indicating pointer, of the grip that is normally linked to the pendulum, of the extension slides, of the autographic device, and of the dashpot. It is possible to make a somewhat simpler test of the accuracy of the machine by the method described by Goodbrand in the Journal of the Textile Institute, 1942, page S39, if a suitable rate of traverse is employed. Both the extended and the short method are described in this article because although the shorter method will probably be adequate for rapid check purposes in most instances, the description of the longer method given in the appendix will define more clearly for users of such machines the sources of possible error. The shorter method of calibration. In this method there is no disconnection of machine parts. The machine is ready as if for ordinary testing and one end of a length of narrow fabric or a strip of wider fabric of adequate strength is clamped in the grip connected with the pendulum. The fabric passes over a pulley set on a bar between the two grips so that there is a horizontal portion proceeding from the grip and a vertical portion proceeding to a clamp and hook upon which weights can be hung. Appropriate weights are set on the hook but they are prevented from moving the pendulum grip by distance pieces set between this grip and the traversing grip. The clutch is now engaged so as to cause the traversing grip to move at a low speed, 4J inches per minute is suitable, whereby the weights are allowed to act upon the pendulum. The pointer reading is compared with the load and the process is then repeated for another load until the scale of the machine has been sufficiently covered. Since by this direct method all the working frictions enter into the calibration in a manner not unlike that of an ordinary cloth test, the dial readings should agree with the loads that are used. It is necessary to insist that the low rate of traverse shall be used ; if the weight is allowed to act very rapidly on the pendulum, the latter will over-swing although the effect will not be so great with a fabric connec­ tion as with a steel tape connection between weight and pendulum. Testing Cloths for Tensile Strength

Correctness of autographic readings. If the machine is provided with the autographic device it is necessary to check its accuracy. The load readings on the scale of a chart are compared with the dial readings at various deflections of the pendulum. Errors of zero or pro­ portionality are corrected by the adjustments provided for this purpose. The drum is connected to the traversing grip by its cord and the correspondence of movement on the chart and movement of the grip is examined. Any deviation from i : I proportionality is corrected by increasing or decreasing the packing on the drum. Care should be taken that the cord is not over-tensioned and does not over-ride.

(4) Testing a Specimen (A) Mechanical Operations. Immediately before testing a set of specimens it is desirable to lift the pendulum by hand until it is brought to its upper limit by contact with the frame of the machine ; the indicating pointer ought now to rest opposite a mark made ©n the dial at the last calibration. This operation serves two ends ; it gives evidence that the pointer has not been displaced on its shaft since the last calibration and it also shows that there is no obstruction to the free lift of the pendulum. Though the latter possibility may be considered most improbable in a Testing House it is less improbable in a congested industrial laboratory where there may be a tem pta­ tion to utilise the space under the machine for storage purposes and where the operator may be inexperienced and unsuspecting of the remarkably constant results that ensue when the specimens are broken after the rise of the pendulum has been prevented by a massive stop. ‘ Gripping the specimens. It is obviously of the utmost importance that the specimens shall be held by the grips so that, so far as possible, the recorded breaking load is not affected by the manner of gripping. It may arise that the specimens tend to break at the grips, an occurrence that is commonly held to invalidate a result or at least to cause it to be suspect; there are reasons, con­ nected with the " waisting ” of specimens, for supposing that this may be the expected manner of failure in certain instances, more particularly with short specimens of very regular extensible fabrics. The discussion of this effect is outside the limits of the present article which must be restricted to the features that are under the control of the operator and which can affect the result. The manner of gripping must be such that the specimen does not slip or become damaged or weakened. This means that the clamping pressure must be between certain limits ; these limits are set partly by the fabric, partly by the nature of any lining material in the jaws, and partly by the shape of the jaw. It is implicitly recognised in the advocacy of particular linings and particular forms of jaw faces that it is desirable to maintain these limits as wide as possible. In so far as the fabric is concerned, the chief difficulties arise with those specimens that have relatively straight longitudinal threads and highly crimped cross­ threads, which slip very easily, and with those strong specimens which are very smooth in surface, easily damaged and weakened by pressure. In so far as the grip and its linings are concerned, it is common experience that the control of clamping pressure within the desired limits is less readily effected without linings than with linings. It is true that grips having coarsely corrugated faces can be used which appear to give a more secure hold than a straight flat clamp ; their use, assisted by thin linings, may well be justified in many instances. The success of this form of grip may be partly due to the “ capstan ’’ effect, par­ ticularly when the total clamping force is not great; the tension on the tail is decreased rapidly by its passage with friction around the curved surfaces of the corrugations. If the grip acts in this way some slip will occur in the more highly tensioned parts of the tail and any measurement of extension will lose accuracy. That the mechanism of gripping with such corrugations must be tolerably compjex and include other factors is apparent, however, when endeavour is made to SIO Standardisation describe the state of the tail of a specimen clamped in such a grip at high total pressure ; the shortest distance between the faces varies around each corrugation and the fabric cannot be equally stretched and compressed at all points. A recommendation of corrugated grips must therefore be based upon the consistency of the results obtained and the apparent freedom from damage and slip rather than upon any confirmed theoretical basis. The ability of flat clamping faces to grip a specimen can be increased by cutting fine grooves in the surfaces at right-angles to the direction of motion, the idea being, presumably, that the grooves allow the grip to bed in the surface of the specimen. It is not difficult, however, witl^ such a clamp or even with the corrugated clamp to damage a specimen, and obtain a low result; such unlined grips must therefore be regarded as dangerous in the hands of any but skilled op erato rs. Damage and slip can be generally avoided by using suitable linings for the grip ; felt pads about J inch thick have been found the best material. The chief disadvantage is that the operator has to do extra work in compressing these pads between the jaws of the clamp and it is therefore desirable to keep the pads as small as possible by having sets for specimens of different widths. Convenient sizes are 7 in. x 3 in. for specimens 4 inches wide and 3 in. x 3 in. for specimens 2 inches wide. Red fibre has also been found to be a satisfactory lining material and for fine fabrics good results are to be had by thin card linings. Rubber is unsuitable. The preferred lining should be used with a corrugated or grooved clamp ; it would appear that this arrangement combines the advantages of good grip of the lining with high relatively uniform non-cutting pressure on the specimen. At the Shirley Institute the clamp faces have grooves about 1/200-inch depth and are spaced about 1/24-inch. With such clamping arrangements all except a very few fabrics can be securely and properly gripped. If slippage is feared it may be advisable to put light crayon marks across the specimen where it emerges from the grips to serve as indicators. Alignment of specimens in the grips. The inside vertical faces of the upper halves of the grips are provided with scales so th at each specimen can be clamped as n early as possible cen trally . T h a t th is is m o st im p o rta n t is show n b y th e results given in Table IV. T able IV Effect of Specimen Alignment on Breaking Load of 2-inch Webbing Distance off JR.H, grip ...... -f-J" -(-J' -f-J' 0 + J ' + J ' centre, inches \L.H. grip ...... -fj" -i-J' 0 — J' — Mean breaking load, 10 specimens, lb. ... 385 403 419 409 405 392 313 Whilst the central mounting of most specimens offers no difficulty, the |procedure with skewed or bowed specimens requires an arbitrary decision. The method adopted is depicted in Fig. 2 ; it is based on two principles (i) the line joining the gripped ends of a thread lies in the direction of the movement and

Fig. 2. (A) Ordinary symmetrical specimen with straight longitudinal threads and normal cross threads. (B) Longitudinal threads straight but cross threads skew. (C) .Bowed longitudinal threads of frayed or cut specimen with cross threads normal. (D) Bowed longitudinal threads with cross threads skew. Testing Cloths for Tensile Strength SII

(ii) the specimen issues from the centre of grip. No attem pt is made to distort the specimen by hand as it is being mounted so that the skewing of the cross­ threads or the bowing of the longitudinal threads is removed before the stretching commences. Quite apart from the practical difficulties that arise when such adjustments are attempted it would appear that they are based on a misguided idea that the strength of such rectified specimens will offer a guide to the strength of the cloth unaffected by these defects and possibly to the strength in service of normal fabric. This is to strain the purpose of testing ; it seems far better to assess the strength of a sample as it stands than to aim at some hypothetical value. Tensioning of specimens. The tension at which specimens are mounted in the grips is important in two ways. In the first place the tension developed in the specimen should be controlled if accurate measurements of extension are required. It is probably true that an expert operator can mount a specimen of most fabrics so that it is just taut and that very reproducible measurements of extension can be so obtained. For greater accuracy in extension measurements and where objective control is desired it is preferable to hold the specimen under - a definite tension before clamping. The method adopted is as follows. A bout 2 inches of one end of a specimen is put between a pair of felt pads and these are then placed in the “ head ” grip with the felts projecting about J-inch and with the specimen issuing from the centre of the grip. The grip is now closed by the lever-operated cam which has previously been adjusted to give an appro­ priate clamping pressure. The steel strip which connects the pendulum to the “ head ” grip is tautened by hand adjustment of the position of the “ head ” grip on the bed of the machine ; if this is not done there is likely to be an error in the extension measurement. The traversing grip is now brought to the “ test-length ” distance from the “ head ” grip ; this is quickly done if distance pieces have been attached to the grips, and if holes have been provided in the traversing rod to locate the clutch appropriately. The free end of the specimen is set between another pair of felts and placed between the clamping faces of the traversing grip. Before it is clamped centrally it is tensioned from the back of the grip with the aid of a spring balance and a clip at least as wide as the specimen, which are temporarily attached to the tail. The tension used may depend on the material to be tested but for general purposes J-lb. per inch width is imposed. In many instances the second aspect of tensioning, uniformity of tension across the specimen, is probably much more important than the total tension in the specimen. This is one of those points in tensile testing where it seems scarcely possible to substitute objective control for care and skill of the operative. Low results can be obtained by carelessly mounting the finer fabrics so that, though they lie apparently square in the jaws, one side or the other may be under greater initial tension. So far as the art of the operation can be reduced to description it appears to consist of observing the shape of the specimen as it is tautened, combined with such gentle hand feeling and adjustment of the tension across the specimen as will not produce any extension. Stretching and breaking the specimens. The maximum load pointer is set against the indicator pointer. If readings are to be made from the brass extension *cales these are slid into contact with the stops on the “ head ” grip. If an autographic record is to be made the recording pen is set in the writing position on the chart and a vertical line is made by hand-raising of the pen. This line marks the start of the extension. If the motor is not already running it is started and the screw traverse of the machine is engaged by the clutch so that the specimen is extended to the point of failure ; the pen is then lifted from the chart and the clutch is disengaged. The broken specimen is removed and stacked with others for any subsequent examination that may be necessary. (B) Observations and Calculations. (i) The reading of the breaking load indicated by the maximum pointer is noted. SI2 Standardisation

(ii) Snap readings of extension. The reading (S) of the pointer fixed to the traversing grip on the near side brass scale is taken when the specimen is judged to have attained its maximum load, usually indicated by a considerable break­ down of the specimen. (iii) Extension correction. At the end of the test the reading of the traversing jaw is taken on both the near brass scale (N) and the far side (A). (iv) When an autographic load/extension record is taken (ii) and (iii) are not observed but the extension at this load is read from the chart. T h e break in g loads of th e several specim ens th a t h av e b een te s te d are generally adequately described by reporting the mean and the variability. There are several measures of variability that can be given ; for specification work a minimum strength of a given number of specimens may be demanded, for general purposes the range of results is a simple and useful criterion. The breaking extension from the results of observations (ii) and (iii) above is calculated from the expression S + $(A —N). The extension thus computed or obtained from the chart as in (iv) is then calculated as a percentage of the original test length of the specim en. APPENDIX The Extended Method of Calibration* A set of weights is needed which will cover the range of the machine ; loom weights are convenient for this purpose. It is also an advantage to hav-e an I-girder about 6 feet long weighing 100 lb .; the loom weights can balance upon the top face of this girder. The loom weights should be checked and each adjusted so that its marked value is correct and not merely nominal. A flexible steel tape is required. This is conveniently i inch wide and about 15/1000 inch thick and sufficiently long to reach from the end of the steel strip attached to the indicating roller and head, over a pulley to a point from which the weights can be hung. The steel tape has a hole at one end for linking it to the machine strip ; the other end has a hook from which the weights can be hung. The pulley, which is necessary to convert the vertical pull of the weights into a horizontal pull on the pendulum, is conveniently provided by a ball bearing. That used at the Shirley Institute for loads to 400 lb. has external diameter 2 inches, width J inch and fits a J-inch shaft. It is mounted on a flat rigid bar which can be clamped on the bed of the machine so that the top of the pulley is level with the steel strip issuing horizontally from the roller in the head erf the machine. The arrangement is sketched in Fig. 3. When a calibration is to be done the operations are as follows. The extension scales and their locating screws are removed from the bed of the machine. The cord linking the traversing grip and the drum of the autographic device is dis­ connected. The traversing grip is slid to the motor end of the machine. By removing the link pin, the other grip is disconnected from the strip which usually connects it with the pendulum and load-indicating mechanism. This grip is then also slid to the motor end of the tester. The pulley and strip' are then arranged as in Fig. 3 ready for adding the weights tQ the hook. The friction pointer is rotated out of range so that its friction does not complicate the observations. The Siotor is run so that the actions of vibrations from this source in reducing friction may be included. A weight is then put on the hook and the steady reading of the indicating pointer is noted. It is important that the friction in the system shall not affect this reading and it is therefore desirable to tap the head of the machine to achieve this result. This friction ought to be small, say not m ore th a n 1 lb. on a 400 lb. machine. The friction arises in various places, in the pulley, in the main bearings of the pendulum, in the gear and bearings of the indicating pointer, and in the slides and pulleys of the autographic device. A measure of these combined frictions is to be secured by observing the pointer

* Results obtained by this extended method have been found to agree with those obtained by taking simultaneous photographs of the dial and an accurate spring balance used as a specimen at a rate of traverse of inches per minute. Testing Cloths for Tensile Strength movement from the position that is assumed under a slowly applied load to the position obtained by slowly decreasing the load. Having obtained a number of readings over the scale range of the machine, these are compared with the known loads that were applied after adding to the latter the total friction of the parts removed, measured as described below, namely the friction of the maximum indicating pointer, the friction of the grip that is normally linked to the indicating head, the friction of the extension slides if these are used, and the friction of the dashpot. If there is a nearly constant difference between these sets of figures which exceeds more than 1/200 of the scale range, the indicating pointer is detached and reset so as to reduce the discrepancy below this limit. If the difference between the two figures is such that it cannot be eliminated by setting the pointer it will be necessary either to construct a correction table or curve for use with the machine or to make appro­ priate alterations to the pendulum.

Friction in the Machine There are several parts of the machine the frictions of which ought to be known. That of the maximum indicating pointer is measured as follows : At a few points in the calibration of the machine the friction pointer is brought into contact with the indicating pointer before the latter is caused to move slowly forward under the action of the applied weight. The scale reading then obtained is less than that which results when the friction pointer is swung out of range. This difference ought not to exceed 1 lb. in a 400 lb. machine or 2 lb. on a 1,000 lb. machine. The friction of this pointer may also be tested by the following method. The glass cover which carries the pointer is detached from the head of the machine and is set in a vertical position with the pointer horizontal. The friction should be such that the pointer just begins to move under its own weight. The provision of adequate friction for this pointer is some safeguard against “ pointer fling,” an undesirable effect which occurs sometimes. Its cause is obscure but is probably connected with discontinuous failure at the short period of breakdown of the specimen. It may be detected by comparison of dial readings with autographic records or by careful observation near the end of the test. Standardisation

The frictions of the grip connected with the pendulum and of the extension scales on the machine bed are determined directly with the aid of the pulley, steel strip and dead-weights or with the aid of a suitable spring balance horizontally disposed. These frictions together should not exceed i per cent, or a t m o st 2 per cent, of the full scale of the machine. If, as is frequently done, the scales are removed for tests, the friction of the grip alone should be determined. The friction of the dashpot requires more lengthy consideration as it is the largest correction that, has to be made. The resistance to motion in the dashpot is two-fold ; there is ordinary friction evinced as the force necessary to overcome the binding of metal on metal and there is the viscous drag on the piston as it moves in the dashpot. The following results were obtained by measuring the load in pounds required to draw out the spindle of suęh a dashpot at various speeds. Speed of w ithdrawal, inches per m inute 2-5 7-6 12-5 15-0 20-0 24-0 30‘0 Force required, lb ...... 2-5 3-0 3'5 4-0 4-5 5'0 6'0 It is clear that at very low speeds the force does not fall to zero ; there is a friction of about 2 lb. These results were obtained by testing the dashpot separately on a table. When it was coupled to the pendulum in the machine and the calibration of the machine compared with that obtained without the dashpot it was found that this friction had risen to about 4 lb. ; the greater friction of the system on the machine might be expected since there is the possibility of lateral constraints at the cylinder as a result of the method of connection to the pendulum. The use of a dashpot on machines of this kind is admittedly a convenient means of absorbing the energy of the lifted pendulum at the end of a test, and those who make the tests no doubt prefer this arrangement to the use of the ratchet arm and pawl type of stop motion which necessitates manual release of a relatively heavy pendulum. It should be remembered, however, that this con­ venience haś been attained by some sacrifice of accuracy. As has been shown above, the correction for the dashpot is not truly constant but depends on the rate of increase of load, and whilst it is true that this secondary correction is relatively small and can probably be neglected in most instances, it is possible that circumstances may arise in which the drag or friction may become serious. For example, if the oil in the cylinder does not remain quite free from solid im­ purities the resistance to motion may increase considerably. If a calibration of the machine shows low readings of the pointer it is advisable to examine the condition of the dashpot before re-setting the pointer. Received 15/5/44 FEBRUARY 1945 T19 THE JOURNAL OF THE TEXTILE INSTITUTE

3—THE OPTIMUM CONDITIONS FOR SETTING STRAINED ANIMAL FIBRES B y J. R . H ind and J. B . S pearm an.

The permanent set which strained wool fibres acquire in steam or boiling water is due to two consecutive intramolecular reactions: disulphide bond breakdown, followed by linkage rebuilding1. Disulphide bond breakdown, which permits fibre relaxation, takes place in the following manner: — R .C H 2.S.S.CH 2.R + H 20 = R .C H 2SH + R .C H 2.S0 H ...... (i) The relaxed structure is then stabilised by the formation of cross-linkages between the peptide chains through the combination of the basic side-chains of lysine and arginine with either the sulphenic acid, or the aldehyde to which it gives rise on decomposition, in accordance with the following equations2: — R.OEŁ .SOH + R'.NH2 = R.CH 2.S.NH.R' + H20 ...... (2) R .C H 2.SO H = R .C H O + H2S ...... (3a) R.CH 0 + R '.N H 2= R .C H = N .R ' + H 20 ...... (3b) As would be expected in terms of the above reactions, the extent to which strained animal fibres acquire a permanent set is an interesting function of the pH of the setting medium. At pH 1, permanent set cannot be realised because disulphide bonds are difficult to hydrolyse in acid media and the basic side-chains, being fully combined with acid, are not available for con­ densation with any sulphenic acid side-chains that may be formed. Maximum set and maximum permanence of set are realised at pH. 9-2*, presumably because of the ease with which disulphide bonds are hydrolised by alkalis, but the extent of set decreases rapidly with rise of pH above 9-2, suggesting that the aldehyde, into which the sulphenic acid decomposes in alkaline media, does not play so important a part in linkage rebuilding processes as the sulphenic acid itself. Against this view it might be objected that direct proof of the existence of -S-NH -linkages in set fibres was not given when the above chemical mechanism of permanent set was first suggested, but a survey of the literature has since revealed the following reactions’ in which — S-NR- linkages are formed by the action of amines on organic disulphides: — T 20 3— The Optimum Conditions for Setting

If, in fact, the aldehyde does play a minor part in setting processes, this is probably due not so much to its unsuitability as a cross-linking agent as to the fact that equations (i) and (3a) together represent only one of- many possible ways in which disulphides are decomposed by alkali, ways which are not as yet fully elucidated. Finally, strongly alkaline solutions must cause main chain hydrolysis, which would favour contraction of the fibres despite the formation of cross-linkages between the peptide chains. Since disulphide bond breakdown, whatever its type, and peptide bond hydrolysis both promote fibre relaxation, which is an essential preliminary to set, and since the number of cross-linkages required for a given degree of set must vary with the degree of relaxation, it is evident that the condi­ tions which give the maximum degree of set do not necessarily give fibres of maximum strength. But the setting conditions employed in practice must certainly be those which give the desired degree of set with minimum damage to the fibres. Unfortunately, the strength of fibres set in different ways has not so far been studied, and it is impossible to decide, for example, whether it would be preferable in practice to set yarns and fabrics at pYiy or ^Hc); a longer time of treatment would certainly be needed at pKy to give the desired degree of set, but the resulting degree of damage might be less than in the shorter time of setting at pUg. With such considerations in mind, an attempt has been made in the following investigation to define the optimum conditions for setting yarns and fabrics in everyday practice. EXPERIMENTAL The general plan of the investigation was to determine the rate of setting of stretched fibres in boiling buffer solutions at various p i t values, and then to measure the degree of damage sustained by fibres possessing different degrees of set. The two sets of results were expected to define the conditions needed to give maximum set with minimum aamage to the fibres. In the light of the results obtained, similar experiments were afterwards carried out with boiling water, steam and high temperature steam as setting agents, and the general validity of the deductions drawn from work on single fibres was afterwards examined in further experiments with the curled mohair yarns used in the manufacture of moquettes.

THE SETTING OF STRETCHED FIBRES (a) Material. Human hair was chosen for use in the experiments because of the uniformity of cross-sectional area of the fibres along their length. The intact root ends of fibres cut from the head of a-7-year old girl were purified by successive extraction with alcohol and ether in a Soxhlet apparatus followed by repeated washing in distilled water. (b) Procedure. A 7-cm. length of fibre was attached by means of sealing wax to light glass hooks and then calibrated by determining its load- extension curve up to 30 per cent, extension in distilled water at 22-2° C. The fibre was afterwards released, and allowed to stand for at least 30 minutes in distilled water, before being cut away from the hooks and remounted in the stainless steel setting frame, which has been described elsewhere4. After its length had been measured by means of a travelling microscope, the fibre was stretched 40 per cent, in distilled water at 250 C. and then transferred to a boiling buffer solution of known pH for the desired length of time. The setting frame carrying the set fibre was then washed in three successive 500 cc. lots of cold distilled water, and after the frame had been dried by means of filter paper, the precise length of the fibre was re-determined. The fibre was then slackened by screwing down the upper clamp, after which the frame was transferred to boiling distilled water for 2 minutes. In all cases, the fibre underwent considerable contraction during the 2 minutes’ immersion in boiling water, and the degree of set retained by the fibre was determined by re-measuring its length as soon as both frame and fibre were strained Animal Fibres— Hind and Speakman T 2 I dry. Similar determinations of retained set were made after 15, 30 and 60 minutes’ release in boiling water, and typical results for a fibre which was set in a citric acid-disodium hydrogen phosphate buffer solution at pH y-oz fo r 120 minutes are given in Table I. T able I

Time of release Set in boiling water (% of original (minutes) length)

0 40-3 2 28-9 15 26-5 30 24-1 60 21-9 In its later stages, contraction of the set fibre is extremely slow, and the set retained after 60 minutes’ release in boiling water was assumed to be true permanent set; quite certainly, no further contraction can occur in cold water. The set fibre was next removed from the setting frame and again attached to glass hooks so that its load-extension curve could be redetermined iti dis­ tilled water at 22-2° C. A measure of the damage sustained by the fibre during setting and subsequent relaxation was then obtained in the following manner. The work (Wu) required for a 30 per cent, extension of the original untreated fibre was estimated, in arbitrary units, by measuring the area between the appropriate load-extension curve and the axis of extension up to 30 per cent. A corresponding value (Ws) was likewise obtained for the same fibre after it had been set and relaxed. The quantity Wu—W„ does not, however, give a true indication of damage, because the cross-sectional area of the set fibre is different from, usually smaller than, that of the untreated fibre, and even if the fibre were undamaged in setting and relaxa­ tion, Ws andWu would not be identical. The quantity Wsx > where S is the percentage set of the fibre, must therefore be used instead of W„ in any comparison with Wu. In addition, the lengths of the untreated and set fibres used in determining their load-extension curves were necessarily dif­ ferent, not merely on account of setting, but because, after the first load- extension curve had been determined, the fibre was detached from the glass hooks, mounted in the setting frame, removed, and finally again attached to glass hooks for the determination of the second load-extension curve. Atten­ tion must, therefore, be confined to the work per unit length of fibre stretched, i.e. to Wu/Luand Ws/Ls x , where L„ and Ls are the measured lengths of the untreated and set fibres, respectively. An indication of the degree of damage sustained by the fibre during setting and relaxation is thus given by the quantity: —

W u/L u - W s/L s x (-° ° + S) W s L u D = 100 x 100= 10 0——- . — . (100+ S)

W u / L u " 8 For convenience, the determinations of rate of setting and degree of damage will be discussed separately. (c) The Rate of Setting of Stretched Fibres at Different pH Values. Using the above procedure, stretched fibres were set for times ranging from 3 to 480 minutes in boiling buffer solutions at pH values ranging from 3 to 10. Citric acid-disodium hydrogen phosphate buffer solutions were used for pH values ranging from 3 to 8, a 2 per cent, borax solution for pH 9-24 and a boric acid-sodium hydroxide buffer solution for pH 10-03. The pH values of the solutions were measured at 22-2° C. by means of the glass electrode. As already indicated, the set retained by the fibres was determined after T22 3— The Optimum Conditions for Setting

2, 15, 30 and 60 minutes’ release in boiling water, but only the last of these values is recorded in Table II. Except in two cases (6 and 15 minutes at />H 5 '98), each of the results is the mean of at least two closely agreeing observations on different fibres. T able II

The results are illustrated by the curves of Fig. i, from which experimental points have been omitted for the sake of clarity. The rate of setting increases steadily with rise of pH of the setting medium, and the degree of set increases with increasing time of boiling, except at pH 9-24 and pH 10 03, where the degree of set decreases with increasing time of boiling after a sharp initial rise. Further, higher degrees of set can be realised at pH 7 and pH 8 than at the higher pH values, and the results give a first indication that it may be unwise to exceed pH 8 in commercial setting processes. Strained Animal Fibres— Hind and Speakman T 23

(id) The Damage sustained by Fibres Set at Different pH Values. It will have been observed that fibres set for short times in solutions of low pH values contract to lengths less than the original length on being released in boiling water. For the purpose of this investigation it was not found neces­ sary to measure the damage of all the supercontracted fibres, and the results of Table III do not cover all the fibres of Table II. Table III

Fig. 2 The results are illustrated by the curves of Fig. 2, from which experi­ mental points have again been omitted for the sake of clarity. In all cases, the degree of damage first decreases with increasing time of boiling, owing to the formation of an increasing number of cross-linkages after the rapid T24 3— The Optimum Conditions for Setting primary breakdown of disulphide bonds. Beyond a certain time, however, the strengthening effect of new linkages is off-set by a damaging effect, pre­ sumably main chain hydrolysis, and the degree of damage then increases with increasing time of boiling. In general, the time at which damage is at a minimum decreases with increasing pH of the setting medium, and the sharp­ ness of the minimum on the curves is greatest at the highest pH examined.

Least damage is given by the pH 8 buffer, the minimum on the curve being at about 85 minutes. Above 60 minutes’ boiling, however, the set given by the pH 8 buffer exceeds that given by any other solution used, as may be seen from Fig. 1. It seems probable, therefore, that a medium having a pH value in the neighbourhood of 8 will be the most suitable for use in practice as regards the attainment of maximum set with minimum damage to the fibres. From Fig. 3, where the minimum values for the damage given by the various Strained Animal Fibres— Hind and Speahman T25 buffers are shown as a function of pH, it appears that least damage would be caused by a pH 7 ■ 5 buffer, although the curve is very flat between pH 6 • 5 and 8-2. Reference to the curves for pH 7 and 8 in Fig. 1, too, indicates that the pH 7-5 buffer would be capable of giving a high degree of set, although in a longer time than at pH 8. From Fig. 4, where the time at which damage is at a minimum is shown as a function of the pH of the setting medium, it is evident that the optimum time of boiling in the case of a pH 7 • 5 buffer is 132 minutes, compared with 85 minutes for a pH 8 buffer. Whichever buffer is employed in practice, the time of boiling must be strictly controlled if a high degree of set is to be obtained with minimum damage to the fibres. As the optimum pH for setting is so near neutrality, it was thought advis­ able at this point to determine the rate of setting of strained fibres in boiling water, steam and high temperature steam, as well as the damage sustained by the fibres, for comparison with the behaviour of fibres in a boiling buffer solution at pH 7-5. (e) The Setting of Stretched Fibres in Boiling Water. The general pro­ cedure adopted in these experiments was identical with that described above, Hysil beakers being used to prevent the pH of the distilled water rising during the prolonged periods of boiling which were sometimes used. As measured by means of the glass electrode at 22-2° C., the pH of the water at the end of the boiling period was found to vary between 5 • 23 and 5-57 in the various experiments. Data for the degree of set and the damage sus­ tained by the fibres are given in Table IV, illustrated by Figs. 5 and 6, respec­ tively. As in all other cases, the experiments were carried out in duplicate.

T able IV

Time of Percentage set after setting 60 m inutes’ release Damage (minutes) in boiling water (D) 7 -7 -0 78-4 15 -3 -3 80-2 30 3-8 80-4 60 8-7 76-4 120 16-7 68-9 180 20-6 64-4 240 19-4 61-4 300 21-7 58-0 360 23-0 59-7

The rate at which fibres acquire a set in boiling water is extremely small. Damage is at a minimum after 312 minutes’ boiling, but the set acquired in this time is no more than 22 per cent. Under critical conditions, the damage sustained by the fibres in boiling water is very little less than in a boiling buffer solution at pH 7-5, where the time of boiling associated with minimum damage is 132 minutes, and the degree of set is 25-7 per cent., compared with 22 per cent, for boiling water. There can be no doubt, there­ fore, that a buffer solution at pH 7 • 5 is very much superior to water as a setting medium. (/) The Setting of Stretched Fibres in Steam. In this case, the frame carrying the stretched fibre was introduced into a wide glass tube, which was provided with inlet and outlet tubes for the steam from a separate reservoir of boiling distilled water. After the desired time of steaming, the frame was removed and the fibre released in boiling distilled water for 60 minutes in the usual manner. Values for the set acquired and the damage sustained by fibres steamed at 40 per cent, extension for various times are given in Table V illustrated by Figs. 5 and 6. T2Ó 3— The Optimum Conditions for Setting Fig. 8

To face page T27 Strained Animal Fibres— Hind and Speakman T27

T able V

Time of Percentage set after Damage setting 60 m inutes’ release

15 -3 -4 75-8 30 5'4 72-8 60 16-5 65-1 90 22-4 62-8 120 22-3 630 18Ó 24-1 61-4 240 24-7 62-9 300 23-8 64’5

As shown in Fig. 5, stretched fibres acquire a permanent set more rapidly in steam than in boiling water, but the set after 170 minutes’ steaming, which, as shown in Fig. 6, is the time for minimum damage, is only 24 per cent., compared with 25-7 per cent, for fibres set in a boiling buffer solution at pH 7-5 for 132 minutes. Not only so, but the damage sustained by the stretched fibres in steam (61 ■ 7) is greater than in a buffer solution at pH 7 • 5 (58-6). As a setting medium, therefore, steam is decidedly inferior to a boiling buffer solution at pH 7-5.

(g) The Setting of Stretched Fibres in High Temperature Steam. In the light of the preceding experiments, it seemed unlikely that high temperature steam would prove to be superior as a setting medium to a boiling buffer solution at pH 7 • 5, but since superheated steam is commonly used in setting fabrics, it was clearly desirable to examine its behaviour. For this purpose, the frames carrying stretched fibres were introduced into a small autoclave and exposed to steam at the desired pressure. The general procedure was to raise the water in the open autoclave to the boiling point, introduce two setting frames carrying stretched fibres into the space above the water, clamp down the lid, and then adjust the pressure within the autoclave to the desired value. As will be seen from Table VI, a considerable time was needed to build up the desired pressure after the lid had been clamped down, especially in the case of high pressures, and some time also elapsed before the setting frames could be removed from the autoclave after the escape valve had been opened at the end of the setting period.

Table VI

Steam pressure Time taken to Time taken to (excess above atmospheric attain pressure reduce pressure in lbs. per sq. in.) (minutes) (seconds)

5 3 10 5 95 20 8 145 30 11 190 40 14 210 50 17 225

For these reasons, it was found impossible to define with precision the manner in which the properties of stretched fibres are affected by steam at different pressures. An approximate indication is, however, provided by the data of Table VII, which were obtained by exposing fibres to steam at the specified pressures for a constant time in each series of experiments, no account being taken of the above delays in attaining and releasing the pressure. T28 3— The Optimum Conditions for Setting

T able VII

Excess Fibres set for 30'. Fibres set for 60'. Fibres set for 90'. steam pressure Set* Damage Set* Damage Set* Damage (lb./sq. in.) (%) (D) (%) (D) (%) (D) 0 5-4 72-8 16-5 651 22-4 62-8 5 13-5 68-9 22-6 59-4 24-7 61 0 10 25-9 62-7 26-4 58-3 28-8 60-8 20 25-9 63-4 27-3 62-7 29-0 70-5 30 28-6 66-4 27-5 71-8 27-7 80-9 40 27-0 78-2 • 27-4 86-8 ' 29-4 Fibres broke 50 25-9 87-2 28-1 91-0 28-7 93-0 * After 60 minutes’ release in boiling water. The best result, as regards damage, is obtained by exposing stretched fibres for 60 minutes to steam at an excess pressure of 10 lb. /sq. in. Under these conditions, the damage (58-3) is slightly less than in a £H 7 5 buffer (58-6), and the set is rather higher than that given by a 7-5 buffer in 132 minutes: 26-4 per cent, compared with 25-7 per cent. In the light of these results, it seemed desirable to define the optimum time of setting in steam at an excess pressure of 10lb./sq. in., and further experiments were therefore carried out in which fibres at 40 per cent, extension were set for 45> 75> 120 and 180 minutes before determining the extent of set and degree of damage. The results are given in Table VIII, which includes the data already given in Table VII.

T able* VIII

Time of Percentage set after setting 60 minutes’ release Damage (minutes) in boiling water (D) 30 25-9 62-7 45 26-9 60-3 60 26-4 58-3 75 27-5 59-6 90 28-8 60-8 120 30-5 61-4 180 30-0 67-9 From Fig. 6, where the degree of damage is shown as a function of the time of steaming, it is evident that the optimum time of setting stretched fibres in steam at an excess pressure of iolb./sq. in. is about 60 minutes. The preceding experiments with stretched fibres therefore indicate that the highest degree of set, consistent with minimum damage, may be obtained by treating the fibres with either (1) steam at an excess pressure of 10 lb./sq. in. for about 60 minutes or (2) a boiling buffer solution at pH 7 • 5 for 132 minutes. It must, however, be emphasised that the time of treatment is in each case highly critical; if longer times of setting are permitted, the damage sustained by the fibres is rapidly and severely accentuated, especially in the case of high temperature steam. Bearing this condition in mind, it seemed desirable to carry out further experiments on the setting of curled yarns, because this is an important process, and the optimum time of setting may vary with the nature and extent of the stress in the fibres.

THE SETTING OF CURLED YARNS (a) Material. A 4/6s yam, made from 6s quality mohair, was used throughout the experiments. The spinning twist was 5 turns/inch, and 2J turns/inch of twist were inserted in four-folding. (b) Procedure. A i-yard length of the yarn was knotted to form a loop which was then folded down to give a compact hank. After the latter had Strained Animal Fibres— Hind and Speakman T 29 been extracted with alcohol and ether to remove residual soap and oil, it was immersed in a large volume of the appropriate buffer solution for 18 hours at room temperature (usually 150 C.). The yarn was then formed into a double loop and introduced into the stainless steel apparatus shown in Fig.7. This consists essentially of a fixed lower clamp A and a movable upper clamp B, which slides up and down the two pillars of the instrument when the screw S is turned by means of the wheel W. The clamps were first adjusted so that their inner edges were exactly 15-0 cms. apart, and the looped yarn was then inserted in a longitudinal slot, about 1 mm. wide, cut in the lower half of clamp B. The upper half of the clamp was then screwed down by means of the two screws shown in Fig. 7, an effective grip on the yarn being given by a tongue of metal which fits exactly into the longitudinal slot in the lower half of the clamp in absence of yarn. With the apparatus in a vertical position, and the upper half of clamp A removed, the yarn was likewise introduced into the slot of the clamp while tensioned by means of a 5 g. weight. The upper half of clamp A was then screwed down, four 15-cm. lengths of 4/6s yarn being thus held between the jaws of the apparatus. At this stage, the wheel W was turned until the inner edges of clamps A and B were exactly 5-0 cms. apart. A short length of stainless steel rod, 3 mm. in diameter, was next inserted midway along the length of yarn, between the two pairs of four-fold yarns comprising the specimen under examination. Twenty turns were given to the rod, thus inserting 40 turns of twist into the yarn— 20 right-hand and 20 left-hand turns— by which means the length of the yarn was reduced to 5-0 cms. The curled yarn was then set for the desired length of time by immersing the lower end of the apparatus in a further supply of the buffer solution in which the yarn had been soaked for 18 hours, the solution being brought to the boil immediately before the yarn was introduced, and the volume maintained constant by a drip feed of distilled water during setting. Untwisting of the yarn was prevented by the short steel rod, which was so arranged that it rested against a stainless steel plate slipped between the two clamps of the apparatus. At. the end of the setting period, the apparatus was removed from the buffer solution and washed in three changes of cold distilled water. The steel rod was then with­ drawn from the yarn, leaving it free to uncurl when the apparatus was transferred to boiling distilled water. After relaxation had been allowed to proceed for 60 minutes, the apparatus was removed and allowed to cool before the hank was withdrawn for examination. Testing was carried out after the hank had been conditioned for at least 18 hours in an atmosphere at 65 per cent, relative humidity and 22-2° C. The number of twists retained by the relaxed hank was first determined by means of the apparatus shown in Fig 8.5 After the ends of the hank had been gripped by the fixed clamp A and the movable clamp B, with the clamps close together, a light pointer was inserted between the two pairs of threads at the point where twist had been inserted before setting. The num­ ber of revolutions made by the pointer as the movable clamp was caused to retreat from the fixed clamp was observed and doubled to give the number of twists retained by the relaxed hank. After the set of the curled yarn had thus been determined, the hank was removed from the apparatus and those parts which had been gripped in the setting instrument were cut away. The 16 threads thus obtained from each hank were then used for determinations of breaking load, 3-inch lengths being broken by means of the Baer single-thread testing instrument. As all experiments were carried out in duplicate,* each of the strength measurements recorded in Table IX is the mean of 32 observations, the average deviation from the mean being about -J of the recorded strength in all cases.

* Except one for 540 minutes at p H 7-Ó1. 3— The Optimum Conditions for Setting

Table IX

Time of Residual Breaking Time of Residual Breaking pH setting twists load pH setting twists load (minutes) (maximum (% of (minutes) (maximum (% = 40) untreated) = 40) untreated)]

304 15 5-5 69-8 7-01 15 11-8 56-7 30 9-8 70-0 30 23-8 560 60 13-3 62-3 60 27-5 52-8 120 20-8 55-4 120 33-3 52-0 240 30-8 52-0 180 34-0 60-9 360 35-3 46-2 360 33-5 58-6 540 31-0 54-0 403 15 ' 3-8 68-3 30 100 67-3 8-03 7 21-0 57-2 60 16-5 58-6 15 24-3 53-3 }20 24-5 58-9 30 28-5 52-7 180 28*8 64-0 60 30-4 54-7 300 34-3 53-5 90 32-8 54-4 360 33-8 53-9 120 35-3 53-0 180 OOOK.O O 56-6 502 15 4-8 61-9 270 33-5 50-4 30 110 55-1 360 33-5 48-3 60 22-8 61-2 120 26-0 59-9 9-26 7 19-8 46-0 180 34-8 59-8 15 24-5 53-7 270 34-8 57-3 30 28-5 54-1 360 35-0 57-9 60 33-5 54-5 480 31-5 543 90 35-0 54-3 120 350 57-8 603 15 11-3 59-2 180 34-3 50-0 30 19-8 53-1 270 33-8 39-5 60 24-3 58-1 360 32-4 29-6 120 30-8 58-5 180 33-5 58-8 10-03 7 12-8 55-8 360 33-8 56-6 15 24-5 59-3 30 28-3 51-6 60 31-5 53-4 120 32-8 37-2 180 32-8 34-0 270 330 29-3 360 30-3 18-1

The time at which maximum set is acquired at each pH value was read from the smooth curve showing the number of residual twists as a function of the time of setting, and the corresponding strength of the yam was given by the graph of breaking load against time of setting. None of these curves is reproduced but the resulting data are given in Table X.

Table X

Maximum set Time to acquire Breaking load pH (Residual maximum set (% of untreated) twists) (minutes)

3-04 35-5 > 360 > 46-5 4-03 34-7 324 54-3 5-00 35-3 279 58-1 6-03 34-5 240 58-0 7-01 34-1 210 620 8-02 35-4 150 55-3 9-26 35-0 120 54-1 1003 32-7 105 42-7 Strained Animal Fibres— Hind and Speakman

Determination of the optimum pH for setting twisted yarn is facilitated by the fact that, except at pH 10, the maximum set is practically independent of the pH of the setting medium. It is thus permissible to show the breaking load of the yarns as a function of the pH of the setting medium, and the resulting curve (Fig. 9) indicates that set yarns of maximum strength are given by a buffer solution at pH 6 • 7, approximately, the necessary time of boiling being about 220 minutes. In the case of stretched fibres, maximum set with minimum damage was obtained at pH 7-5, although generally good results were given by buffer solutions at pH values between 6 5 and 8 2. The fact that the optimum pH for setting twisted yarns is somewhat lower than that for stretched fibres is, no doubt, connected with the fact that the liquor: wool ratio is so much less with yarns than with fibres. When the liquor: wool ratio is small and the pH exceeds 7, the gradual accumulation of reaction products, such as sodium hydrosulphide, in the boiling liquor must have an adverse effect on the strength of the yarn. In trade practice, there­ fore, it seems clear that the optimum pH for setting yams and fabrics in boiling buffer solutions is the one defined by the preceding experiments with yarn, viz., pH 6 7 .

In the light of the preceding experiments with single fibres, it seemed desirable to examine the suitability of boiling water, steam and high tem­ perature steam as setting media for yarn, especially as the accumulation of reaction products in boiling buffer solutions at pH 7 and above seems to have an adverse effect on yarn set in such media. Unfortunately, no more of the original yarn was available, and the new yarn, though nominally the same as the original, was considerably weaker because it was made from a different type of mohair. For reference purposes, therefore, it was found necessary to determine the rate of setting of the new yarn and the damage it sustained in a boiling pH 7 buffer solution. The results are given in Table XI, which includes corresponding data for yarns set in boiling water, steam and high temperature steam. In these last three cases, the general procedure was the same as before, except that the yam was soaked in distilled water for 18 hours at room temperature, instead of in the buffer solution, before being introduced into the apparatus. T32 3— The Optimum Conditions for Setting

T able XI

Time of Residual twists Breaking load Setting medium setting (maximum = 40) (% of untreated) (minutes) pH 7 b u ffe r...... 15 130 66-3 30 20-0 60-7 60 27-5 55-5 120 33-5 63-4 165 34-8 69-3 210 34-5 71-3 285 34-5 68'3 360 33-3 65-3

Boiling water 30 11-5 45-4 60 21-3 56-0 120 27-0 620 180 31-3 64-8 300 35-5 69-6 480 35-5 66’5

Steam 30 16-5 49-9 60 24-0 56-1 120 310 67-1 180 320 70-7 240 350 69-3 360 35-8 60-4

High temperature steam—excess 15 - 250 51-6 pressure of 10 lb./sq. in. 30 300 54-2 45 32-5 59-1 60 34-3 611 90 350 67-9 120 36-8 69-3 150 37-0 66-9 180 35-0 60-5 240 36-8 54-8

The properties of yarns set in the four media for the times associated with maximum strength were deduced from curves illustrating the changes in set and strength with increasing time of setting, and the results are summar­ ised in Table X II. T ab le X II

Time of setting for Breaking load Setting medium maximum strength Residual twists (% of untreated) (minutes) J / pH 7 buffer ...... 210 34-5 71-4 Boiling water ... 320 35-5 68-4 Steam ... 186 330 70-8 High temperature steam 112 36-0 68-4

As regards set and strength, the differences between the yarns are small, and discrimination between the four methods of setting must be in terms of rate of setting and the rate at which strength decreases if the critical time of setting is exceeded. Just as in the case of single fibres, set is acquired most quickly in high temperature steam, but the maximum on the curve.showing yarn strength as a function of the time of setting is so sharply defined that Strained Animal Fibres— Hind and Speakman T 3 3 there would be grave danger, in practice, of weakening the yarn unduly unless the necessary time of setting were correctly defined and rigidly con­ trolled. Although the time of setting associated with maximum strength is less with steam than with the pH 7 buffer solution, the latter is superior in giving a higher rate of setting as well as a higher set and strength at the time associated with minimum damage. Finally, the rate at which yarns acquire a set in boiling water is so low that the pH 7 buffer solution must be regarded as the best of the four media for ordinary commercial use. In the light of earlier results, a pH 6-7 buffer solution would, in fact, be employed.

SUMMARY Although the chemical mechanism of permanent set is well understood, the conditions under which yarns and fabrics should be treated to obtain maximum set with minimum damage to the fibres have never been defined. Determinations of the rate of setting of stretched fibres in boiling buffer solu­ tions, boiling water, steam and high temperature ateam were therefore under­ taken, and the damage sustained by the fibres after various times of setting in the different media were also assessed. After the rapid primary breakdown of disulphide bonds, the degree of damage first decreases as linkage rebuilding takes place, and then increases as main chain attack supervenes. In the case of buffer solutions, the time associated with minimum damage decreases with rise of pH, but the lowest degree of damage is given by a buffer solution at pH 7 ■ 5 in 1^2 minutes, the corresponding set being 25-7 per cent, with fibres treated at 40 per cent, extension. As setting media, steam and boiling water are inferior to the buffer solution, for the times associated with minimum damage are greater, viz., 170 and 312 minutes, respectively, and the corresponding degrees of set are less, viz., 24 per cent, and 22 per cent., respectively. High tempera­ ture steam (excess pressure 10 lb. /sq. in.) is superior to the buffer solution in giving a higher degree of set (26-4 per cent.) in a shorter time (60 minutes) with slightly less damage. Similar results were obtained in experiments with curled mohair yarns, except that there was little to choose between the four setting media as regards the extent to which the yarns were set, and the damage they sustained in the critical times of setting. In the case of buffer solutions, the optimum pH was found to be somewhat lower (pH 6-7), and the critical time correspondingly longer, with yarn than with single fibres, presumably because of the lower ratio of solution to fibre, and the adverse effect of accumulating reaction products on the yarn when the pH exceeds 7. The critical times of setting in a boiling pH 7 buffer solution, boiling water, steam and high temperature steam were found to be 210, 320, 186 and 112 minutes, respectively. Although high temperature steam thus gives the best results with both single fibres and yarn, the maximum on the curve showing yarn strength as a function of the time of setting is so sharply defined that there would be grave danger of weakening the yarn unduly unless the necessary time of setting were correctly defined and rigidly controlled. It is unlikely, there­ fore, that high temperature steam will find extended use in practice for the setting of curled mohair yarns. A pH 7 buffer solution is superior to steam and boiling water in giving more rapid set, and although the critical time of setting is rather less with steam than with the buffer solution, the set given by the buffer is greater and the degree of damage less. A boiling pH 6-7 buffer solution seems, therefore, to be the best medium for setting curled mohair yarns in practice, but the critical time of setting must not be exceeded if the high degree of set associated with minimum da' >age is to be realised. T34 3— The Optimum, Conditions for Setting, etc.—Hind and Speakman

REFERENCES 1 Astbury and Woods. Phil. Trans. Roy. Soc., 1933, 232, 333. Speakman. Nature, 1933, 132, 930 ; J. Soc. Dyers &• Colourists, 1936, 52, 335. 2 Speakman and Stoves. J . Soc. Dyers <5- Colourists, 1937, 53, 236. 8 Busch. Ber., 1896, 29, 2127. Rosser and Ritter. J. Amer. Chew. Soc., 1937, 59, 2179. 4 Speakman. J. Soc. Dyers &■ Colourists, 1936, 52, 336. 6 Smith, quoted by Oliver. Proc. Roy. Soc., Edin., 1905-6, 26, 197.

ACKNOWLEDGMENT One of us (J.R.H.) is indebted to the Worshipful Company of Cloth- workers and to- the Textile Institute for scholarships which enabled him to take part in the investigation.

Textile Chemistry Laboratory. Leeds University. Received 6/8/44 FEBRUARY 1945 A53 THE JOURNAL OF THE TEXTILE INSTITUTE

1—FIBRES AND THEIR PRODUCTION

(B)—A n im a l “ More Profit in Open-face Ewes.” C. E. Terrill. Montana Wool Grower, 1944, 18, 13', 47 (through Biol. Abs., B , 1944, 18, 10815). Ewes with open faces weaned 12 per cent, more lambs than those with wool covering the entire face and 8 per cent, more than those with partially covered faces; they also pro­ duced 8• 6 more lb. of lamb per ewe year than ewes with covered faces and 4-4 more lb. of lamb than ewes with partially covered faces. They sheared about J lb. less grease wool than ewes with covered faces, but there was no difference between the groups in production of clean wool, length of staple or fleece fine­ ness at the side. W. Sheep Tick, Ixodes ricinus L .: Distribution in Northern England in Relation to Geology, Soil and Vegetation. A. Mijne. Parasitology, ^44, 35, 186-196. W. Colouring of Sheep. F. H. Brewitt. Farmer &■ Stockbreeder, 1944, 58, 1563. Coloured wool is subject to deductions in price because the resulting yarns are limited in their use. This lowering of the standard of British wool increases the threat from synthetic fibres. The use of bloom dips and powders has no intrinsic value, but is merely a device for enabling sheep to look well for sale and to appear a uniform lot. The use of such dips causes serious difficulties in processing and leads to depreciation in value of the wool. To stop their com­ petitive use among farmers it is suggested that legislation should be introduced to prohibit colouring matter in the manufacture, sale and use of dip or bloom, either in liquid or powder form. The use of normal dips is essential, and it is only the addition of colouring matter which causes manufacturing difficulties and thereby reduces the value of the wool. W. A Possible Gene Duplication in New Zealand Romney Shegp. F. W. Dry. N ature, 1944, 154, 552. W . (C)—V e g e t a b l e Ratooned S x P Cotton; Characteristics. R. H. Peebles and H. J. Fulton. U.S. Dept. Agric. Circ. No. 693, 1944, 11 pages. Seed cotton of ratooned S xP cotton, collected in 1941 from 33 fields in southern Arizona, differed significantly from comparable samples of the annual crop in the means of all measured characters, and in nearly all characters tended towards greater variability. On the other hand, the correlation between various characters was rather higher. The ratooned cotton had smaller bolls and fewer seeds, but these carried less fuzz and more lint. The fibre was slightly stronger and finer, but shorter and more prone to imperfections. The plants blossomed several weeks earlier than the annuals, thus developing the crop under different con­ ditions with respect to weather and insect pests. C. Cotton Plants: Testing Susceptibility to Wilt Disease. C. D. Sherbakoff, P. R. Miller and D. M. Simpson. Phytopathology, 1944, 34, 254-256 (through Rev. Appl. My col., 1944, 23, 340). The following simple and inexpensive pro­ cedure has given satisfactory results in field inoculation tests to determine the varietal reaction of cotton to Fusarium vasinfectum at the Tennessee Agricul­ tural Experiment Station. Hills of five seeds each were planted in silt loam soil on 22nd June, 1942, round wooden pegs, set about 4 in. deep in the ground. On 15th July the pegs were removed and the holes thus made filled with half a pint of liquid inoculum in the form of a synthetic nutrient solution on which the fungus had been grown at 800 F. The incidence of infection among the 23 varieties or strains tested ranged from o in the two resistant controls, Cook A54 i— Fibres and their Production 307 and Seabrook No. 10 (S.I.), to 52-5 per cent, in Trice x Tidewater (578), other highly susceptible sorts including Acala 911 (330-1-1-8), Coker 33-12 (289-3), C°ker 100 (994), Stoneville 5 (62), Half and Half (control), Coker' Wilds (176), and Acala 911 (330-1-8-4), with 51-9, 50, 44-4, 43-9, 41-7, 41-2 and 40-7 per cent., respectively, whilst artiong the more resistant were D.P.L. 11 (51), Coker wilt 100 (resistant control), Stoneville (37-13), Stoneville 37 x Stoneville 5, and Delfos 719 (992), with 5-7, 8-3, 12-0, 14-0, and 15-9 per cent., respectively. The performance of the control varieties in these trials closely approximated to the response expected on the basis of previous green­ house inoculation tests and common field observations. C. Boll Weevil and Cotton Aphid: Control. L. C. Fife. J. Econ. Entomology, 1944, 37, N o. 1, 19-21 (through Exp. Sta. Rec., 1944, 91, 315)- To meet a potential scarcity of arsenic, tests were conducted in Texas (1942) to deter­ mine the effects of reduced dosages of calcium arsenate and cryolite on the boll weevil and the cotton aphid. Two series of field plat tests were carried out, each consisting of four replicated randomized blocks; applications were made at 5-day intervals from July 3 to August 12 in series (1) and from July 20 to August 27 in series (2). In (1), significant increases in yield of seed cotton were obtained in plats treated with calcium arsenate alone or mixed with sul­ phur. The yield from treatment with cryolite or cryolite-sulphur mixtures was greater than in the control, but only in one case was it significant. In (2), the yields with calcium arsenate alone or in 1:1 mixture with sulphur were significantly better than for the control. It was doubted whether sulphur should be considered inert as it is somewhat effective against other insects such as pentatomids and mirids. »It is believed that a considerable part of the gain from some of the treatments was due to the control of a mirid, Creontiades signatus (Dist.). Yields were increased with cryolite and the 1:2-cryolite- sulphur mixture and significantly so by 1:3 cryolite; the 1: 1 mixture of basic copper arsenate and sulphur gave less increase than calcium arsenate or its 1: 1 mixture with sulphur. Only the plats treated with calcium arsenate or with its 1 :2 mixture with sulphur gave significant reductions in weevil infesta­ tion. Aphids never became abundant enough to cause appreciable injury. Except for the plats treated with the 1:5 calcium arsenate-sulphur mixture, dusting calcium arsenate or its mixtures with sulphur caused significant increases in the aphid population in (1). Cryolite or cryolite-sulphur mixtures were not followed by significant increases in aphid populations. C. Cotton Plant: Manuring in India. V. G. Panse. Indian Farming, 1944, 5, 131 -135 - A brief account is given of the results of an examination of available information on cotton manurial trials made in India. Nitrogen is essential for increasing the yield of cotton under both dry and irrigated conditions. Potash is without any value in all areas and phosphate shows no beneficial effect on yield over any large tract. There are, however, certain patches of soil where cotton responds to phosphate manuring. To the general increase in yield brought about by nitrogen the following two exceptions were observed: (1) In the irrigated tract, presence of soil salinity prevents the crop from responding to the fertilizer. (2) In rain-fed areas, manuring is not effective where rainfall is low. Different manures are compared, conditions for manuring are discussed, and the need for more trials is pointed out. C. Cotton Plant: Ammonia and Nitrate Nitrogen Nutrition. K. T. Holley and T. G. Dulin. Georgia Sta. Bui. 229, 1943, 54 pp. (through Exp. Sta. Rec., 1944, 90, 750). Comparison of ammonium sulphate and of nitrates as nitrogen sources for cotton made in water cultures showed that the early-maturing Stoneville No. 2 did not utilise ammonium salts so well as Durango cotton. Variety evidently should be considered in comparison of nitrogen sources. Studies in 1936-41 were concerned with the acid-base balance, reduced phosphate supply, reduced aeration, sugar concentrations, reduction of oxygen supply to roots, higher salt concentration in the fruiting period, leaf development, sodium chloride additions to solutions, boll-carrying capacity of plants, and additional trace elements. Even with improved space and volume relations no treatment up to 1941 had any marked effect in increasing fruiting of plants grown with ammonium sulphate as the nitrogen source. Factors directly concerned with photosynthetic efficiency of the leaf were considered as a possible fruitful field of investigation in relation to vigour and efficiency of the cotton plant. The i -—Fibres and their Production A55 results showed that cotton plants can make good vegetative growth and fruit fairly well at low phosphate concentrations when ammonium salts are the sole nitrogen source, and also that these salts can serve as the nitrogen source for cotton in water culture at relatively low salt concentrations. More evidence was provided to show that plants grown on nitrates as the nitrogen source contain more organic acid, but that the excess inorganic base is associated with more inorganic anions than with plants grown on ammonium sulphate media. There was some indication that excess of base over acids in cotton leaves tends to be similar with either nitrogen source. Studies in 1941 sug­ gested that trace element requirements of cotton vary with the nitrogen source and offered some confirmation of results of others with other species. C. Cotton Plant: Development in Egypt and the Sudan Gezira. F. Crowther. Ann. Botany, 1944, 8, 213-257. An account is given of observations on mor­ phological characters, production of dry matter, absorption of nitrogen, and yield, all recorded from replicated experiments, which furnish a comparison of the development of the cotton crop in the Suden Gezira and in the Nile Delta. The two areas, both irrigated from the Nile, are 1,200 miles apart. The Sudan crop is a winter one and the Egyptian a summer one. There were marked dif­ ferences in early growth which was rapid in the Sudan, but in Egypt retarded by low temperature. The growing season in Egypt, initially limited by low temperature, was also prematurely curtailed by bollworm infestation. In Egypt an early-maturing crop is achieved in part by the adoption of a spacing much closer than formerly and closer than that practised in the Sudan Gezira. Leaf growth was closely associated with rate of absorption of nitrogen, the relative leaf-growth rate in both countries being highly correlated with percentage of nitrogen in the leaf dry weight. Nitrogen absorption relative to plant size was more rapid during early growth in the Sudan than at any time in Egypt. Maturation of the bolls was delayed in the Sudan by low winter temperatures. The yield capacity of the Sudan Gezira crop, judged in terms of production per unit of either vegetative growth or nitrogen absorbed, was as efficient as or even more efficient than that of the crop in Egypt. Yield in the Sudan appeared to depend more upon soil factors than did yield in Egypt and to be closely related to nitrogen supply. C. Cotton Plant: Utilisation of Adsorbed Phosphate. R. Coleman. Soil Sci., 1942, 54, 237-246 (through Exp. Sta. Rec., 1943, 88, 453). Cotton and oats supplied with a nutrient solution, but with only that phosphate which had been adsorbed by the clay against acid and alkaline extracting solutions grew well on relatively small quantities of adsorbed phosphate whether it was held by the kaolinitic or the montmorillonitic clay, and the plants utilised a large percentage of the adsorbed phosphate present. Of the methods studied, Truog’s was the most effective in removing the readily available phosphate from the clays, but it failed to remove much phosphate that was available to the plants. C. Cotton Plant: Variety Tests in Mississippi Hill Station. J. F. O’Kelly. Miss. Farm Res., 1944, 7, No. 1, 7 and 8 (through Exp. Sta. Rec., 1944, 90, 750). Yields of lint per acre, acre value, lint percentage, staple length, and bolls per pound of lint are reported for cotton varieties tested at the station and three hill sub-stations for 1943 and during the period 1939-43. Results presented agree with those obtained in previous years. C. Mississippi Delta Soils: Fertilizer Needs for Cotton Growth. R. Kuykendall. Miss. Farm Res., 194a, 5, No. 11, p. 2 (through Exp. Sta. Rec., 1943, 88, 454). The most profitable rotation for obtaining maximum yields on soil types of the Yazoo-Mississippi Delta is winter legumes followed by cotton and fertilized with 20 lb. per acre of commercial nitrogen. C. Punjab-American 4F Cotton Plant: Effects of Manurial Factors and Water Supply on Growth. R. H. Dastur and M. Singh. Indian J. Agric. Sci., 1943, 13, 610-630. In extension of studies on the periodical partial failures of Punjab- American cotton, the results are fully reported of two field experiments of the multiple-factor type with 4F cotton on light sandy soils near Lyallpur. The first experiment deals with the main effects and interactions of N, P, K, and organic manures and water supply. In the second experiment, N was applied at two distinct periods and organic manure was omitted. The following con- A 5 ó i — Fibres and their Production elusions are drawn, (i) Nitrogenous manures have the greatest influence, both on meristematic activity, on extension growth, and on the proper maturation of the seed and lint. (2) Nitrogenous manure prolongs the functional activity of the plant and delays senescence, but it does not delay the onset of flowering, whether applied early or late. (3) Heavy watering slightly but significantly increases the internodal length of the stems, the boll size and the yield, but not the meristematic activity. (4) The benefit of N is enhanced by extra water. (5) Potash had scarcely any observable effects. (6) Phosphatic manure was beneficial only in the absence of organic manure and N. (7) High correlations were observed between yield and such characters as height, dry matter content, number of flowers and bolls, and boll weight. Records of plant development therefore afford fairly accurate guides to the ultimate effects of cultural treat­ ments on yield under comparable conditions. C. Upland Cotton: Effect of Removal of Squares on Yield. E . W . D u n n am , J. C. Clark and S. L. Calhoun. /. Econ. Ent., 1943, 36, 896-900 (through E x p . Sta. R ec., 1944, 90, 802-803). Experiments were conducted (1939-1941) at Stone- ville. Miss., to determine the effect on yield of removing at weekly intervals for various periods all squares large enough to attract boll weevils and of similarly removing given percentages of such squares. Recently-developed strains of Upland cotton tend to mature a large proportion of bolls from early-formed squares, and with this in mind an effort wa# made to obtain information for working out a dusting schedule for boll weevil control adapted to the fruiting habits of the early types of cotton grown in the Mississippi Delta. In these tests, hand removals at weekly intervals for 7-11 weeks of 10-50 per cent, of the squares, all resulted in reductions in yield. The greater square production which followed dusting with calcium arsenate in the absence of an appreciable number of boll weevils was not manifested in increased yields. C. Cotton Plant: Field Tests of Resistance to Fusarium Wilt. C. D. Sherbakoff, P. R. Miller and D. M. Simpson. Phytopathology, 1944, 34, 254-256 (through Exp. Sta. Rec., 1944, 90, 776). A liquid culture of F. vasinfectum w as suc­ cessfully used for inoculating cotton in the field, by pouring the inoculum into a hole in the centre of a hill. The cost of the culture medium is negligible, and very little time is required to prepare the inoculum and make the inoculations. A test of 23 cotton varieties ranging from highly resistant to very susceptible indicated that the method is a reliable measure of the resistance of cottons to F usarium w ilt. C. Cotton Seedlings: Testing Resistance to Angular Leaf Spot Disease. R. Weindling. Phytopathology, 1944, 34, 235-239 (through Exp. Sta. Rec., 1944, 90, 776). For testing the resistance of cotton seedlings to Phytomonas mal- vacearum , seeds are inoculated by immersing in bacterial suspensions for short and lengthy intervals. The seedlings obtained are then grown for 3 weeks at 27-350 C. In general, varietal reactions to the pathogen in these seedling tests have conformed with those in field plants. The method thus offers possibilities as a rapid supplementary test in breeding for resistance. For this purpose the method may be adapted to the material in hand by various modifications, such as the use of sand culture in place of the paper-towel technique here described. C. Boll Weevil and Cotton Aphid: Control with Calcium Arsenate. M. T. Young, G. L. Garrison and R. C. Gaines. /. Econ. Ent., 1943, 36, 901-903 (through Exp. Sta. Rec., 1944, 90, 803). Calcium arsenate treatments for boll weevil control are usually followed by an increase in cotton aphid populations, which may greatly reduce the yield and in certain cases lower the grade of the cotton. From the two experiments here reported, which were carried out in 1942 at Tallulah, La., in both of which the boll weevil infestation was light, it was indicated that poisoning with calcium arsenate may result in reduced yields unless an aphicide is also used. Comparisons are made of the arsenate alone and alternating and in combination with aphicides, as well as of the effects of applying at different times of the day. C. Cotton Jassid Insect: Occurrence in the Punjab. M. Afzal, D. N. Nanda and M. A bbas. Indian J. Agric. Sci., 1943, 13, 634-638. Three methods have been examined as the procedure in forming estimates of jassid infestation of test blocks of cotton plants in the Punjab; (1) sweeping up the adults with a hand net, (2) counting the living nymphs on 3-5 selected, average plants, and (3) i — Fibres and their Production A57 enclosing 3-5 plants in a fumigating chamber, and collecting and counting the dead insects on white paper. The report is mainly concerned with the statistical treatment of the data and Williams’s logarithmic transformation (1937) is adopted. The three counting procedures ranked cotton varieties in the same order and plant breeders are therefore recommended to use the sweeping method for the sake of simplicity. In tests of jassid-resistance, the Punjab-American strains 4F, LSS and 289F/43 were equally resistant and 289F/K25 the most susceptible. The desi Jubilee cotton was the most resistant strain. C. North Carolina Negro Cotton Farmers: Decline. North Carolina Sta. Rpt., 1942, pp. 77-78 and 81 (through Exp. Sta. Rec., 1944, 90, 846). Of a total decrease of 15,143 Negro tenant farmers in N. Carolina between 1930 and 1940, 11,696 occurred in the so-called cotton counties. Tobacco growing appears to have been a mainstay for many white tenants, but not for the Negro tenants. The conclusion is that conditions in the cotton market have been the most important factor in causing the exodus of Negro tenant farmers. C.

(D)—A r t i f i c i a l Poplar Wood: Suitability for Cellulose Preparation. G. Jayme, K. G. Hinden- burg, M. Harders-Steinhauser and F. Branscheid. Holz Roh-u. Werkstoff, 1943, 6, 1 -16 (through Chem. Zentr., 1943, ii, 283 and Chem. Abstr., 1944, 38, 4797s). Microscopic investigations are reported for a 10-year log (I) of Populus tremula villosa and a i-year sapling (II) of P. serotina. The sapling was 0 6-2-3 cm. thick, had a thin bark and a medullary portion 0-4-0-6 cm. in diameter. The cells were very thin-walled in contrast to thick-walled beech wood. Because of its morphological structure, poplar wood is suitable not only for chemical conversion, but also for paper pulp. The wood yields a much higher methyl alcohol-benzene extract than beech or spruce. The sapling wood (II) contains somewhat less pentosan, a little more lignin and about the same quantity of cellulose as 60-80-year beech. The older wood (I) contains considerably more pure cellulose than beech wood. In the sulphate process II gives a high yield of a strong pulp, with satisfactory bleaching properties. Barked II with the sulphite process yields a pulp with a very low a-cellulose content which is not suitable for chemical conversion and not very useful for paper; under the same conditions I gives a pulp with a satisfactory a-cellulose content, but with only moderate strength. The yield is better than with spruce, but the methyl alcohol-benzene extract is very high and the product is not suitable for rayon pulp without further purification. Beating gives a high yield of a pulp with a high a-cellulose content. However, the sulphite pulp does not have the strength of the sulphate pulp. C. “ Ardil ” Ground-nut Protein Fibre: Production. Imperial Chemical Indus­ tries Ltd. Textile Weekly, 1944, 34, 992. A brief announcement is made of the production from ground-nut protein, after experiments at Ardeer, of the cream-coloured, crimped, resilient fibre “ Ardil ” which has felting properties, dyes like wool, but is not attacked by moth. It is recommended for blending with wool and a fabric containing wool and "A rdil” in equal quantities is said to be scarcely distinguishable from 100 per cent. wool. C. Mixed Nylon and Cellulose or Protein Rayons: Production. Silk J. Rayon W orld, 1944, 21, October, 31-33. A review of patented processes in which one or other of the nylons is incorporated in spinning masses based on viscose, gelatin, zein, or soybean protein. C. Viscose: Degree of Ripeness; Determination. X. Herthe. Ind. textile, 1942, 59, 287 (through Chem. Zentr., 1943, i, 2552 and Chem. Abstr., 1944, 38, 47976). An apparatus for the determination of the ripeness of viscose according to the ammonium chloride method is described in which diluted viscose (20 g. viscose+ 30 c.c. water) is stirred with a glass stirrer. The addition of ammonium chloride is continued until the viscose no longer circulates with the rotating stirrer. C. Soybean Protein: Production. P. A. Belter, A. C. Beckel and A. K. Smith. Ind. Eng. Chem., 1944, 36, 799-803. A pilot-plant process for the production of soybean protein is described which comprises extraction of the protein from soybean flakes with water or dilute alkali, removal of suspended solids from the dispersion by the use of a gyrating screen followed by clarification in a centrifuge, precipitation of the protein by adjusting the p H to about 4-5 by i— Fibres and their Production (Patents) addition of acid, and settling, washing, filtering and drying the precipitate. The effects of variations in the conditions, particularly in p H , are discussed. A compąrison is made of alcohol-extracted and petroleum-ether-extracted flakes as raw materials for this process and the superiority of the alcohol-extracted material is pointed out. C. Strong Rayon and Staple Fibre: Production. E , W u rtz. Zellwolle u. Kunstseide, 1943, 1, 122-127 (through Chem. Abstr., 1944, 38, 50798). An illustrated description of the process involving the principle of the double coagulating bath, the second bath being higher in acid content and colder than the first. C. Viscose Rayon Manufacturing Wastes: Treatment. E. T. Roetman. W ater Works & Sewerage, 1944, 91, 265-268 (through Chem. Abstr., 1944, 38, 50799). After a description of manufacturing processes, wastes are divided into (1) caustic wastes from viscose formation, (2) acid wastes from regeneration and preliminary washing, (3) wastes from desulphurising and bleaching, and (4) miscellaneous wastes, including sanitary sewage and trash. Reclamation of spent alkali and acid is now considered as an integral part of viscose rayon manufacture. Dialysis removes 90 per cent, of the hemicellulose from used alkali solutions. Spent acid is reconditioned by filtration, evaporation of water and crystallisation of excess salts. C. P a t e n t s Polythene Threads: Production. British Nylon Spinners Ltd. and G. Loasby. B.P.565,282 of 10/3/1943:3/11/1944. Artificial threads, filaments and the like are produced by extruding molten polythene through a spinneret at a tem­ perature between 200° C. and 350° C. at a viscosity between 200 and 2000 poises, passing the extruded filaments into a chamber the upper end of which is vertically offset from the spinneret and through which a current of cooling gas is passed, and winding the cooled filaments on to a winding roll. The vertical offset is preferably of the order of ft. The chamber is preferably a vertical tube through which cooling air is passed upwardly and at whose upper end the air issues in a direction to avoid the face of the spinneret. It is pre­ ferred to cold-draw the filaments during the winding-up operation, for example, by means of feed rolls operating at different speeds. C. Fibre-forming Polyamides: Production. E. I. Du Pont de Nemours & Co. B.P.565,350 of 22/1/1943:7/11/1944 (Conv. 26/11/1941). A process for making fibre-forming interpolyamides of improved dyeing properties comprises heating a composition comprising 75-95 parts by weight of a mixture of equi- molecular proportions of hexamethylenediamine and adipic acid or an amide- forming derivative of either or both of these, or of a salt thereof, and 5-25 parts by weight of a mixture of equimolecular proportions of a diamine and a dicar- boxylic acid or an amide-forming derivative of either or both of these or of a salt thereof, the diamine and/or the dicarboxylic acid containing at least one oxygen atom in the chain separating its amide-forming groups, and continuing the heating until a fibre-forming product is obtained. Suitable diamines con­ taining oxygen atoms in the chain separating the amino groups are triglycol- diamine and tetraglycoldiamine. The interpolyamides produced by this method can be formed into strong orientated fibres which are markedly improved as compared to other diamine-dibasic acid polyamides in dye receptivity and which have high melting points (above 220° C.). Those obtained with the use of a diamine having at least two oxygen atoms in the chain separating the amino groups have, in addition to improved dye receptivity, improved level dyeing characteristics. C. Molten Filament-forming Compositions: Spinning. H. Dreyfus. B.P. 565,489 of 4/1/1943:14/11/1944. The composition is fed to the point from which it is extruded through a body of inert liquid maintained at a temperature sufficiently high to melt the composition. The liquid is preferably of lower density, so that the molten composition collects below the heating liquid and can readily be drawn off and extruded. The extrusion of the molten com­ position can readily be initiated by allowing the heating liquid to be extruded in the first instance and then changing over to the extrusion of the filament- forming composition. The extrusion operation can thus be started without difficulty notwithstanding a high degree of viscosity in the molten composition. 2— Conversion of Fibres into Finished Yarns A59

Suitable heating liquids include stearyl alcohol or other fatty alcohols contain­ ing at least 12 carbon atoms and aliphatic hydrocarbons containing a large number of carbon atoms. This method may be used for the spinning of syn­ thetic linear superpolyamides, polyvinyl compounds or cellulose derivatives. C. Rayon Spinning or Winding Machine Guide Funnel Bracket. American Vis­ cose Corporation. B.P.565,679 of 3/2/1943:22/11/1944 (Conv. 18/2/1942). A bracket for supporting a guide funnel of a machine for spinning or winding artificial threads comprises two separable elements, the upper of which supports the upper portion of the funnel, which funnel is capable of sliding in the lower element, and means connecting the two elements together for constraining their motion of separation to a straight line, so that the funnel is lifted by the upper of the separable elements and slides in the lower of the separable elements thereby moving in a straight line. C. Cellulose Esters: Production. British Celanese Ltd. B.P.565,812 of 20/1/1943:29/11/1944 (Conv. 20/1/1942). A process for the production of fatty acid esters of cellulose comprises pre-treating cellulosic material with a mixture of lower aliphatic acids, one of which is formic acid, containing a small proportion of a mineral acid catalyst, e.g. sulphuric acid, s nd then esteri- fying the pre-treated material by the addition in at least two si Ages of a fatty acid esterifying agent. The pre-treatment is preferably effected at a temperature between 16 and 50° C. for 30 to 100 min. C. Matt Cellulose Derivative or Polymer Fibres: Production. H. C. Olpin and S. A. Gibson (British Celanese Ltd.). B.P.565,815 of 22/2/1943:29/11/1944. In the production of fibres, films and like products by extruding a liquid com­ prising a fibre-forming polymer into a zone in which setting occurs, products of subdued lustre are obtained owing to the presence in the liquid of a water- insoluble condensation product of an aldehyde with an amino-triazine, e.g. a condensation product of formaldehyde and melamine. The fibre-forming polymer may be a cellulose ester or ether, polystyrene, a polyvinylidene derivative or similar polymer. Fibres having a subdued silk-like lustre may be produced by this method. The products can be dyed in fuller shades with a given quantity of dye and are less subject to deterioration under the influence of light than similar materials containing pigments such as titanium dioxide or barium sulphate. C. Rayon Staple Fibre: Cutting. American Viscose Corporation. B.P.565,841 of 13/4/1943:30/11/1944 (Conv. 15/8/1942). Staple fibres are produced by cutting a bundle of continuous filaments with a cutter which is made blunt to such an extent that it subjects the material to transverse compression along a substantial portion of its length during the cutting operation. The filaments should be in a somewhat softened or plastic condition. The resulting product comprises individual fibres at least some of which have a minor portion of their length in a crimped, barbed or corrugated condition or in a combination of these conditions. C. 2—CONVERSION OF FIBRES INTO FINISHED YARNS (A)—P r e p a r a t o r y P r o c e s s e s Card Fillet Reclothing Machine. Dronsfield Brothers Ltd. Textile Weekly, 1944, 34, 1000-1002. An illustrated description is given of a new i-h.p. driving unit mounted .on a hand trolley for use with the Dronsfield card fillet mounting machine. It serves to turn the cylinder at about i£ revs, per minute and is under push-button control by the man who nails down the fillet. C. (B)— S p i n n i n g a n d D o u b l in g “ Arunco ” Cop Skewer Holder. Arundel, Coulthard & Co. Ltd. T extile W eekly, 1944, 34, 914-915. An illustrated account is given of a simple device to prevent cops and skewers from jumping out of their holders, especially when the unwinding has reached the cop bottom. It consists of a bent steel wire attached at one end to the boss of the skewer holder and exerting resilient pressure against the skewer. C. Casablancas High-draft System: Application. J. Noguera. Textile Weekly, ■944> 34’ ę 1^ ^ 20’ 968-972, 1000-1018. A report of a lecture on the economy of space and labour that could be secured by adopting high drafting. Dis­ cussions by mill managers are reported. C. a 6 o 2— Conversion of Fibres into Finished Yarns

Cotton Spinning M ill: Reorganisation. Textile Recorder, 1944, 61, Ja n ., 36-42; Feb., 38-43; March, 38-42; April, 33-35; May, 38-42; June, 32-34; July, 45-48; August, 38-42. A continuation of a series of articles, the first four of which have already been noted. Part V reviews and classifies the auxiliary motions of the ring frame thus: Class (1) bunching, roving, building and tail­ ing motions; (2) automatic lubrication and scavenging motions; (3) lifting tap­ pets, extra twisting and compensating motions; (4) slubbing motion. Part VI deals with flyer frame processes and tabulates the machinery and labour required on ordinary and high-draft (Howard & Bullough) systems. Part VII reviews the twin-sliver and lap drawing systems. Part VIII discusses the importance of combing, and reviews recent developments in the machines. Part IX deals in the same way with carding. Parts X and XI describe modern blowroom systems and discuss problems created by increasing the density of cotton bales. Part XII deals with the dust problem and the single-process system of opening. Part XIII gives a summary of the main requirements for the modernisation of cotton spinning mills. C. Spinning Mule: Adjustment. Frank Scott. Textile Mercury (S' A rgus, 1944, in , 619-620. The writer explains the necessary calculations and the procedure to follow when changing a mule from the ‘ ‘ twisting ’ ’ to the ‘' striking through ” type. The twisting mule inserts only part of the twist in the yarn during the outward run of the carriage and the rest while the mule is "on the head ” . This is the usual practice for fine yarns of high quality. The " striking through ” mule inserts all the twist during the outward run and backing-off begins as soon as the carriage reaches the catch. This achieves greater pro­ duction and is suitable for coarse counts. The question whether to sacrifice quality for production has to be decided before changing the mule. In general, “ striking through ” is not employed for counts finer than 54s. C. Woollen Mules: Increasing Weft Yarn Production. G. Wakefield. T ext. W orld, 1944, 94, No. 6, 102-103. ■ Formulas are given for calculating the maximum mule output in terms of units of yarn length. From the data avail­ able in one particular mill, maximum production was obtained when ij-run (8 skein) weft yarn was spun. This result is confirmed graphically from a table showing the relation between average draws per min. and yarn counts. The same methods can be used for finding the count of warp to give the maximum yardage production. W.

P a t e n t s Spinning Machine Apron. J. Rockoff (Dayton, Ohio, U.S.A.). B.P.505,528 of 28/9/1942: 14/ 11/1944. An apron for a spinning or other textile machine has a fibre-contacting portion comprising a vulcanized resilient composition including, as an essential constituent, a synthetic rubber composed of butadiene acrylic nitrile co-polymer, and a vulcanizing agent, such as sulphur. The composition may also include a filler, a resin, dibenzyl ether and benzothiazyl disulphide. The apron develops substantially no static charge, is practically unaffected by oils and greases, and does not " eyebrow ”. C.

Flanged Yarn Packages: Ring Spinning. British Celanese Ltd. B.P.565,533 of 1/3/1943:15/11/1944 (Conv. 28/2/1942). A method of forming packages of yarn on flanged bobbins or spools by ring-spinning comprises traversing the yarn by means of a ring and traveller over a substantially constant length that is slightly shorter than the length of the spool or bobbin, and shifting the field of traverse to and fro along the length of the spool or bobbin with a fre­ quency that is lower than the frequency of traversing. In this way the winding of the package is continually varied between one traverse and the next so that the difference between the length of traverse and the length of the bobbin is systematically filled with yarn while at the same time small variations in the length of the spool or bobbin have little or no harmful effect since no traverse extends right to each end of the spool or bobbin. A ring spinning machine for carrying out this method is described. The method may be- applied to the packaging of yarns of any natural or synthetic fibres or filaments, but is particularly effective in the packaging of continuous-filament yarns having a smooth surface. It may be used in bobbin to bobbin twisting operations and in the collecting of artificial filaments continuously with their production. C. 3— Conversion of Yarns into Fabrics a 6 i

Yarn Package Covering Apparatus. American Viscose Corporation. B.P. 565,705 of 3/2/1943:23/11/1944 (Conv. 27/2/1942). Apparatus for applying a tubular cover to an annular package, particularly one of yarn or thread, comprises a main support bearing a package-supporting member that has a generally annular outer free portion against which the end of the package may bear, holding members projecting generally concentrically beyond an inner portion of the- package-supporting member to support the cover and a sleeve­ like member into which the package-supporting member can pass. C. Nylon-coated Spinning and Twisting Frame Ring. Clark Thread Co. (Newark, New Jersey, U.S.A.). B.P.565,796 of 31/5/1943:28/11/1944 (Conv. 18/5/1942). A ring for spinning and twisting frames consists of a metal core and a wearing surface of polyhexamethylene adipamide (nylon). C.

3—CONVERSION OF YARNS INTO FABRICS (C)— W e a v in g Cotton Weaving M ill: Reorganisation. G. A. Bennett. Textile Recorder, 1943, 61, May, 41, 42, 52; July, 35-38; September, 34-36; October, 32-34; December, 38-39; 1944, 61, January, 42-47; February, 44-47; 61; March, 43-45; April, 36-37; 1944, 62, May, 43-46; June, 36-42; July, 50-52, 66; September, 49-53; October, 49-54. A series of articles reviewing modern weaving machinery and accessories and their post-war development in the manufactur­ ing sections of the cotton industry. Part I discusses the structure of the industry; Part II covers the need for standardisation of cloth structures on the lines of the " utility ” fabrics and considers the prospects for automatic looms; Part III deals with the scope for cop-changing automatic looms as illustrated by the Northrop Model T loom, fitted with the Roper automatic let-off motion and the parallel underpick motion; Part IV reviews the chief types of shuttle- changing automatic looms; Part V describes the organisation and lay-out of a weaving shed, with notes on loom driving and the training of operatives; Part VI enumerates the chief technical improvements in automatic looms and weaving; Part VII reviews the utility of multiple-shuttle automatic looms. [Certain statements are challenged and revised in the June number, p 52]. Part VIII discusses the selection and preparation of yam for automatic weav­ ing. Part IX covers warp preparation and sizing for automatic weaving. Part X reviews developments in high-speed warping and winding. Part XI describes the Barber-Colman system of warp preparation. Part XII stresses the value of weft re-winding. Part XIII sums up the main requirements for post-war reorganisation. C. Automatic Shuttle-changing Rayon Loom. G. Hattersley & Sons Ltd. Silk J. Rayon World, 1944, 21, September, 28-32. A detailed, illustrated descrip­ tion is given of a new dobby loom for rayon and silk weaving fitted with auto­ matic shuttle-changing motion controlled by a set of tappets. C. Dobby Loom for Rayon and Silk. Wilson and Longbottom Ltd. Silk J. Rayon W orld, 1944, 21, July, 32-35. A detailed, illustrated description is given of a new dobby loom for rayon and silk weaving. C. Mechanical Warp Stop Motion. Mather & Platt Ltd. Silk J. Rayon World, 1944, 20, March, 34-37. A detailed, illustrated description is given of a mechanical warp stop motion of the drop bar type, with instructions for fitting it to a loom. C. Rayon Loom. Henry Livesey Ltd. Silk J . Rayon World, 1944, 21, O ctober, 44-45. The main features are described of a new loom for rayon and silk weaving which can be fitted with eight shafts to weave coloured stripes or w ith a 16-, 20- o r 24-shaft V -dobby. C. Rayon Loom Centre Weft Fork Motion. Silk J. Rayon World, 1944, 21, Juty, 30, 44. A detailed illustrated description is given of a centre weft fork motion for use with rayon and silk fabrics and its fitting and adjustment are explained. C. Rayon and Silk Looms. Butterworth and Dickenson Ltd. Silk J. Rayon W orld, 1944, 21, August, 34-39. Brief descriptions are given of the salient features of a 2 x 1 box loom and 2 x 1 pick-at-will loom for weaving rayon and silk. C. AÓ2 3— Conversion of Yarns into Fabrics (Patents)

Rayon Shuttles: Construction and Lining. Silk ]. Rayon World, 1944, 20, April, 28. Hints are given on the selection of shuttles for rayon weaving and the best types of shuttle brushes, tips, pegs and linings. C. Richmond’s Patent Shuttle Guard. John Williamson. Textile Mercury & A rgus, 1944, in , 644-645. Causes of " flying shuttles ” are discussed, the requirements of an effective shuttle guard are enumerated, and Richmond’s guard is said to have been approved by the Shuttle Guard Committee of the Home Office. A brief description is given of the working parts of this guard. C. Nylon Cloth: Weaving. Silk J. Rayon World, 1944, 20, M arch, 32-33. Advice is given on the weaving of nylon cloth, with special reference to the warp beam, the back rest, lining the shuttle, and the advantages of Lupton’s special temple. C. Rayon Fabrics: Weaving. J. H. Strong. Textile Mercury 6- Argus, 1944, in , 617-8, 621, 663, 665, 668. Practical advice is given on the choice of healds, temples and let-off motions, the spacing of looms, gaiting the warp, and selvedge formation. C. Indian Woods for Shuttles and Bobbins. M. A. Rehman. Indian Forest B u lletin s, N os. 121 an d 122 (1943) (through N a tu re, 1944, 154, 699). The search for substitutes for foreign timbers for use in the Indian textile industries has shown that the light-coloured sapwood of Diospyros melanoxylon or ebony is the best alternative to cornel or persimmon for shuttles, though it has only half their useful life. Four native woods are finding extensive use instead of beech, birch and maple for bobbins. C. Loom Reeds: Maintenance. H. E. Wenricli. Rayon Textile Monthly, 1944, 25, 385-386. Practical hints are given on the avoidance of trouble due to rusty and broken reeds and on the repair of reeds. C. “ Plasti-weld ” Automatic Loom Bobbin. American Paper Tube Co. R ayon Textile Monthly, 1944, 25, 383-384. An illustrated description is given of a bobbin with laminated paper tube welded in a steel mould to a plastics head, to which, in turn, is welded a hardened steel casing with three ribs resembling the three rings on familiar bobbins. In effect, barrel, head and rings form one integral unit. The barrel withstands the crushing that occurs when highly twisted yams (particularly nylon) are steamed. Ć. Idle Looms: Adjustment to Prevent Weak Places in Cotton Fabrics. F. Kendall. /. Textile Inst., 1944, 35, T117-T122. C. (D)— K n it t in g Knitting Machine: Development. J. B. Lancashire. Silk J. Rayon World, 1944, 21, O ctober, 46-48, 33. The author offers a forecast of technical advances in the post-war knitting industry, based on notes of new machines and developments in the combination of various stitches. C. Knitting Structure: Influence on Shrinkage and Finishing of Hosiery Fabrics. See Section 4 (K) page A68. W. (G)—F a b r i c s Casein Fibre and ‘'Fibro” Mixture Fabrics: Construction. M essrs. Courtaulds Ltd. Silk J. Rayon World, 1944, 20, April, 26-27. Illustrations are given of stripe and check effects based on the different affinities for dyes of spun rayon derived from casein and from viscose. Spun casein rayon enhances the lustre and silkiness of wool materials, but woollens containing spun casein rayon contract more from the width in the loom. They should be woven 5-10 per cent, wider to allow for this. When a yam containing both casein and Viscose rayon is burnt, the viscose component vanishes, but the casein leaves a " ghost ” thread of black, like loaded silk. C.

P a t e n t s Knitting Machine Hydraulic Coupling. William Cotton Ltd., G. Wilders and J. E. Lynam. B.P.565,240, 565,268 of 9/11/1942:2/11/1944. (1) A Cotton’s Patent or other knitting machine of the type having a member mov­ able to and fro along a line of needles is provided with an hydraulic coupling, movable to and fro, for connecting the member to driving means, which coupling comprises an hydraulic chamber and a piston member relatively 3—Conversion of Yarns into Fabrics (Patents) A63

movable to and fro in the chamber, of which two parts of the coupling one is connected to the member and the other to the driving means, a by-pass con­ duit for establishing connection between opposite ends of the chamber so that hydraulic fluid may flow from either side of the piston member to the other, and a valve for opening and closing the conduit, and with valve-operating means for opening the valve at or before (e.g. near) the end of the traverse of the member in either direction and for closing it at or after (e.g. shortly after) the commencement of the traverse in the reverse direction. This coupling may take the place of the usual friction box. (2) A knitting machine of the type ■specified has hydraulic m echanism for driv in g th e m em ber, and m eans con­ trolling the mechanism so as to vary the length of travel of the member auto­ matically as knitting proceeds. The knitting machine includes a member movable to and fro along a line of knitting instruments, hydraulic mechanism for driving the member, valve means controlling the hydraulic flow, and auto­ matically adjustable valve-operating means for controlling the operation of the hydraulic mechanism to vary the length of travel of the member. In the application of the invention to a Cotton’s Patent or other straight-bar knitting machine, the hydraulic mechanism may be driven by the Coulićr mechanism. The movable member may be a carrier or carrier rod, in which case there may be adjustable stops for variably determining the length of traverse of the carrier or rod, and valve-operating means or controlling means controlling the hydraulic mechanism, adjustable with the stops to correlate the hydraulic drive with the permitted length of travel of the carrier or rod. Conveniently, there are spaced valve-operating means or controlling means, and connections for racking them inwards or outwards as the stops are racked. C. Machine Knitting Needle. F.N.F. Ltd. and R. Peel. B.P.565,357 of 1/3/1943: 7 /11 /1944. A machine knitting needle comprises a member providing a tubular guide for a tongue and formed at one end with a bevelled portion terminating in an integral extension, and a strip permanently secured along the tubular member and along the extension thereof, the extension and the adjacent portion of the strip being formed into the shape of a hook. Thus the •extension extends along the portion of the strip on which the hook is formed, so that the yarn, as it slides from the hook and along the bevelled portion of the needle, does not pass over any transverse joint between the strip and the tubular member and, therefore, runs no risk of being torn or frayed. C. Patterned Fabrics: Knitting. Hemphill Co. B.P.565,497 of 17/2/1943: 14 / 11 /1944 (Conv. 18/2/ 1942). A method of knitting in an independent needle knitting machine comprises the steps of forming adjacent and figured areas of a fabric from plain stitches of appreciably'different lengths and causing stitches at the border and adjacent portions of the said areas to be robbed or redistri­ buted so as to cause a blending or merging of one area into another such adjacent and figured areas being positioned selectively at any desired location crosswise of the fabric. Stitches in some of the patterned areas may be drawn relatively tight, whilst other areas may be formed from stitches which are drawn loosely. Wrap loops may be superimposed upon the patterned areas. For this method of knitting there is provided an independent needle knitting machine (e.g. a circular knitting machine) having needles and sinkers, wherein all the sinkers are formed with two stitch drawing levels over which needles may measure and draw loops and wherein means are provided for selectively separat­ ing the sinkers into different pathways according to a pattern so that loops may be drawn over either of the stitch drawing levels as desired, whereby adjacent and figured areas are positively selected at any desired location crosswise of the fabric. The sinker levels may be so arranged that in drawing stitches over them relatively tight loops are formed over one level while loose loops are drawn over the other level. Casting off means may be provided, including cam means adapted to move some sinkers inwardly to one extent to cast off one type of loop, and other sinkers in to a greater extent for casting off the other type of loop. Wrap striping means may be provided. C. Patterned Fabric: Production. Prospect Manufacturing Co. Ltd. B.P.565,535 of 8/3/ 1943: 15/11/1944. A stripe or check pattern effect, or an effect similar to wood graining, is produced on one or both faces of a fabric by the use of a combination of yarns of low (5-6 t.p.i.) and abnormally low (1-5-3 t.p.i.) turns to give a contrasting pattern or shade effect. Ply yarns may be used and may AÓ4 3— Conversion oj Yarns into Fabrics (Patents) be made up of differently coloured yarns so that the da6ign or effect is woven in colour. Alternatively, ply yams may be used which have different dyeing characteristics. The yams may be either S or Z twist or both in combination. The order in which they are woven may be varied to produce any desired contrasting patterns or colour effects. C. Nylon Warp Sizing Apparatus. J. C. E. Bessieres (Nelson, Lanęs.). B.P. 565,570 of 12/1 / 1943: 16/11/1944. Apparatus for sizing yam as it passes from the creel to the beam of a sectional warping machine comprises a trough to con­ tain the size, a roller over which the yam passes rotating within the trough, the roller being driven from the warping machine so that its speed is auto­ matically controlled by that of the beam of the warping machine, a reed behind the sizing roller, a second reed between the sizing roller and the beam of the warping machine and means, preferably heated gas or air, for drying the yam after it has been sized. The use of this apparatus is particularly advantageous for the sizing of nylon yams. C. Ball or Reel Winding Machine. L. Towsk (Melbourne, Australia). B.P. 565,622 of 5/9/1940:20/11/1944. A machine of the type comprising a rota­ table mandrel vertically disposed and a coacting off-set winding arm mounted and arranged for rotation around the vertical mandrel, the axis of the winding arm being disposed in the same plane as, but obliquely to, the axis of the mandrel in order to direct and wind the yarn on to the mandrel, is character­ ised in that the speed of rotation of the winding arm is variable relatively to the speed of the mandrel so as to obtain a required pattern of ball or reel. C. Stocking Toe Tip: Knitting. C. A. Kaufman (New York). B.P.565,625 of 3/11/1942:20/11/1944 (Conv. 19/2/1942). The tip portion of a fully fashioned flat-knitted stocking toe blank is produced by knitting a portion at the tip which is tapered at a rate greater than the conventional rate used to provide a tip capable of being closed by a looping operation thereby causing the fabric to come rapidly to a point. Tapering portions may be knitted along the selvedges of the blank and a tapering portion therebetween, with the three portions tapering to a common point. The edge of the tip may be defined entirely by accelerated tapering of portions of the outermost selvedged wales of the blank, adapted to bring the wales rapidly to a point and to give a relatively blunt end to the tip. With this type of tip the usual looping operation is eliminated and the closing operation comprises only the single operation of seaming. C. Weft Beat-up Mechanism. D. W. Shimwell. B.P.565,635 of 26/2/1943: 20/11/ 1944. In a beat-up mechanism which allows of the acceleration cf the loom cycle without increasing the speed of the shuttle through the shed and without the necessity of altering the shuttle race or track, a beating-up comb which is separate from the reed enters the warp threads adjacent to the reed from above, travels to the beat-up point and then withdraws with an upward movement from the warp threads and returns to its entry point in order to perform the next beat-up operation. C. Knitting Machine Latch Opening Member. Mellor Bromley & Co. Ltd. and A. Shortland. B.P.565,704 of 25/1/1943:23/11/1944. A latch opening mem­ ber is formed with an operative portion so shaped that it can be interposed between the hooks and the closed latches of needles in a knocking-over plane so as to oppose the needles in a direction transversely to their lengths, whereby, as the result of the shaping and the relative movement between the needles and the member in a course-wise direction, closed latches are opened after knocking-over has occurred. The latch opening member may consist of a relatively thin cam formation, such as a finger or prong curved so that it acts upon the inner edges of the latches, and may be inherently resilient or spring- controlled. C. Knitting Machine Patterning Mechanism. Mellor Bromley & Co. Ltd. and A. Shortland. B.P.565,722 of 27/1/1943:24/11/1944. In a patterning mechanism, selecting cams or levers are provided which are bent or cranked to various degrees respectively, so that when they are assembled in a series or bank the bent or cranked portions are convergent and the spacing of the operative ends corresponds with the spacing of the butt positions, whilst the portions of the cams or levers which are directly acted upon by, the projections 4— Chemical and Finishing Processes A 65 on the rotary unit are spaced wider apart thereby enabling the spacing of the projections in the axial direction to be correspondingly increased. For racking the patterning unit there is provided a pawl and ratchet mechanism wherein the pitch of the teeth is a multiple of the circumferential pitch of the holes or grooves in the unit, and a number of pawls are arranged suchwise as to enable them to operate successively for imparting successive racking movements to the unit. The patterning unit comprises a sleeve adapted to receive pins, pegs or strips and rotatably mounted on a central hub or boss in connection with a friction device, whereby, while racking of the sleeve is permitted, free rotation and consequently over-running of the sleeve is prevented. C. Yarn Beam. F. S. Hodgson. B.P.565,733 of 15/3/1943:24/11/1944. A beam for silk, cotton or other yarn comprises a hollow metal barrel with aligned diametrically opposed holes towards opposite ends, and two flanges, each of which is rigid with an externally threaded collar which is a sliding fit upon the barrel, the collar threading into an internally threaded divided portion of a collar having a solid or undivided portion with aligned holes from opposite ' sides, means for closing the divided portion of the external collar upon the internal collar, and a pin adapted to pass through the undivided portion of the external collar and the barrel from side to side of the collar to secure the collar and so the flange to the barrel. C. Warp Knitted Fabric: Production. Daybrook Fabrics Ltd. and R. R. H. Gittel. B.P.565,754 of 24/3/1943:27/11 /1944. A warp knitted fabric which has substantially the same degree of stretch or extensibility in all directions consists of two sets of warps and is produced on a machine that utilises one needle bar and two guide bars, each guide bar being threaded to every second needle and the two guide bars supplying alternate needles. One guide bar is given a number of motions wherein each guide wraps its thread in alternate courses first round one and then round the other of two successive needles, is then displaced so as to wrap around one of these needles and an adjacent needle and is then returned so as to be ready to repeat this cycle. The other guide bar is simultaneously given a number of motions in which each guide wraps its thread in alternate courses first round one and then round the other of the needles, in two successive pairs thereof, that in these courses is not supplied by the first guide bar, is then displaced so that the aforesaid adjacent needle is included in the two successive pairs, and is then returned so as to be ready to repeat this cycle. C. Machine Knitting Needle. F.N.F. Ltd., G. L. Bolden and R. Peel. B.P. 565.755 of 30/3/1943:27/11/1944. A machine knitting needle has a tubular shank, the whole of one end of which is swaged to form a pin bent to the shape of a hook, the pin being offset to one side of the shank and an opening being formed in the other side for the passage of a tongue which alternately overlaps the needle hook and is withdrawn into the shank. Accordingly, the main body of the hook is of tubular rather than solid cross-section, although in the swaging operation the bore of the tube in relation to its wall thickness is very greatly reduced. C. 4—CHEMICAL AND FINISHING PROCESSES (A)—P r e p a r a t o r y P r o c e s s e s “ Superbiolase ” : Application in Desizing. A. V. Surovaya. Tekstil. Prom., 1944, 4, No. 4, 14-18 (through Chem. Abstr., 1944, 38, 50872). Superbiolase is an enzyme preparation obtained by growing Actinomyces diastaticus on a potato decoction. At 70-100° superbiolase renders starch soluble and then con­ verts it into dextrins. Saccharification of the dextrin is considerably slower. Because of these properties, superbiolase is valuable for use in desizing, where it is much more active than malt diastase. It is of value also in the preparation of size and finishing materials. The desizing properties of superbiolase as affected by concentration, temperature, time and p H were studied. Satis­ factory results were obtained by (a) steeping a dry fabric in a bath containing 1-2 g. per 1. of superbiolase at 80-85° f°r 2-3 min., then rinsing with water at 60°, (b) steeping in a bath of approximately 5 g. per 1. at the same tem­ perature for 30-35 sec., then rinsing with water at 70°, or after 15-30 min. rinsing with hot and cold water, (c) soaking the fabric in water at 75-80°, after 15-30 min. steeping in a superbiolase solution of 3 g. per 1., and finishing a 6 6 4— Chemical and, Finishing Processes as in (b ). Superbiolase is most active at p H 6 -6 -6 -y. Usually, acidic impurities accumulate in a desizing bath. The effectiveness of a bath is readily restored if these impurities are neutralised, e.g. by adding lime. Methods for desizing cotton fabrics with superbiolase in various types of apparatus are given. C.

(B)— B o i l i n g , S c o u r in g , D e g u m m in g a n d W a s h in g Rayon Fabrics: Scouring and Bleaching. Silk J. Rayon World, 1944, 21, July, 40-44. A broad outline of the scouring, desizing, and bleaching of cellulosic rayon and nylon fabrics, including knitted materials. C. Silk: Degumming. Silk J. Rayon World, 1944, 21, June, 34-38; August, 30-32. A review of recent publications on the chemistry of the degumming process, single and double bath methods, and special considerations in the treatment of silk fabrics. C. Fine Worsteds: Scouring. G. L. Atkinson. Text. Merc., 1944, ill, 536-537, 539. In processing bright-coloured fine worsteds, e.g. with white ground shades, cold scouring avoids colour bleeding, but results in a thin, papery handle. The dolly gives a better scour than the open-width machine. There is no colour loss or felting, and a satisfactory handle is obtained, if the pieces are thoroughly wet out in aired or warm water, the dolly run dry, and then the alkali (3-40 Tw.) added. Both alkali and soap should be entered at hand heat, preferably with the machine in motion. After scouring for J hr., washing out is done for at least 1 hr. (for pieces of approx. 50 lb. greasy weight), cold water being used for at least half the washing out time, and the final temperature not exceeding ioo° F. Sodium hexametaphosphate is used to clear any residual lime or calcium soaps. W. Detergents in the Wool Industry. M. Lipson. Text. J. Australia, 1944, 19, 117-120. The fundamental factors involved in detergency are discussed with relation to wool scouring generally, as follows:—Wetting and wetting tests; removal of wax, fat, oil or grease; removal of dirt; removal of water-soluble material in solution; stability of the detergent solution. Various types of sul- phated fatty alcohols are briefly described. Whatever alkali is added to the scouring bath, the p H value should be kept to the optimum of approx. 10. Experiments are described on the introduction of p H control in raw wool scour­ ing and in backwashing dyed tops, and on a comparison between a sulphated fatty alcohol scour and a soap-soda ash scour in the removal of a combing oil. W. (I)—D y e in g Cellulose Acetate Rayon: Processing. Silk J. Rayon World, 1943, 21, June, 21-22; July, 24-26. The writer reviews recent developments in the processing of acetate rayon. Part 1 deals with dyes of the azo-thiazole type, brown azo dyes derived from xylidine, and non-phototropic yellow dyes. Part 2 gives hints on the prevention and correction of creases. C. Dyed Acetate Rayon: Fastness to Light. G. zum Tobel. Zellwolle u. Kunstseide, 1943, 1, 13-16 (through Chem. Abstr., 1944, 38, 48089). D yes on mat acetate rayon which had been treated for light protection had about twice the resistance to light as compared with untreated rayon. The impregnations do not affect an intrinsic fastness in the dyes. With prolonged exposure to light the strength of the mat rayon is decreased, the more effective the fast­ ness and the darker the dye the smaller the decrease. No marked differences in fastness were found in the ten dyes tested. With the exception of the lightest dye, which was bleached during exposure, all other dyes turned reddish. C. Knitted Cotton Goods: Cold Dyeing. N. A. Vtorova. Legkaya Prom., 1944, 4, No. 1/2, 13-14 (through Chem. Abstr., 1944, 38, 4806”). Plant-scale experi­ ments are described on dyeing knitted cotton goods in cold baths with direct dyes. Satisfactory results were obtained by adding to approximately 2 cu. m. of tap water 5 g. per 1. of neutralised and diluted 1:2“ Kontakt,” then 500 g. of the dye dissolved in hot water, skimming off the surface fat, introducing 50-60 kg. of cotton, removing after 20-30 min., squeezing, rinsing, centrifuging and drying. After 5 or 6 batches of cotton have been dyed replace the cold water to the original level, add 50 per cent, (of the original amount) of wetting agent and 300 g. of dissolved dye. This cycle may be continued for 2 weeks or more; when spots appear on the dyed goods, drain the tub and start anew. C. 4— Chemical and Finishing Processes

Nylon Yarn: Colouration. Silk J. Rayon World, 1943, 20, No. 232, 34-37, 27; No. 233, 31-34; No. 234, 28-32; 1944, No. 238, 38-41; No. 240, 39-40; No. 241, 39-41; No. 242, 36-38; No. 243, 42-47. The production of nylon is briefly reviewed, physical properties of the filaments and yams are summarised, and directions are given for colouring nylon yams with (1) acetate rayon, (2) acid, (3) chrom e, (4) v a t, (5) basic, (6) azoic, an d (7) d irect dyes. C.

Silk: Dyeing Black. F. Jordinson. Silk J. Rayon World, 1944, 20, March, 42-45. Practical hints are given on the dyeing of silk by acid, direct, sulphur, azoic and logwood blacks. C. Viscose Rayon Yarn Cakes: Dyeing. C. C. Wilcock. Textile Recorder, 1944, 62, October, 74-79; Silk J. Rayon World, 1944, 20, October, 49-55. Advice is given on the dyeing of viscose yarn in cake form, with particulars of the degree of exhaustion of various dyes, and suitable recipes. C.

Dye Solution Concentration Recording Device. T. B. Davenport. /. Sci. Instruments, 1944, 21, 188. In order to make the apparatus described pre­ viously more suitable for use by unskilled operators, alterations have been made in the circuit. The logarithmic stage and the three straight resistance capacity coupled stages remain the same, but a balanced peak reading valve voltmeter circuit is substituted for the diode. A moving coil meter reading 100/iA full- scale deflection is used in place of the galvanometer previously employed. C. Knitted Goods: Dyeing with Vat Dyes. S. A. Melikhov. Legkaya Prom., 1942, 2, No. 5/6, 26-31 (through Chem. Abstr., 1944, 38, 5085’). A study was made of the effects of temperature and duration of dyeing, of auxiliary chemicals and of the conditions of preparation of the vat on the quantity of dye (Chl^oindanthrene Blue) absorbed. Absorption was determined by dis­ solving o-2 gm. of dyed material in 100 gm. of sulphuric acid (d. 1-84), trans­ ferring to a beaker containing 20-30 ml. of a 1 per cent, gelatin solution in 375 ml. of water, and comparing the colour of the mixture with that of dye solutions of known concentration. Before dyeing, the dye should be com­ pletely reduced and the fabric should be steeped in a sodium hydrosulphite solution. The optimum temperature is 40-50°. Raising the temperature to 80-85° docs not increase the quantity of dye absorbed, and causes smears. It is preferable to boil the fabric before dyeing. Gradual addition of sodium hydrosulphite during the dyeing has no effect. Soaping after dyeing is required to produce a good colour. C. Dyeing Bright Shades on Woollen Military Rags. D yer, 1944, 92, 215-216, 253-254, 297, 299. Woollen rags from khaki and air force blue uniforms felt considerably during carbonising, stripping and re-dyeing, thus increasing the difficulty of achieving good penetration. Felting during carbonising with gaseous hydrochloric acid can be decreased by thorough preliminary drying of the rags, by curtailing the period of rotation, by controlling the speed of rotation by means of a variable speed gear, and by thorough neutralisation of residual hydrochloric acid. An effective neutralisation method consists in steep­ ing the rags throughout the day in cold water, which is changed every 2 hr., then steeping overnight in strong soda ash solution (30 lb. soda ash per 1,000 lb. of rags), and finally rinsing cold. Milk of lime penetrates thick, firmly milled rags better than does soda ash, but careful preparation and application are necessary. Stripping by a multi-bath process is described, including the use of hydrosulphite compounds, e.g. Formosul C and Erasol C for khaki, and Zinc Formosul for air force blue rags. Various acid and chrome colours are recommended for re-dyeing, precautions to be observed in their application being noted. The question of the use of bichrome is discussed. W. Levelling in Wool Dyeing. T. C. Hutchins. Amer. Dyes. Rep., 1943, 32, 571-2, 583-4. The influence is discussed of preparing and dyeing processes on the level dyeing of wool. Uneven chlorination may cause unlevel dyeing, but the main factor may be the increased dye affinity conferred by chlorination. The methods suggested by Trotman (these A b s., 1933, A 371) and Trotman and Bell (/. Soc. Chem. Ind., 1935, 54, 29 T) for controlling dye absorption by chlorinated wool are described. Uneven distribution of acid from carbonising may cause unlevel dyeing; according to Brandy and Burnham (these A b s., 1934, a 6 8 4— Chemical and Finishing Processes

A 492) dry carbonising obviates this difficulty. If unevenness of the acid con­ tent exists or is suspected, it may be levelled by thorough washing of the material for extended periods in almost boiling water, with or without Glauber's salt. Thorough washing and rinsing are necessary in every process, and the installation is recommended of washing systems which are both efficient and speedy. The functions of levelling agents are discussed, and a brief note given on touching-up. W. (J)— P r i n t i n g Chrome Mordant Screen Prints: Production. Rayon Textile Monthly, 1944, 25, 387-389. Practical hints are given on the use of chrome mordant colours in screen prints, with special reference to off-shade, “ measly ” and stripe defects. C. (K)— F i n i s h i n g Plastics: Use in the Textile Industry. H. Jones. /. Soc. Dyers &• Col., 1944, 60, 225-232. Variation of the properties of plastics by co-polymerisation, plasticisation, and the use of catalysts and accelerators, fillers and lubricants is discussed. Polymerisation and condensation are considered in relation to textile uses and the reactivities of resins as chemical components are briefly discussed. The use of cellulose and cellulose derivatives, casein, polyamides, polyesters, Vinyon, Saran, polystyrene, and thermosetting resins for the pro­ duction of fibres, and the uses of plastics as bonding agents for films, fabrics and pigments, and as finishing agents and coating materials are reviewed and future lines of development are indicated. C. Camauba W ax: Production and Uses. N. S. Knaggs. Chem. and Eng. N ew s, 1944, 22, 1564-1569. Carnauba wax occurs as a protective coating on the fronds of the carnauba palm which grows in north-eastern Brazil. The fronds are dried, shredded and beaten to loosen the wax, which is therucollected and refined. The wax is melted in kettles, poured into moulds, aSowed to solidify, broken up into blocks and bagged for export. Brazilian refining con­ sists in melting and forcing through coarse cloth with the aid of wheel presses. In the United States the wax is refined by melting, mixing with certain filter aids, and then forcing through steam-heated filter presses. Flake wax is pro­ duced by running the molten refined wax over metal drums in thin layers, allowing it to solidify, and scraping it off with a doctor blade. Carnauba wax is used in the production of carbon paper, in printing inks, floor and shoe polishes, cosmetics, ointments and many other products. A high-grade paper has been made from fronds from which the wax has been removed. The pith of the tree has a high starch content. The wood is extremely hard and is impervious to insects and sea water. C. Starch Adhesives: Development and Uses. L. T. Smith and R. M. Hamilton. Chem. and Eng. Newts, 1942, 22, 1482-1484, 1494-1496. The development and uses of starch, adhesives are reviewed and theories of adhesion are discussed. Various modifying agents and plasticizers used in starch adhesives are men­ tioned. Differences in properties between the various starches and dextrins are discussed. An extensive bibliography is given. C. Cottage Steamer: Use and Mechanism. D yer, 1944, 92, 293-395, 305, 335-336, 381. The cottage steamer has a wide field of use, e.g. for shade development and fixation of the dye in printing fabrics and dyeing yarns, for enhancing the natural lustre and resilience of pile fabrics, and for increasing the dye affinity of animal fibres. Suggestions are made for attaining the following essentials on which successful pressure steaming depends: uniform action of the steam; avoidance of the use of over-moist steam, or steam containing a considerable amount of random condensate water; loading the goods in a dry and clean state, and protecting them from flying spray and condensate water. Details are given of the selection of pressures for different types of goods. W. Knitting Structure: Influence on Shrinkage and Finishing of Hosiery Fabrics. W. A. Dutton. J. Soc. Dyers &■ Col., 1944, 60, 293-301. Length and width changes in plain-knitted fabric are dependent on the tension applied during knitting and recovery of strains, relaxation of grey fabric, dimensional changes during wet finishing and boarding, and relaxation and/or felting shrinkage. Types of underwear fabric are listed which the finisher is required to bring to the same standard of unshrinkability using machines of different types and gauges. When machines of the most suitable gauge are not available in adequate 4— Chemical and Finishing Processes (Patents) A 6 g numbers, the best results would be obtained by permitting a separate weight specification for the machines of different gauges. The following are discussed: mechanical and other factors influencing the regularity of plain-knitted fabrics; influence of the courses per in. and the diameter of the machine on the width of the grey fabric; dimensional changes of grey fabrics during storage and during soaking; dimensional changes during scouring and boarding of fashioned gar­ ments; influence of knitting structure on the felting shrinkage of untreated and of chlorinated materials. W. Action of Ethylene Sulphide on Wool. T. Barr and J. B. Speakman. /. Soc. D yers

P a t e n t s Wool: Rendering Unfeltable and Unshrinkable. The Greenwood Dyeing Co. Ltd., N. Tullie and W. White. B.P.564,958 of 20/10/1944. The wool is chlorinated or brominated at p H 4 to minimise felting, and then oxidised at :(>i2o° F. to minimise length shrinkage. For chlorinating, hydrochloric acid is added to a sodium hypochlorite solution (14-16 per cent, per weight of wool), and sodium sulphite crystals added to the exhausted liquid to clear the wool, which is then washed. For the second stage of the process,. which need not immediately follow the first, the bath consists of hydrogen peroxide, ammonia and silicate of soda. The qualities of the fibre are unaffected if it is chlorinated in the presence of natural or processing oils. The oxidation appears to modify the sulphur content. The process can be applied to all qualities of wool, yam or fabric and to mixtures containing vegetable or animal fibres. W. Potentiometric Chlorination Control Device. Wallace & Tiernan Products, Inc. (Belleville, New Jersey, U.S.A.). B.P.565,278 of 6/2/1943:3/11/1944 (Conv. 7/2/1942). A method of treating an aqueous liquid with chlorine by a 70 4— Chemical and Finishing Processes (Patents) determining the available chlorine content, or changes in such content, of the liquid and controlling introduction of chlorine therewith comprises detecting the depolarization, or changes of depolarization, produced by the liquid upon a polarized cathode exposed thereto, while maintaining the cathode at a potential within the range of about —0-075 to about —0-2 volt relative to a saturated calomel electrode as standard, the detection of depolarization or changes therein comprising detecting the electrical effects thereof produced across a cell, including the cathode and an anode electrically associated with the liquid, and utilizing the detected depolarization or changes therein to guide or control introduction of chlorine into the liquid. Suitable apparatus is described. C. Cellulosic Textile Materials: Treatment with Formaldehyde. Heberlein & Co. A.G. (Switzerland). B.P.565,337 of 14/9/1942:7/11/1944 (Conv. 20/10/1941). Textile materials composed of natural or regenerated cellulose are treated with solutions of formaldehyde of less than 10 per cent, strength, at temperatures between about 70-160° C., in the presence of catalysts having an acid action, and of stiffening or loading finishing agents which consist of vegetable or animal colloids (e.g. starch or gelatin) or conversion products thereof, and are capable of reacting with formaldehyde to form condensation products which swell sparingly, or are insoluble, in water. After thorough impregnation, the surplus liquid is removed, e.g. by squeezing, and the goods are pre-dried at about 6o° C. Condensation is then effected at about 70-160° C. Impregnated fabrics are stretched in a stenter to predetermined dimensions, pre-dried and then heated to 70-160° C., rinsed, and finished in the usual manner. Fabrics so treated shrink to only a slight extent, even after repeated washing, and have a lasting full handle. Their resistance to abrasion is good and their tendency to swell is greatly diminished. In the case of regenerated cellulose rayon and staple fibre, the tensile strength and resistance to boiling are improved. C. Aminated Chlorohydrocarbon Fungicidal and Insecticidal Compositions. Mathieson Alkali Works. B.P.565,469 of 6/10/1942:13/11/1944 (Conv. 22/10/ 1941). Fungicidal and insecticidal compositions include as the essential constituent products derived by the chlorination and amination of hydro­ carbons, such as the gasoline, kerosene or gas oil fractions of petroleum, the products being used in the form of organic salts, or in solution in hydrocarbon solvents, or emulsified in water. The aminated product is advantageously puri­ fied by boiling in neutral or slightly acid solution, for the separation of acid- insoluble impurities, with subsequent recovery of the purified product by pre­ cipitation with alkali. The purified product may be used as prepared or in the form of salts with fatty acids. The amino product may also be distilled, and either the distillate or the residue, or derivatives of either, may be used as the active agent. In general, the distillates are the more effective insecticides and the residues are the more effective fungicides. The compositions may also include mineral or vegetable oils, wetting agents, etc. C. Diazotype Printed Tracing Cloth: Correction. C. T. Pollard. B.P.565,483 of 8/4/1943:13/11/1944. A process of bleaching the lines of diazotype images carried upon a tracing cloth dressed with starch or other hydrophilic colloid is characterised by the use as a solvent for the bleaching agent of a mixture of water and an organic liquid which does not swell starch or other hydrophilic colloids. The organic liquid may be an alcohfol, ester, glycol, glycol ether or ester, a ketone, dioxan, ethylene chlorhydrin or propylene chlorhydrin. By this method it is possible to reduce or eliminate the production of opacity in the tracing cloth. C. Guanidinium Salt Textile Assistants: Preparation and Application. Courtaulds Ltd. and J. H. MacGregor. B.P.565,675 of 14/1/1943:22/11/1944. Guanidine or aminoguanidine salts of sulphonated aliphatic dicarboxylic acids are produced by the interaction of alkali metal sulphonates of dialkyl esters of aliphatic dicarboxylic acids with guanidine carbonate or aminoguanidine car­ bonate. Suitable esters include the dialkyl esters of sulphonated succinic, glutaric, adipic, pimelic, suberic, azelaic and sebacic acids. The products can be used for imparting a soft resilient handle to textile fibres, and can also act as wetting and dispersing agents, whilst in conjunction with formaldehyde they can be used for imparting wool-like dyeing, properties to cellulose material and 4— Chemical and Finishing Processes (Patents) also to improve the fastness to washing of cellulosic textile material which haą already been dyed with direct cotton dyes. C. Azo Dyes and Intermediate Products: Production. Society of Chemical Industry in Basle. B.P.565,697 of 27/5/1942:23/11/1944 (Conv. 29/5/1941 and 16/4/1942). Dye intermediates are made by esterifying with sulpho-chloro- acetic acid an amine of given general formula, which is capable of coupling with diazo compounds. Suitable amines include N-fmethyl-jS-hydroxyethyl)- phenylamine, N-(/3-methoxyethyl-/3-hydroxyethyl)-phenylamine, and N-(butyl- /3-hydroxyethyl)-phenylamine. The benzene nucleus may be substituted as desired by methyl groups, alkoxy groups, etc., provided that the ^-position to the substituted amino group contains a hydrogen atom capable of exchange by a diazo residue. Monoazo dyes are made either by coupling an intermediate product obtainable as described above with a diazo compound, or by esterify­ ing with sulpho-chloro-acetic acid a dye obtained by coupling a amine of the type specified above with a diazo compound. Diazo compounds of aromatic amines, especially those containing a nitro group in ^-position are suitable. The dyes form salts and the alkali salts in particular, including the ammonium salts are readily soluble in water. They can be used for dyeing cellulose acetate rayon and also, in certain cases for dyeing animal fibres, yellow, red, brown and blue shades. C. Vinyl Resin Coating Compositions. E. I. Du Pont de Nemours & Co. and H. G. Stauffer. B.P.565,707 of 12/2/1943:23/ 11/1944. A vinyl resin coating composition comprises a vinyl halide resin and from 2 to 100 per cent, by weight, based on the vinyl resin content of the composition, of a condensation product obtained from urea, amino triazines or substituted products thereof, aldehydes and monohydric alcohols. The vinyl resin may be a copolymer of vinyl chloride and vinyl acetate. C. Bead Decorated Fabrics: Production. H. Freiberg and S. Freiberg. B.P. 565,711 of 18/5/1943:23/11/1944. A process for decorating the surface of a fabric comprises applying a setting (a device which will encircle a resinous composition, but is open on the side facing the surface and on the opposite side) and applying in the setting a liquid or pasty resinous composition which is allowed to set so that the setting and its resinous inset are firmly secured to the surface of the fabric or the like at least in part by the adhesion of the resinous composition which reaches the surface via the throughway in the setting. The resinous composition may have a basis of synthetic resin, e.g. urea-formalde- hyde resin, and may contain pigments, dyes, fillers and/or hardening agents. It may be applied by means of a piping bag or other apparatus employed in the decorative icing of cakes. The setting may be made of metal, synthetic resin, glass, wood or stiffened fabric. In order to increase the adhesion between the ornament and the fabric a hole or holes may be punched through the fabric in the area to receive the inset so that the resinous composition may pass through the fabric to form a rivet-like attachment. C. Cellulose Ester Materials: Differential Saponification. Courtaulds Ltd., C. M. Whittaker, H. A. Thomas, C. C. Wilcock and C. P. Tattersfield. B.P. 565,73! °f 10/ 3 / 1943:24/ 11/1944. A process for obtaining differential saponi­ fication of fibres, films, woven or knitted materials and the like of a cellulose ester comprises subjecting local areas only of the materials to the action of pressure and thereafter treating the materials with a saponifying agent. The pressure may be applied by means of embossing rollers. By submitting cellu­ lose acetate rayon to pressure by means of an embossing roller suitably engraved, followed by suitable saponifying treatment, e.g. treatment for 10 min. with a 0-9 per cent, solution of caustic soda at room temperature, it is possible to obtain the rayon in a state in which only that part is saponified which has been subjected to pressure. Differential dyeing effects may be pro­ duced by dyeing in a bath containing a dye having a greater affinity for the saponified areas and a dye having a greater affinity for the unsaponified areas. C. Textiles: Waterproofing and Rotproofing. Hardie Trading Pty. Ltd. Australian P. 118,494 (through Text. J. Australia, 1944, 19, 222). T extiles, e.g. canvas, are simultaneously waterproofed and rotproofed by coating or impregnating with an aqueous dispersion of a wax, preferably paraffin wax, using an ammonium soap as the dispersing agent and a cuprammonium solution incorporated in the dispersion, followed by heating to bring about double decom­ A72 5— Analysis, Testing, Grading and Dejects position of the ammonium soap and the cuprammonium solution. The latter may be prepared from copper sulphate and ammonium hydroxide, any copper carbonate present being converted by the addition of a small quantity of sulphuric acid. W. Wool: Reducing Tendency to Felt and Shrink. Holeproof Ltd. Australian P. 118,721 (through Text. J. Australia, 1944, 19, 304). Wool is treated with a solution or suspension of a chlorite which has been activated to develop chlorine dioxide in the solution. Alkali metal or alkali earth metal chlorites are prefer­ ably used, and the solution is activated by heat or by reaction with an acid or with an oxidising or reducing agent. W..

5—ANALYSIS, TESTING, GRADING AND DEFECTS (A)—F i b r e s Cellulose Hydrate Fibres: Structure. A. Marschall and H. Stauch. Kunstseide u. Zellwolle, 1943, 25, 112-117 (through Chem. Zentr., 1943, ii, 284 an d Chem. Abstr., 1944, 38, 4797*)- By use of a technique similar to that of Siebourg a layer showing fibrillar structure and acetylated with difficulty was discovered in the outer portions of fibres which had been spun from the Muller bath. That cellulose of decreased reactivity would thus show a distinctly fibrillar structure could not be predicted from the results of cross-section acetylations. Highly stretched fibres, such as Lilienfeld rayon and stretched and saponified rayon do not show this fibrillar structure. These fibres undergo spontaneous solution at certain defective spots. With fibres produced by the jet progress, acetylation proceeds rather uniformly from the outside layers to the inner portions. The fibres swell considerably and for some time show an outer dividing line, as if they were surrounded by a thin, very elastic outer skin which is difficultly acetylated. C. Fibres: Modulus of Elasticity; Determination by Sonic Method. J. W . Ballou and S. Silverman. Textile Research, 1944, 14, 282-292. Details are given of a method and apparatus for determining the modulus of elasticity of fibres and films by measuring the velocity of sound in them. The method is based on the equation which expresses the velocity of propagation in terms of the elastic modulus and density of the medium. The modulus so calculated is characteristic of a dynamic, essentially adiabatic, high-loading rate, short- period measurement, when a sound frequency of approximately 10,000 cycles per sec. is used. The range of moduli obtained for common textile fibres varied from 1 x io10 to 50 x io10 dynes per sq. cm., the highest values being obtained for linen and the lowest for wool and undrawn nylon. Curves are given show­ ing the effects of stretching on the moduli of rayon and nylon yarns and regenerated cellulose film. C. Polyamide Fibres: Chain Length and Strength. H. Staudinger, H. Schnell and H. Stock. Beih. Z. Ver. deut. Chem. A: Chemie, B: Chem. Tech., 1943, N o. 47, 1-8 (through Chem. Zentr., 1943, ii, 609 and Chem. Abstr., 1944, 38, 48074). The preparation of polyamides from e-aminocaproic acid is described. Viscometric determination of molecular weight in m-cresol gave 3,350 to 26,000 (average of members in the chain, N = 210 to 1,600). Products of N g reater than 300 can be spun into fibres from single jets having a diameter of 0-2 to 0-7 mm. With the lower products further condensation occurs during spin­ ning and no change occurs with products having N = 600. Products of the highest molecular weight become degraded as spinning must be carried out at higher temperatures. This behaviour holds for unprecipitated products as well as those reprecipitated from m-cresol or formamide. The plastic deformation is very large compared with the elastic deformation. In stretched fibres the elastic deformation is greater. Folding strength increases sharply with increas­ ing N. The log of folding strength is almost directly proportional to N, w hilst the tensile strength is practically independent of N. With fibres of equal N the tensile strength of fibres spun from the finer jet is lower. C. Staple Fibres: Longitudinal Swelling and Elongation. W. Weltzien and K. Windeck-Schulze. Beih. Z. Ver. deut. Chem., A: Chemie B: Chem. Tech. 1943, No. 47, 51-58 (through Chem. Zentr., 1943, i, 2655 an d Chem. Abstr., ■ 944, 38, 4807"). A resume is given of earlier work. Measurements of longitudinal swelling and elongation can be carried out in a simple but very 5— Analysis, Testing, Grading and Defects A73 exact manner. Reversible and irreversible swelling phenomena are discussed. Results of swelling and elongation measurements made with different staple fibres are given in tables and curves. It is possible to correlate the variations in longitudinal swelling and in elongation, before and after swelling, even in the case of commercial yarns, with various manufacturing conditions. The results obtained .with rayon are not incidental, but are based on general laws and the longitudinal swelling measurements in combination with the elongation data furnish some idea of the forces which are operative in commercial fibres in the form of inner tensions. C. Staple Fibres: Swelling and Textile Properties. J. Harms and J. Steimmig. Beih. Z. Ver. deut. Chem... A: Chemie B: Chem. Tech. 1943, No. 47, 112-113 (through Chem. Zentr., 1943, i, 2744 and 48082). vFibres rendered approxi­ mately equally resistant to swelling by different finishing methods may exhibit very different relative wet strengths, i.e. the same quantity of absorbed water may lower the strength of the fibre by different amounts. Swelling curves and strength tests show distinctly two types of fibres; it is concluded that in these water is incorporated in different ways. C. Textile Fibres: Properties. Silk J. Rayon World, 1944, 20, March, 48-50, 37; April, 34-38; May, 43-47; 21, June, 42-48; July, 45-48, 51; August, 48-52; Sep­ tember, 35-39. A summary of published information about the structure, dimensions, chemical constitution and molecular structure, and physical pro­ perties, of the chief natural fibres, cellulosic rayons and nylon. C. Textiles: Moisture Relations. P. W. Carlene. /. Soc. D yers cS- Col., 1944, 60, 232-237. A survey of the literature on the absorption and desorption of water by cotton, rayons, wool, silk, jute and nylon, the influence of moisture on the elastic properties, swelling and rigidity of fibres, and the effect of pro­ cessing on the absorbency of textiles. C. Unbleached Pulp Fibre Mixtures: Analysis. A. N oll. Papier-Fabr.-Wochbl. Papierfabr., 1943, 261-265 (through Chem. Abstr., 1944,38,4800’). The method depends on the fact that lignin in groundwood and in soda and sulphite pulps stains differently with certain thiazine dyes in the presence of salts of organic bases. A suitable reagent was prepared by dissolving o • 1 g. pure methylene blue in a mixture of 25 ml. glycol monoacetate and 25 ml. of 4 per cent, aniline sulphate in water. The filtered reagent remained unchanged for months provided light and foreign organic matter were excluded. The mixture of groundwood and unbleached soda and sulphite pulps (carefully freed from size, dyes and fillers) is placed on a microscope slide, dried and treated with one drop of reagent. Groundwood pulp gives a yellow to brown coloration, soda pulp turns deep blue and sulphite pulp remains practically unaffected. Louth’s violet may be used in place of methylene blue. Some of the basic naphthophenoxazines give fairly contrasting staining reactions, but triphenyl- methane dyes and phenoxazines are unsuitable. The method lends itself to quantitative fibre analysis. C. Quartz Fibre Micro-balance. JC. Nanjundayya and N. Ahmad. In d ia n J . Agr{c. Sci., 1943, 13, 649-651. An illustrated description is given of a quartz fibre micro-balance with means for adjusting the tension in the fibre and a glass capillary arm fixed across the fibre by a special aluminium clamp. One end of the arm has a needle point that travels over a graduated quadrant and the other end carries the pan for the object to be weighed. Weights of tufts of cotton fibres are tabulated as obtained on a torsion balance (range 0-5 mg.), a quartz fibre balance of the Denham type (1924; range 0-0-5 mg.) and the new balance (range 0-4 mg.). Agreement is good. C. Coloured Ramie Fibres: Polarized Fluorescence. H. Ziegenspeck. K olloid Z., 1944, 106, 62-64 (through Chem. Abstr., 1944, 38, 48682). A number of yellow to yellow-green fluorochromes of various types were selected for the study of polarized fluorescence. Bleached ramie fibres were soaked in a 1 per cent, aqueous solution of the dye for 12 hours, washed, dried between filter papers, and the fibres stretched taut. Observations were made with oblique lighting, a crossed-filament lamp with filters selected to transmit blue light serv­ ing as the light source. The observations were made with a special dichroiscope of the author’s design. The strongest fluorescence and the most marked dichroism were observed in fluorescein K salt, eosin, coryphosphin, euchrysin and A74 5— Analysis, Testing, Grading and Dejects

primulin. The dyes were adsorbed with their longitudinal axis parallel to the longitudinal axis of the fibres, oriented in the same way as the micelles of the fibres themselves. This is the first time that completely polarized fluorescence has been observed. C. Cotton-Cottonized Hemp or Viscose Rayon Mixture Fabrics: Analysis. A. Cappelli and G. Ferro-Luzzi. Boll, assoc, ital. chim. tessile color, *1942, 18, 101-103 (through Chem. Zentr., 1943, ii, 1250-1251 and Chem. Abstr., 1944, 38, 508Ó9). The method described depends on differences in the time of dis­ solving of cottonized hemp, cottonized viscose rayon and cotton in cupram- monium solution. The proportions are first determined approximately by microscopic methods. C. Cotton: Effect of Paired Reactions on Capillarity. P. P. Viktorov. T ekstil. P rom ., 1944, 4, No. 4, 9-12 (through Chem. Abstr., 1944, 38, 50875). In sub­ stituting caustic soda in the process of bleaching textiles it was observed that the physical changes occurring in the fibre do not become apparent until after another chemical has acted on the fibre. This combined action was noticed with caustic soda and hypochlorite, with mineral acid and soap, and with mineral acid and hypochlorite. This phenomenon is referred to as “ paired reactions of combined action.” To study their effect on the capillarity of cotton fibre, the following " pairs ” were investigated: (1) water and benzene, (2) sulphuric acid and benzene, (3) water and soap, (4) sulphuric acid and soap, (5) water and hypochlorite, (6) sulphuric acid and hypochlorite, (7) Kontakt and hypo­ chlorite, and (8) a mixture of sulphuric acid with Kontakt and hypochlorite. Pairs 1, 2, 5, 6, 7 and 8 were studied in the order of reagents given and in reversed order. The measure of capillarity was the height of ascent of an eosin solution through the warp of the test pieces. Details of procedure are given and the results are tabulated. Pairs 1 and 5 produced no capillarity. Neither of the members of pair 2 caused capillarity, but their combined action, regard­ less of the order, did induce capillarity. In pairs 3 and 4, a o* 1 per cent, soap soliition had no effect, but 0-5 per cent, solutions were effective regardless of the order. Of pair 6, neither the acid nor the hypochlorite was effective alone; combined they caused the eosin to rise regardless of order. Pairs 7 and 8 behaved as 6. Pair 8 gave the best results in regard to evenness of rise of eosin and the uniformity of colouring. The combined action of an acid and bleach­ ing solution is utilized in textile treatments. C. Cotton Fibre: Variability in Uncollapsed Diameter. R. L. N. Iyengar. Indian J. Agric. Sci., 1943, 13, 646-648. A fairly mature cotton boll was plucked, cut open, the locks submerged in water, 80-260 fibres were separated from (a) the micropylar end, (b) the right side, and (c) the /chalazal end of the middle seed of one lock, mounted parallel on a slide in a mixture of glycerol, alcohol and water (1:1:1), and their diameters were measured. The mean values, the standards errors and the coefficients of variability are tabulated for 18 strains of irrigated cotton and 10 strains of rain-grown cotton. Differences between values for the three regions of the seed coat are revealed and the most consistent values appear to be those for the right side. These come between the other values, and have a smaller coefficient of variation. There were fewer immature fibres in this region than at the chalazal end. Measurements on about 200 fibres should give a fairly accurate value of the uncollapsed diameter. C. Long-staple Cottons: Spinning Tests. C otton (M / cr), 1944, 50, N o. 2427, p. 5. Tests were made on the Egyptian types Malaki (Giza 26) and Amon (Giza 39) of a grade approximately fully good/extra, and the Sea Island varieties St. Kitts, Montserrat, and Antigua, which, by Egyptian standards, were graded as “ extra.” The following results were obtained in tests on the cottons in the raw state and when spun into 120s carded yarns:—Fibre weight: 1 -21, 1 -21, 1-40, 1-38, 1-40 m illionths of a gram p er cm .; staple len g th in inches: it t > i £> 'If- !l> iJ; lea product (count x strength): 2,832, 2,948, 2,580, 2,565, 2,410, respectively, for the cottons in the order mentioned above. Length of staple is thus shown to be not the only factor in determining yarn strength as the results indicate that the Sea Island types were longer in staple, but heavier and coarser than the Egyptian ones, and that their strength was much lower. This is believed to be the first test which has shown Egyptian cottons to be stronger than Sea Island cotton, and it confirms the earlier impression that the 5— Analysis, Testing, Grading and Dejects A75 new Amon is a type of unusual importance. Among its numerous valuable characteristics are its high resistance to wilt and its high yield, which is nearly equal to th a t of G iza 7. C. Vinyon Filaments: Thermoplastic Properties. H. E. Shearer. R a y o n T e x ­ tile Monthly, 1944, 25, 431-432. Vinyon for industrial purposes in which thermo­ plastic properties are involved is spun from vinylite (vinyl copolymer) resins in continuous filament and cut staple forms. The older group—Vinyon CF— is made bjr the American Viscose Co. in 190 den.-54 fil. unstretched, 250 den.- 216 fil. stretched, and 200 den.-140 fil. high-stretched forms, which in cross- section are rather like dumbells. This material shrinks and hardens at tem­ peratures above 65° C. and use is made of this property in fabrics to secure crepe effects or to produce semi-rigid moulded and shaped articles. If a plasticizer is used the yarn can be made under heat to coalesce with other yarns. The fine-denier cut staple may be carded readily on a roller card, but an anti-static dressing and a static eliminator are advisable with the coarser fibres. Vinyon CF has been spun alone on woollen, cotton and worsted systems, but is usually blended with other fibres, using up to 20 per cent, of vinyon. Milkweed, kapok, asbestos and “ fiberglass ” have befen " carried ” by Vinyon CF in the form of low-density carded or blown batts or webs. A new type— Vinyon HH2—has a low softening point. A cross-section is shown of a 4-den. cut staple; the shape is almost circular. The material may be used alone to produced hard, board-like sheets or in blends with other fibres to produce felts or blanket-like materials of various densities. C. Wool: Overclassing. “ Ja s o n .” Pastoral Rev., 1944, 54, 597-598. W. Sampling and Measuring Methods for Determining Fineness and Uniformity in Wool. E. M. Pohle, L. N. Hazel and H. R. Keller. U.S. Dept. Agric. Circ. 704, 1944. Wool samples from 6 body regions on each of 10 Rambouillet yearling ewes were examined by the cross-section method to study the efficiency of sampling and of njethods of measuring mean diameter and uniformity of individual fleeces. The variations in fibre diameter associated with sheep, body regions, levels along the fibre, and the various interaction terms were statistically significant. Standard errors calculated from theoretical formulas indicated that samples of completely randomized fibres would be more efficient in number of cross sections prepared and fibres measured per fleece than samples from controlled body regions or from controlled regions and levels along the fibre. Since sampling of completely randomized fibres from individual fleeces appeared to require the opening and mixing of the whole fleece, a less efficient method of blending fibres from definite body regions, suitable for the usual wool laboratory, was investigated. The necessity of preparing a cross section of the fibres from each region sampled was avoided by mixing approximately equal numbers of fibres from the different regions prior to cross sectioning. Several trials indicated that the fibres could be mixed adequately by hand carding small locks of wool from different body regions. Mean diameter and uniformity were estimated (1) by measuring the enlarged diameters of individual fibres, (2) b y counting th e num ber of fibres in an area of 125 sq. cm ., an d (3) b y com ­ paring tfye image of a sample of unknown diameter with those of standards of known diameter. The accuracy of single estimates of fineness by the count and rapid comparator methods was equivalent to that of measuring approximately 75 and 62 fibres, respectively. Both are much faster to apply than measuring an equivalent number of fibres. Average fibre diameter estimated by both methods appeared to be unbiassed, although some evidence was obtained that the deviations of the finest and the coarsest fleeces from the average were under-estimated. Both short-cut methods were sufficiently accurate to dis­ tinguish between uniform and variable fleeces, but were not very accurate in discerning small differences-in uniformity. W. Kemp in New Zealand Romney Sheep and its Significance for Mountain Breeds. F. W. Dry and J. M. Ross. N ature, 1944, 154, 612-613. Kemp suc­ cession relations in plateau array have been studied in 80 covered Romney lambs; the plateau array is the array, lacking sickle-fibres,t of N-type lambs, these being like hairy mountain lambs. With free shedding of hairy-tip-curly- tip fibres (more than 45 per cent?) there is much G„ kemp, and vice versa; with intermediate shedding there is great diversity in G2 kemp. With higher abundance of hairy-tip-curly-tip fibres (męre than 26 per 500 fibres of the A76 5— Analysis, Testing, Grading and Defects

lamb’s full fleece) there is much G2 kemp, and vice versa; intermediate abund­ ance of G2 kemp shows signs of being associated with very poor shedding of hairy-tip-curly-tip fibres, or with low numbers of these fibres. In plateau array abundant G2 kemp is almost always followed by plentiful G3 kemp. In both non-plateau and plateau arrays when G3 kemp is plentiful, G4 kemps' have often at least started tó grow before shearing at about 15 months. The expectation that kemp succession relations in plateau would show a general similarity to those in non-plateau has been justified. There is some evidence that abundance of secondary kemp in N-type is inherited. This work has a bearing on the practicability of judging very young lambs for later kempiness. W.

(B)— Y a r n s Rayon Yarns: Strength, Resistance to Rubbing and Twist. M. Matthes and A. Keworkian. Zellwolle u. Kunstseide, 1943, 1, 1-12 (through Chem. Abstr., 1944, 38, 48084). The theoretical relationship between strength and stretch, and between twist' of rayon yarn and the properties of the individual filaments is discussed. The total load during stretching may be separated into two com­ ponents, of which one causes extension and final breaking of the filaments, and the other acts as a shearing force and increases the friction between the fibres. The second component is obtained mainly by pressure radially to the yarn axis and increases with each layer of fibres to the centre of the yam. On account of this pressure all the filaments fail in practically the same place, giving a clean break. Increase in degree of twist increases the strength, but not as much as with spun fibres in which friction relations are different owing to the much shorter fibre length. Beyond the critical degree of twist, yam strength is decreased for both rayon and spun fibres owing to the ultimate stretch of the individual fibres. Bending and torsion stretch cause a decrease in strength. Resistance to rubbing was determined with an apparatus in which yarns are rubbed at right angles to each other under a load of i/5th-i/2oth of fjie tear strength. The test values (S) agree with Gauss’s distribution law accord­ ing to the formula S = N £t X in w hich N m= yarn number and X = number of double robbing motions. The experimental results agree with the theoretical deriva­ tion. Rubbing resistance of rayon yarn is highest for parallel arrangement of individual filaments and decreases with increase in degree of twist. Cupram- monium rayon showed the highest strength but lowest stretch, acetate rayon had the lowest strength and highest stretch, whilst viscose was intermediate. With increasing fineness of filament, the tear strength of rayon fibre increases whilst the rubbing resistance decreases. The rubbing test is more sensitive to non-uniformity or damage of yarn than tear strength and is therefore preferred for routine testing. C. “ Grex ” and “ Poumar ” Yarn Count Systems. (1) S. L. G erh ard . (2) A. G. Scroggie. Rayon Textile Monthly, 1944, 25, 375-376, 429-430. (1) The author welcomes the decimal feature of the “ Grex ” system, but not the metric units of length and weight. He suggests as a unit the number of “ POUnds per Million yARds ” ( = “ Poumar ” ) and gives a table of equivalent counts on this, the Grex, and the established systems. Thus, 23-8 and 119 on the cotton system are 50 and 10 poumars, respectively. The equivalents in Grex units are 248 and 49-6. (2) The case for the metric units of length and weight is argued. C. The Spinning Test Method, “ Questor.” W ool R ec., 1944, 66, 745-750. The spinning test method, which consists in counting and recording the number of end breakages that occur on the frame in a given time while the test material is being spun, gives results capable of direct interpretation in terms of spin­ ning quality. It may be used to study the effect on the spun yam of (a) alterations to machine details, e.g. different types of cap, (b) alterations affect­ ing the material, e.g. different methods of roving preparation, and (c) altera­ tions to environment, principally in the degree of relative humidity or tem­ perature. The safest conditions are found when tests are restricted to a single side of one frame only. Details are given of the recording of the data and of the time factor. > W. Yarn Strength as an Index of Quality. “ Questor.” W ool R ec., 1944, 66, 873-874. The hank strength test alone is inadequate for small-scale tests which are often carried out prior to bulk testing. It should be supplemented with single thread tests if yarn structure is concerned; the results of hank and 5— Analysis, Testing, Grading and Defects A77 ballistic tests should be compared if it is a question of the material of which the yarn is composed. For single thread testing, the Moscrop machine is pre­ ferred to those which take only one thread at a time; it has the advantage in convenience and speed, and also provides information about strength variability along the yarn. W. Mill Testing: Machinery Modifications. "Questor.” W ool R ec., 1944, 66, 789-792. Mill testing is discussed as concerned with the effects of machinery modifications on some quality of the product, e.g. the installation of a new type of condenser in woollen carding. It is essential that only a single alteration at a time should be made to the machine. Testing should be done over as long a period as possible both before and after the alteration, careful records being taken of the machine’s performance. A testing routine is a considerable help when such alterations are made, as the results provide the data required. In keeping such routine records, a distinction must nearly always be made between records of definite quality, e.g. strength, count variation or irregularity of the finished yarn or sliver, and records of quantity (production). In considering the results of a change, the effect on production should always be judged against any corresponding falling-off in quality, and the records should con­ tinue for some time in case the change made has a delayed effect, e.g. increased spindle speed leading to rapid wear and vibration and a falling-off in yarn quality. . W. Mill Testing. " Questor.” W ool R ec., 1944, 66, 702-705. The mill tester should only undertake investigations which require well-established and accepted techniques; he should not be involved in work in which the factors involved and the outcome are obscure; the latter type of work is more in the field of the research worker. The scope of the mill tester’s work, which is wide and embraces both the quality and quantity of the product, is discussed, including consideration of test data collected over the course of time, selection of equipment, sampling procedure, and co-operation with operatives and with the research, laboratory. W.

(C)—F a b r ic s Damaged Linen Goods: Examination. Textile Mercury & Argus, 1944, 111, 468-475, 588-590, 666-8, 675. A useful review is given of fluidity, solubility number, loss on boiling with alkali and copper number tests for assessing the extent of damage in linen goods, illustrated by examples. C. Gas Penetration Measuring Apparatus. F. R. Smith and M. Kleiber. In d . Eng. Chem., Anal. Edn., 1944, 16, 586-587. The construction and operation of an apparatus for measuring the rate of gas penetration through food- packaging materials are explained with the aid of a diagram. The apparatus has been designed chiefly for measuring the rate of penetration of oxygen from the air and for this purpose nitrogen is passed into a diffusion chamber which is closed at one end by a piece of the material being tested and samples of the gas are withdrawn at intervals and their oxygen contents determined. C. Reinforced Synthetic Resins: Microscopic Examination. Clementina M. Gordon. /. Soc. Chem. Ind., 1944, 63, 272-277. A technique is described for preparing microscopic sections of plastics and for differentially staining the various kinds of resins and fibres intended for use as structural materials. The application of this technique to the study of resin-impregnated paper, cotton fabric and acetylated cotton fabric, and boards prepared from them is described. The staining reactions and observations of changes in refractive index and dichroism of the fibres indicate that phenolic resins can penetrate the cellulose fibre wall and, on condensing there, form a combination, possibly of the lignin- cellulose type, which alters the staining and optical properties of the fibres. This does not occur at pre-cure, but subsequently in the press, owing to the temperature and not to the pressure. The effect varies with the type of fibre and to a small extent with the type of resin. The strength of the resin-fibre bond increases with the modification of the fibre, and influences the way in which the board fails and its property of pseudo-ductility. No clear correlation exists between the mechanical properties of a board and its microscopic appearance. C. Spun Rayon Fabrics: Quality. — Werzmirzowsky. Beih. Z. Ver. deut. Chem., A: Chemie, B: Chem. Tech., 1943, No. 47, 59 (through Chem. Zentr., 1943, i, A78 5— Analysis, Testing, Grading and Defects

2655 an d Chem. Abstr., 1944, 38, 48083). There is no direct relation between actual wear tests and the results of technological measurements. The highly polymeric fibres of the Lanusa type show great tension and thus a smaller tendency to “ splintering” and better general behaviour in actual use, par­ ticularly when used in the form of knitted fabrics. C. Cloth: Thickness Measurement. J. Textile Inst., 1944, 35, S1-7. C. Narrow Fabrics: Testing. / . Textile Inst., 1944, 35, S4-40. C. Table Napkin Fabrics: Serviceability. Lottie E. Sumner and Elizabeth D. Roseberry. Rayon Textile Monthly, 1944, 25, 377-380. Table napkins of three different types (a) all linen, (b) cotton, permanently finished, (c) rayon weft/cotton warp, each type at three different price levels, were kept in service 3 days a week for 32* weeks and laundered, weekly and their behaviour was checked by routine tests. The observations are recorded in the following tables: (1) price, weave, dimensions, weights, ends and picks per inch, yarn counts and twists; (2) breaking loads, wet and dry, before and after 32 weeks’ wear; (3) loss or gain in weight per square yard; and (4) shrinkage, warp- and w»ft-way, after 1, 2, 3, 4, 5 and 32 launderings. The laundry and testing methods are briefly but adequately described. Judged by loss of strength and weight, the linen napkins were the least satisfactory. The permanent finish of the cotton napkins was effective in preventing loss of lint and giving a firm handle right to the end of the test, but not in reducing the shrinkage. The rayon yarns resisted deterioration better than the cotton or linen yarns. C. Towels: Quality. N. G. Bennett and P. E. Keeney. Missouri Sta. Bid. 452, 1942, 32 pp. (through Exp. Sta. Rec., 1943, 88, 573). As guides for judging the quality of towels and towelling materials, obtained in various qualities and prices at representative stores in Missouri, laboratory tests were made of weight, tensile strength, thread count, colour fastness and water, absorption capacity. 'The findings were compared with the guidance afforded the consumer by the usual methods of inspection, reliance upon trade-marks and brand names, past experience, and price. With terry towels, in which strength and hence durability depended upon the number of yarns to the inch in the background of the towel and absorbability upon the weight, which involved length and close­ ness of pile, the usual buying guides were inadequate or inefficient. Price was no indication of quality. Inspection served mainly to distinguish between the highest and the lowest grade, it being very difficult to distinguish between similar grades. The majority of terry towels tested were fast to both sunlight and laundering. For tea towels and towelling materials, made of cotton, linen, or mixtures of these or rayon mixtures, thread count was no reliable indication of durability, because of the variation in the size of the yarns. Towels and towelling of each fibre content varied considerably in strength. Tensile strength depended upon a combination of the fibre content of the yarns, the number of yarns to the inch, and the size and amount of twist in the yarns. Price was no indication of durability or strength. About one quarter of the materials tested were not fast to light, but most of them were fast to laundering. Towels of cotton absorbed the greatest amount of water, but those of linen absorbed moisture more rapidly and dried much faster than the others. Flour sacking, which ranked above the average in all tests except those for tensile strength and colour fastness, proved to be a very satisfactory type of towel for the m oney expended. C. Wearing Tests on Fabric Blends of New and Reclaimed Wool Fibre. H . M. Ward and B. Bailey. J. Agric. Res., 1943, 67, 485-500. The fabric tested was navy flannel, woven from yarns composed of new wool from Rambouillet sheep and high-quality sweater clippings blended in various proportions. The clip­ pings are designated “ reclaimed wool,” to avoid the use of the term “ repro­ cessed ” as defined by the Wool Products Labelling Act. After dyeing by a commercial dyer, the fabric was made into skirts which were issued to women students at the South Dakota State College for a period including 1,000 hours of wear and 7 dry-cleanings. Physical and chemical tests were made after dyeing, after wearing and after storage. Breaking strength, both warp- and weft-wise, and bursting strength decreased with increase of reclaimed fibre. Nitrogen and sulphur contents decreased with increase of reclaimed fibre, chemical deterioration being more pronounced after wearing than after storage. The findings do not support the statement in the Wool Products Labelling Act 8— Building and Engineering A79

that wool fibres reclaimed from unused knit material are not damaged sufficiently “ to seriously diminish their original, natural intrinsic protective and service qualities.” W. Wool: Warmth. W. R. Lang. Pastoral Rev., 1944, 54, 520-521. A short review of published literature on the factors involved in wool’s property of w arm th. W . 8—BUILDING AND ENGINEERING

(A)— C onstruction a n d M a in t e n a n c e o f B u il d i n g s a n d P l a n T Composite Plastic Materials: Properties. H. C. Engel and W. W. Troxell. Modern Plastics, 1944, 22, No. r, 133-139, 170-172. Requirements of sandwich materials, composed of stiff dense faces separated by a thick light core, for use in aircraft construction are 'discussed. Phenol-formaldehyde and urea- formaldehyde resins, polystyrene, polyvinyl chloride, polyvinyl formal, cellu­ lose acetate and several of the so-called “ allyl ” thermo-setting resins have been expanded into porous structures for use as core materials, and a pulp base core material comprising approximately equal proportions of resin and wood pulp has also been used. Curves are given showing the variation in the properties of such core materials with variation in specific gravity. Flexural characteristics of sandwich-type boards are discussed and curves are given showing stiffness against per cent, core by weight for boards having metal, wood, paper and fabric surfaces and fibre-resin cores. Various physical pro­ perties of the sandwich materials are tabulated. The need for waterproofing such materials is pointed out and the results of measurements of moisture absorption of specimens before and after the application of protective coatings are discussed. C. Insecticides: Application. R. C. Roark. Chem. and Eng. News, 1944, 22, 1464-1469. A broad discussion of the supply and consumption of insecticides and fungicides in the United States, substitutes for copper and arsenic com­ pounds, rotenone and pyrethrum, the possibilities and uses of fluorine com­ pounds, nicotine compounds, organic fumigants, synthetic contact insecticides, D.D.T. [2 : 2-bis(^-chlorophenyl) 1 : i : 1-trichloroethane], and Eulans and other mothproofing agents, the use of synthetic organic compounds as substitutes for lead arsenate, the synergism of insecticides, organic fungicides, and new methods of applying insecticides. C. Machine Bearings: Selection and Maintenance. H. Miedendorp. R a yo n Textile Monthly, 1944, 25, 399-401. A general discussion of the value ot “ anti-ftiction ” (i.e. ball or roller) bearings. Published information on the power consumed in friction by ball, roller or Babbitt metal bearings is sum­ marised, the relationship between the number and diameter of balls and the load capacity is discussed, and hints are given on the mounting, lubrication and protection of anti-friction bearings. C. Plastic Bearings: Properties and Uses. E. H. G. Sargent. Industrial Chemist, 1944, 20, 577-584. Plastic bearings are made from reinforced phenolic resin plastics, chiefly those containing cotton. The resistance of such plastics to water and chemical reagents is discussed and a table of properties is given. Industrial applications of plastic bearings are considered, and different types of these bearings and their installation and lubrication are described. Wearing properties and common causes of damage are briefly discussed. C.

(C)— S t e a m R a is in g a n d P o w e r S u p p l y “ Metadyne” Direct Current Generator. Metropolitan-Vickers Electrical Co. L td . Silk <&■ R a yo n , 1944, 18, 1228-9. The metadyne is a form of d.c. generator designed to provide a large amplification (up to 10,000 to 1) of the input power that can secure accurate control or variation of speed, torque, current, voltage or position of a load whether in motion or at rest. It is particularly quick in response and can be used effectively with electronic or photo-electric control circuits. Wiring diagrams are provided to assist a technical description of the device. • C. Boilers: Cracking and Embrittlement. H. N. Boetcher. Mechanical Engineer­ ing, 1944, 66, 593-601. A discussion of the characteristics and causes of the principal types of cracks, crack-like penetrations and embrittlement found in a 8 o 8— Building and Engineering pressure parts of boilers, with particular consideration of caustic cracking and of high-pressure-tube embrittlement. Photo-micrographs are given. C. Creosote-Pitch Firing on Economic Boilers. Steam Engineer, 1944, 14, 44-7. Five economic boilers, supplying steam to a laundry and a dairy, have been converted to creosote-pitch firing as the supply Of oil has become limited. Special plant has been installed to maintain the fuel at a temperature of ii0°-i20° F., so that it can easily be handled by the feed pumps. Photographs and drawings make the installation clear. La. Instruments for Lancashire Boilers. Steam Engineer, 1944, 14, 57-9. In answer to a query, the best way of using a number of boilerhouse instruments on a battery of six Lancashire boilers is considered. A typical log sheet is illustrated and described briefly. La.

(G)— H e a t in g , V e n t il a t io n a n d H umidification Dull-emitter Elements: Application in Infra-red Heating. E. C. Maling. Electrical Review, 1944, 135, 370-372. It is pointed out that equal amounts of heat radiated for a given time from the same source will not cause the same temperature rise in materials of different kinds and that a selection should be made of the wavelength band most suited to the material to be treated if efficient heating or satisfactory drying is to be accomplished in the minimum of time. For the dehydration of pottery clays, for example, it is best to choose long-wave radiation that will penetrate the mass and drive the moisture out­ ward, otherwise rapid drying at a high temperature may cause internal steam pressure to crack the surface. For similar reasons it is desirable to pre-heat complicated fabrications which are built up of several materials of different thermal conductivities. For this purpose direct infra-red radiation from dull- emitting sources is very suitable, enabling the initial drying to be effected with longer-wave emanations which can be shortened during the final baking period at higher temperature. Dull-emitter elements are also suitable for the pre-heating of plastics and of resin-impregnated materials for the construction of laminated sheets. Some advantages of the dull-emitter elements are pointed out and the design of suitable reflectors is discussed. Chromium is very suitable for commercial usage .with dull-emitter sources in the near infra-red band approximating to 3^ wavelength. Copper and silver, when suitably lacquered, and gold, rhodium and anodised aluminium are all good reflectors when protected against oxidation. C. Cardroom: Air Conditioning. F. Wright. Textile Weekly, 1944, 34, 994, 996, 998. The writer answers the objection against using re-circulate4 air in the cardroom by working out the cost for steam if fresh air only is used. In a typical case, he argues that by re-circulating 65 per cent, of the air and cleaning it by passage through a " fly ” interceptor, a dust filter and an air- washer, no steam would be required for heating the air. C.

Infra-red Lamps: Industrial Applications. F. E. Rowland. D iscovery, 1944, 5, 277-280. A discussion of infra-red lamps as sources of radiant heat, tem­ peratures attained in articles subjected to radiant heating, the design and advantages of infra-red lamp heating plants, and applications for drying paints, coil varnishes and foundry moulds, acelerating the setting of adhesives, heating and curing purposes in the textile industry, softening plastics, and other purposes. C. Radio-frequency Heating Equipment: Application. E. T. Norris. Electrical R eview , 1944, 135, 472-474. The author weighs up the advantages and dis­ advantages (prime and running costs) of radio-frequency heating and concludes that the following characteristics appear worthy of consideration: (1) For dielectric heating, the generation of heat homogeneously within the material, resulting in uniform distribution of temperature in materials of poor thermal conductivity; (2) for induction heating, the generation of heat superficially in the material, resulting in uniform distribution of temperature over the surface, a useful achievement in the surface treatment of metals and in the curing of plastics; and for either type of heating, (3) the accurate localisation of heating for a particular treatment; (4) a higher rate of heating, and therefore increased production; and (5) ease and accuracy of control of the degree of heating. C. 8— Building and Engineering (Patents)

Thermostatic Control Devices. T. Thorne Baker. Electric Review, 1944, 135, 811-813. Brief descriptions are given of a toluene expansion thermostat, the Hearson capsule, a controlling relay circuit, the Cambridge precision regulator, the “ Microid ” temperostat, and devices for controlling oven and room tem­ peratures, with special reference, to their electrical characteristics. C. Dusts: Explosion Risks. D. F. Twiss and W. McCowan. India-Rubber J., 1944, 107, 292-293. Risks of dust explosions in rubber factories are discussed and a convenient method for testing the explosive possibilities of powders is described. • C. Flue Dust: Electrical Precipitation. (1) John Bruce. (2) M em bers of th e Institution of Electrical Engineers. Electrical Review, 1944, 135, 626, 675-676. (1) Brief reference is made to experience at the Swansea power station to the effect that electrical precipitators (for flue dust from anthracite duff) need to be provided with means for controlling the mass flow of the gas so that each parallel electrode field shall be furnished with an equal volume of gas under all load conditions and also to ensure that the velocity is uniform throughout the cross-section of each field. The author believes that unequal gas velocities and non-uniform distribution of dust within the gas (apart from “ bird-nesting ” and back-ionisation) will often explain erratic behaviour in commercial pre­ cipitating plant. (2) A general discussion is reported of the paper briefly referred to above. The points raised include particle size, effective gas tem­ perature, and production of ozone and oxides of nitrogen. C. (H)— W a t e r P urification Porous Metal Filtering and Diffusing Units: Properties. J. W. Lennox. Industrial Chemist, 1944, 20, 600-604, 615. Metallic filtering and diffusing units are made by the pressing and sintering of metal powders carefully graduated in order to develop pre-determined pore sizes. The total porosity by volume is adjusted by control of pressure and temperature during sintering. These materials are at present manufactured in the form of sheets, discs, and conical capsules. The alloy at present employed is a 90/10 bronze, but develop­ ment work is being undertaken with copper-nickel alloys. Machining operations should be avoided and the material preferably moulded to the required shape. The total porosity by volume can be varied over the range approximately 1 0 -6 0 per cent, and the size of pores from 1 to 5 0 /i. Apparatus for measuring permeability to liquids and permeability to air, and an arrangement for demon­ strating the use of the porous material for the separation of mixed liquids of different surface tension are shown diagrammatically and results obtained with materials of different grades and thicknesses are discussed. Results of bending, shock resistance, tensile and hardness tests are briefly discussed. The advantages of these potous metal filtering and diffusing units are pointed out and various applications are mentioned. C.

P a t e n t s Air Filter. Sigmund Pumps (Great Britain) Ltd. and A. Laszlo. B.P.565,265 of 9/7/1943: 2/11 11944. A filter for freeing air from noxious gases or dust is made up of a number of rings of filter paper or like filtering material arranged concentrically one within another and standing on edge. The rings may be cylindrical, or they may be conical. In the case of the rings being successive sections cut from a cone, each ring will have an edge of substantially the same diameter as one edge of the succeeding ring or section of the cone. If these rings are placed concentrically one within another, each alternate successive ring being inverted, adjoining rings will make close contact with one another along the edges and form a circular body having a radial section of zig-zag form. The edges of adjoining rings are on both sides of the filter sealed together by a sealing medium in grooves in relatively stiff bodies having perforations between the grooves. C. Spongy Cellulose Derivative Materials: Production. J. G. Williams. B.P. 565.343 of 14/12/ 1942 : 7/ 11 /1944. Cellular material is made by forming from an ester or ether of cellulose a gel containing a true solvent for the ester or ether, replacing the solvent by an organic liquid which is a non-solvent for the ester or ether and is miscible with the solvent, and then effecting the evapora­ tion of the non-solvent at a temperature sufficiently low to avoid collapse of the gel structure. The gel may be made by the addition of non-solvent to a A82 9— Pure Science solution of the cellulose derivative in a mixture containing a n®n-solvent and a solvent for the cellulose derivative. In an example, a gel having a basis of cellulose acetate and in which the liquid constituent is a mixture of acetone, benzene and ethanol, is soaked in benzene to replace acetone and ethanol, and the benzene is then evaporated. The products obtained have low specific gravity combined with toughness and rigidity and resistance to crushing. They may be used as heat and sound insulating materials and, on account of their buoy­ ancy, in the construction of floats, pontoons, etc. They may be impregnated with liquids and used as sealing rings, washers, etc. Surface pores may be sealed by the application of suitable coating compositions. C. Air Cleaner Filter Unit. A. M. Goodloe (Montclair, New Jersey, U.S.A.). B.P.565,740 of 20/5/1943:24/1/1944. A removable filter unit for oil bath air cleaners comprises an interstitial filter body mass enclosed in a tubular knit wire mesh sleeve, the interlinked bights of its knit loops being disposed to lie along and project from the inner surface so as to interlock with the contiguous surface of the filter body, whilst the legs of the knit loops lie along the outer surface of the sleeve in a substantially continuous common plane, whereby to provide the sleeve with a relatively smooth exterior face. The filter body mass is provided with end plate elements having perforated bottom portions and peripheral collar flanges, to engage over the end portions of the assembled filter body mass and the side wall means. The mass preferably comprises super­ posed corrugate plies of knitted metallic mesh so arranged that corrugations of contiguous plies cross one another, the exposed corrugations at the external surface of the filter body mass providing projections adapted to roughen the surface and interlock with the wire mesh sleeve. C. Water: Treatment for Colour Removal. F. Aldred and Imperial Chemical Industries Ltd. B.P.565,824 of 24/5/1943:29/11/1944. A process for the removal of colour from natural surface waters comprises treatment with one or more aluminates of magnesium or calcium while maintaining a pH between 4 and 8, preferably for 5.-30 min., and separating the insoluble material from th e w ater. C. Fabric-covered Filter. American Viscose Corporation. B.P.565,840 of 13/4/1943: 30/11/1944 (Conv. 15/8/1942). A filter structure is composed of a filtering body about which a covering fabric of stretched thermoplastic material is shrunk in place. The shrinkage is preferably effected by heating a seamless tube of the fabric into which a filter body is inserted. The shrinkage is accom­ panied by a certain amount of fusion which produces a stiff, smooth surface. The filtering body may be of any conventional character, such as of a wound fibrous material, a wound gimp material, or any porous body such as chamois, stone or ceramic ware. , C. 9—PURE SCIENCE Moulds: Methods of Study. A. Fleming and G. Smith. Trans. Brit, mycol. Soc., 1944, 27, No. 1-2, 13-19 (through Rev. Appl. Mycol., 1944, 23, 351-352). Excellent preparations of mould colonies can be obtained and preserved by sterilizing disks of paper or Cellophane in an autoclave, placing them on the culture medium in a Petri dish, and then inoculating them in the centre. When the resultant colony has reached the desired size, the disk can be removed, exposed to formalin vapour, dried and then mounted on a card or glass and protected with a glass covering. A flat spectacle lens blank covered with a curved spectacle lens blank, may also be used in mounting. With Cellophane disks and some moulds, the colony floats off when the disk is placed on water or 10 per cent, formalin and can be transferred to a glass mount. In observations of spore germination, small Cellophane squares or disks were placed on a solid medium and mould spores planted on the surface of the Cello­ phane. After sufficient time for growth, a Cellophane slip was removed and mounted in 10 per cent, nigrosin (containing formalin). For immediate examination the Cellophane serves as a cover-slip, and the germinated spores stand out clearly on a dark field. For permanent record a slip with nigrosin added and dried may be mounted in Canada balsam. For positive staining of recently-germinated spores the best results are obtained with lactophenol- picro-nigrosin, the preparation being sealed with Noyer’s cement or any other suitable material. For mounting moulds the most satisfactory medium for 9— Pure Science A83

general use is lactophenol. Directions are given for sealing lactophenol mounts. C. Gelatins: Bacteriological Test. A. Steigmann. /. Soc. Chem. Ind., 1944, 288. Details are given of a test based on the fact that the liquefying or facultative aerobic bacteria, which can cause much trouble in gelatin factories produce catalase or an enzyme with similar action. The catalase decomposes hydrogen peroxide and the liberated oxygen is measured by gas-volumetric methods or (more rapidly) in the form of oxygen bubbles produced and fixed in gelatin gels. The test may be applied to gelatin solu­ tions and to water squeezed out from the filter cake or waste water from raw materials or installations. In gelatins dried at p H 5-7 or lower, part or all of the catalase is destroyed. Dried gelatins do not therefore reflect the state of bacterial infection prior to drying. C. Silica in Steam: Photometric Determination. 1^. G. Straub and H. A. Grabowski. Ind. Eng. Chem., Anal. Edn., 1944, 16, 574-575. Methods of determining silica in condensed steam in the presence of phosphates, depending ,on (1) measurement of the blue colour developed by reducing the yellow silicomolybdate complex with sodium sulphite at a suitable p H , a n d (2) measurement of the yellow colour of the silicomolybdate complex after adding oxalic acid to destroy the phosphomolybdic acid complex, are discussed and a sensitive method is suggested which depends on formation of the silicomolyb­ date complex, addition of oxalic acid, reduction of the solution with i-amino- 2-naphthol-4-sulphonic acid in sodium sulphite-bisulphite solution, ćtnd measurement of the transmittance at a wave length of 700 m/t. This method has an accuracy of 0 01 p.p.m. in determining silica in amounts from 0-02 to 2-o p.p.m. when a 50-ml. sample is used. C. Synthetic Resins and Plastics: Identification. T. P. G. Shaw. In d . E ng. Chem., Anal. Edn., 1944, 16, 541-549. Details are given of a systematic pro­ cedure for the identification of synthetic resins and plastics. The general order followed on an unknown sample is: (1) Separation of the resin or resins from solvents, plasticizers, fillers, pigments, and dyes; (2) Separation of mixtures into individual resins; (3) Classification of the separated resin according to group tests; (4) Identification by following the scheme for the group into which the resin falls; (5) Confirmation by specific tests. A classification of resins according to types and general reactions is given which is useful for the deter­ mination of the type of resin in cases where the confirmatory tests do not yield a clear-cut identification or where distinction between only a few substances is required. C. Water: Dissociation. R. J. Dwyer and O. Oldenberg. /. Chem. Phys., 1944, 12, 351-361. The energy of dissociation of water into H + OH was measured by an experiment developed from the method of Bonhoeffer and Reichardt. A spectrograph of high resolving power served for the measurement of the intensity of the absorption spectrum of OH in a heated mixture of water vapour and oxygen. The result (for o° K) was H + OH—kH 20 - 118 • 2 + o- 7 kcal. and O + H—>OH— 100 ■ 1 + 0 9 kcal. The probabilities of transition of the lines of the OH band were recomputed. C. Gelatin: Preparation. W. M. Ames. J. Soc. Chem. Ind., 1944, 63, 277-280. Gelatin prepared by the alkaline method contains 0-5 per cent,, less nitrogen than gelatin extracted with acid. The iso-electric point of untreated collagen lies between p H 6 and 8, and that of limed collagen between p H 4-9 an d 4 -6. The ammonia evolved during extraction of limed material is negligible, so that the loss of nitrogen takes place during the soaking period. By determining the acidity and pH values of a sample of gelatin and comparing with acidity /J?H curves for acid-, alkali- and water-extracted gelatin it is possible to determine the method by which the sample was prepared. C. Moulded Cellulose Esters: Solvent Immunization by Surface Hydrolysis. W. M. Gearhart. Modern Plastics, 1944, 22, No. 1, 140-141, 172-174. Limited protection against various solvents is imparted to moulded cellulose ester plastics by dipping in a solution containing 1-5 per cent, of an active hydro­ lysing agent, such as sodium or potassium hydroxide or sodium methylate, and 25-100 per cent, of a softening agent, such as methanol, ethanol, dioxane or acetone. Tables are given showing the effect of 1-minute and of continuous immersion of untreated and treated cellulose acetate and acetate butyrate 9— Pure Science

plastics in various solvents. None of the 18 solvents tested appreciably harmed the surface of the treated plastics in a i-min. immersion. The results of 16- and 36-hour immersion tests show that surface hydrolysis gives good protection against long-time exposure of both cellulose ester plastics in solvent types of plasticizers such as triacetin or dimethyl phthalate, but is not effective for continued exposure to very active solvents such as acetone or the Cello- solves. The treated esters are swelled and softened by ethanol and methanol. Surface hydrolysis gives good protection to both cellulose esters against oil of pennyroyal, oil of lavender, and oil of wintergreen. Both treated and untreated esters are unaffected by oil of eucalyptus, oil of citronella and oil of lemon. C.

Dilute Soap Solutions: Conductivity and Concentration. P. Ekwall. K olloid Z., 1 9 4 2 , 101, 1 3 5 -1 4 9 (through Chem. Zentr., 1 9 4 3 , i, 7 1 2 -7 1 3 and C hem. A b str., 1 9 4 4 , 38, 4 4 93 2). Trhe relation of equivalent conductivity and equivalent concentration were determined for aqueous 0 -0 0 2 - 1 -o n . solutions of sodium caprate, laurate, myristate, palmitate and oleate, at temperatures of 20°, 17-70°, 17-80°, 17-67° and 1 7 ° , respectively. The positions of critical concentrations were determined as 0 - 0 9 5 - 0 - i n . , o -2 8 n ., 0-0711., respectively, for the first three salts at all temperatures, and 0 -0 0 3 2 1 * . for the palmitate from 5 2 ° upwards. For the oleate, no critical concentration appears from the equivalent conductivity / concentration curve, the deviating character of which is probably connected with unsaturation. At the critical concentration the curves of the salts of saturated acids fall sharply. Below this concentration the course of the curves deviates increasingly from the curves for electrolytes as the mole­ cular weight of the acid increases. At extreme dilution the curve again breaks sharply. The effects on conductivity of hydrolysis, carbon dioxide, and excess fatty acid are discussed and equations are set up for correcting them. Mobilities a t 2 0 ° .were determined as 20-8, 19-9 a n d 1 8 -2 for caprate, laurate and myristate ions, respectively. C.

Water Absorption Determination Apparatus. F. H. Muller. Kolloid Z ., 1943, 105, 16-20 (through Chem. Abstr., 1944, 38, 44912). The sample is placed in an apparatus that can be evacuated to low pressures. The sample is first connected to a flask containing pure water. After equilibrium has been established, the moist sample is connected to a vessel immersed in a liquid-air bath. Afterwards the water from the sample condensed in the cold bath is removed and the vessel allowed to warm to room temperature. The pressure is read on a mercury manometer, and from the known volume of the vessel the weight of water is determined by the gas law. The method is rapid (total time for a determination may be several minutes to one hour) and can be used on samples of the order of 1 mg. Even for very small water uptake the accuracy is estimated to be 10-15 Per cent. Typical results for the water uptake are polystyrene 0-15-0-20 per cent., Vinifol 0-3-0-4 per cent., cellulose triacetate 6-10 per cent. The method is not applicable to substances in which hysteresis effects occur in the sorption and desorption of water or in which the equilibrium is established very slowly (rubber mixtures). C.

Particles: Measurement. P. G. W. Hawksley. British Coal Utilisation Res. Assoc. Monthly Bull., 1944, 8, 245-257. A review of recent work on methods of measuring particle size, particularly in the sub-sieve range from 200 B.S. mesh (76/*) down to the finest measurable sizes. ' C.

Potato-starch Particles; Cation Exchange on —■ J. Dykyj and J. Bena. Ktlloid Z., 1943, 104, 106-112 (through Chem. Abstr., 1944, 38, 4494-’). P o tato starch containing Ca was suspended in solutions containing o • 1 equivalent of ferric chloride, calcium chloride, or their mixtures and the exchange of ions was determined from analysis of the ash. Agreement was found for ion exchange on starch between experimental values and values calculated by the law of mass action in which activity coefficients were used. Starch with NH4+ readily exchanged this ion for others, but Ca, Ba, or Fein ions were replaced by NH,+ with some difficulty. Ease of exchange depended also on freshness of preparation. Ca and Ba were removed completely with dilute acid only. When Fln starch was dried, exchange properties were lost, but it then took up more Fin and behaved like colloidal particles of hydrated ferric oxide sols. C. 9— Pure Science A85

Cellulose: Alkali Solubility and Degree of Polymerisation. A. Mars chalk Zellwolle u. Kunstseide, 1943, I, 117-122 (through Chem. Abstr., 1944, 38, 50797). There is a direct relationship between the degree of polymerisation (D.P.) of cellulose and its solubility in 10 per cent, caustic soda solution only with uniform preparations of the same'source material. Different samples undergoing the same treatment, such as regeneration and oxidative or hydro­ lytic degradation, or the same -material undergoing different treatments, even at the identical ultimate D.P., show a different alkali solubility. C. Leoti Sorgo: Culitivation for Starch. R. L. Cushing. Nebraska Sta. Cir. 69, 1942, 41 pp. (through Exp. Sta. Rec., 1943, 88, 475). Leoti sorgo, a popular sorghum giving satisfactory yields "in most parts of Nebraska and also suitable for syrup, has a waxy endosperm that yields starch with properties similar to those of tapioca starch. Experimental data indicate that on the average, in areas where sorghums are best adapted, particularly in the central and south- central areas of Nebraska, Leoti should compare favourably with corn in grain yield. Cultural practices and harvesting methods are set forth briefly. Sug­ gestions on how to produce Leoti grain for the starch industry call for planting only seed proved by chemical test to have pure waxy endosperm, avoiding cross-pollination by other sorghums, and treating sorghum seed for control of kernel smut. C. Formaldehyde and other Low-molecular Substances: Polymerisation. W . W . Lepeschkin. Kolloid Z., 1943, 105, ,144-147 (through Chem-. A b str., 1944, 38, 4852s). The longitudinal scattering of infra-red rays, which depends on the molecular weight of the scattering substance, was used to determine the degree of polymerisation of formaldehyde, pseudoisocyanin, resorcinol, hydroquinone, and a mixture of pyridine and water. Formaldehyde and pseudoisocyanin became polymerised to high-molecular compounds. The polymerisation of pseudoisocyanin and resorcinol declines upon warming. Alcoholic solutions of pseudoisocyanin are unimolecular. The polymerisation of formaldehyde declines with dilution. . C. Polymers: Formation and Molecular Weight. J. W. Breitenbach and H. Schneider. Ber. dewt. chem. Ges., 1943, 76B, 1088-1095 (through Chem. Abstr.. 1944, 38, 49149). A weakness of the Staudinger method of determining the average degree of polymerization of macro-polymers from viscosity and osmotic pressure measurements is pointed out and the desirability of another independent method is indicated. Earlier experiments with various H-acceptors have shown that an additional “ demolition ” reaction can be introduced into the polymerization process and the average molecular weights of polymers can be reduced in a regular and relatively simple manner. By suitable choice of the conditions it should be possible to obtain such low-molecular polymers that their molecular weights can be determined by the classical methods, preferably the cryoscopic method. From the relationships between these molecular weights and the concentration of the H-acceptor it should be possible to draw definite conclusions as to the molecular weights of polymers which are so high that they can no longer be determined cryoscopically. The results of experiments with styrene showed that the demolition action of chloranil and probably of most other quinones is not satisfactory for this purpose. When o-bromo- benzoyl peroxide was used, the polymers with the lowest basic viscosity were formed at the highest peroxide concentration. Raising the polymerization tem­ perature from 50° to 70° had only a relatively slight influence on the basic viscosity. The following results were obtained in three experiments with 10 x io-3 mol. o-bromobenzoyl peroxide per mol. styrene: polymerization tem­ perature 50°, 50°, 70°; time 5, 75, 1 hour; styrene reacted 29-7, 94-0, 32-4 per cent.; basic viscosity (1 g./l.) 102, 3-61, 0-99 xio-2; molecular weight in freezing benzene 3520, 8200, 3190; Staudinger K m value (basic viscosity/degree of polymerization) 3 02, 4-59, 3■ 23 x io-4. The experimental data are as yet too meagre to derive a relationship between the molecular weight of the poly­ mer and the peroxide concentration, but in principle the object sought may be considered as having been achieved. C. Protein and Cellulose Molecules: Electron Mobility. K. G. Denbigh. N ature, 1944, 154, 642-643. In the light of Mulliken’s suggestion (1939-1941) that C : O groups can give rise to a very energetic type of hyper-conjugation, it would be expected that the polypeptide grid of the proteins in which C : O a 8 6 g— Pure Science bonds are in the i : 5 positions would have an appreciable electron mobility over the full length of the molecule and along the axis of the protein fibre. Opportunities for such conjugation are much smaller in cellulose and vegetable fibres should therefore display lower electrical and optical activity and higher chemical stability than protein fibres.' C. Sodium Stearate: Soap-boiling Equilibria. J. W. McBaiu, K. Gardner and R. D. Void. Ind. Eng. Chem.., 1944, 36, 808-810. Ternary systems (soap- sodium chloride-water) have been described in terms of (1) curd fibres, (2) neat soap phase (liquid crystalline soap solution), (3) a similar but separate middle soap, and (4) isotropic solutions with complicated boundaries extending into lye or brine containing almost no soap. It has now been proved by a variety of methods, including direct analyses, that a new waxlike form, termed “ kettle wax phase,” exists in a predominant position in the ternary diagram at soap boiling temperatures even with the highest pure soap, sodium stearate. The boundaries of the isotropic region in the sodium stearate-sodium chloride-water system at temperatures between 70° and 150° C., and the phase diagram for 90° G. are discussed. Only with the highest concentrations of salt are curd fibres of sodium stearate formed at 900 C. C. Synthetic Rubber: Production. B. D ew ey. Chem. and Eng. News, 1944, 22, 1471-1477, 1514. . A progress report on synthetic rubber in the United States is given under the following headings:—basic Situation, status of syn­ thetic rubber and allied programs, adequacy of tyre production plans versus requirements, conversion to synthetic rubber program, scrap and reclaim rubber, man-power, driving speed, rationing, research and development, crude rubber, pricing of synthetics and crude rubber, the Rubber Order R-i, in ter­ change of information with the U.S.S.R., and organisation of the Office of Rubber Director. Rubber production, consumption and requirement statistics, and rayon and cotton tyre cord consumption and supply figures are presented. C. Gases: Dehydration by Solid Adsorbents. R. G. Cappell, E. G. Hammer- schmidt and W. W. Deschner. Ind. Eng. Chem., 1944, 36, 779-784. A report is given of a study of the use of silica gel, activated alumina grade A, florite (a natural bauxite), and Hi-florite (florite impregnated with 12-14 Per cent, manganous chloride) for the dehydration of commercial gases. Determinations of adsorptive capacity under conditions obtaining in a commercial installation and laboratory tests of adsorptive capacity showed that the adsorptive capacity of all solid adsorbents declines with continued use and reactivation. Oil vapours, hydrogen sulphide, non-volatile compounds and other impurities in the gases cause deterioration of the adsorbents and heating of the adsorbents in dry air causes them to lose adsorptive capacity slowly. Temperature, pressure, specific heat and molecular weight affect the dehydration of gases by means of solid adsorbents. The effects of these variables, and the performance and design of dehydrating installations are discussed. The pressure drop through adsorbent beds and the reactivation heat requirements are studied. C. Fibre-forming Polymers: Chemical Constitution and Colloidal Structure. W. Broser, K. Goldstein and H. E. Kruger. Kolloid Z., 1943, 105, 131-141 (through Chem. Abstr., 1944, 38, 4852'). On the basis of the arrangement of the atoms in the molecule and the state of inner molecular bonding, the fibre- forming, fully synthetic high polymers can be divided into (a) the polymerised hydrocarbons and their derivatives as well as the polymerised ethers (poly­ styrene, polyvinyl chloride, polyethylene oxide), and (b) the “ mesomeric ” chain polymers in which mesomeric groups (amide, ester, urea groups) are part of the main chain structure. The term “ meta-amphoteric ion ” is used to designate the existing intermediate states of these mesomeric groups. The intermolecular bonding state is established from the chemical constitutional formulae, taking steric relations into consideration. In the polymers of group (a) essentially undirected dispersion forces are active, resulting in a " cotton pad ” structure without marked order, whereas in the mesomeric chain poly­ mers essentially directed dipole forces result in a micellar structure with marked autonomous arrangement. The designation “ meta-ion relation ” is given for the intermediate bonding state of the meta-amphoteric ions of the mesomeric chain polymers. It is shown that the common colloidal structure, and there­ with the similarity of the physical properties, of the various mesomeric chain 9— Pure Science polymers have their origin in their common “ meta-ion relation.” Thus the latter accounts for the similarity in chemical constitution. It is proposed that the term “ hydrogen bonding ” should not be used for the intermolecular bonding state between H and N in mesomeric chain polymers. Also here the meta-ion relation should prove more suitable, particularly in reference to the possible intermolecular mesomers. C. Soap Solutions: Foam Stability. G. D. Miles and J. Ross. /. Phys. Chem., 1944, 48, 280-290. The foam stabilities of soap solutions have been compared by means of the pour foam test and the effect of alterations in p H on relative foam stability has been examined for o • 1 per cent, solutions of Na caprate, laurate, myristate, palmitate and stearate. Relative foam stability as a function of concentration has been measured at 57 0 C. for solutions of Na caprate, laurate, myristate, palmitate, stearate, undecylenate, oleate, elaidate, and ricinoleate at the p H where each solution showed maximum foam. The p H range associated with the maximum foam stability for these soaps as a function of concentration has been determined at 57° C. The influence of Ca and Mg soaps on the foam stability of solutions of the corresponding Na soaps and the effects of temperature on foam stability have also been studied. The results are given in tables and graphs and are briefly discussed. Foam stability/con­ centration curves obtained at p H values giving the highest foam stability show the customary increase in over-all stability or surface activity usually asso­ ciated with increasing molecular weight in a homologous series. The probable effects of hydrolysis of the soap and the stabilizing effect of fatty acids on foams are considered. It was found that lauryl alcohol would stabilize the foam of c i per cent. Na laurate solutions at p H 10 and lauric, myristic, or palmitic acid would stabilize the otherwise unstable foam of 0-2 per cent, sodium decyl sulphate solution at p H 4. In contrast to the behaviour of Na laurate, Na palmitate solutions could not be acidified below p H 9-5 without loss in foam stability. Increase of temperature lowers the p H range for maxi­ mum foam stability. Variations in p H appear to affect the foam stability of solutions of mixtures of soaps less than solutions of the individual soaps of which they are composed. As a rule, Ca and Mg soaps are not foam breakers in solutions of Na soaps. Certain exceptions to this appear among the Ca soaps of the unsaturated fatty acids. C. Lower A lkyl Sulphonic Acids: Diffusion. M. E. L. McBain. /. Phys. Chem., 1944, 48, 237-241. Diffusion data are presented for the lower alkyl sulphonic acids with 2, 5, 7 and 9 C atoms in the chain. The diffusion/concentration curves do not show the characteristic minima of'colloidal electrolytes, but are smooth curves showing a drop from high values at infinite dilution. Except at great dilution, the curves lie between those of potassium chloride and sucrose. The lower alkyl sulphonic acids thus resemble half-stro'ng electrolytes. Measure­ ments of the diffusion of octyltrimethylammonium bromide, w-hydroxydecanoic acid, £-trimethylpentadecabetaine, and other large molecules are also reported. The values indicate that even large long molecules roll into spheres when given an opportunity to diffuse, and that the separated charges on zwitter-ions are accompanied in diffusion by free gegen-ions. C. Colour Tolerance: Specification. Dorothy Nickerson and K. F. Stultz. /. Optical Soc. America, 1944, 34, 550-570. The need for a specification of colour tolerance is discussed and the use of a general small-difiEerence formula that can be applied to all colours is considered. It is pointed out that a general expres­ sion must involve judgments of “ equality of colour difference ” anu must depend therefore upon colour scales that have visually uniform colour spacing. A report is given of a study of small colour-difference formulae in terms of the attributes of colour perception, hue, lightness and saturation, and those characteristics of light that are their correlates, dominant wave-length, luminous reflectance, and purity. C. Phase Difference Microscopy. O. W. Richards. N ature, 1944, 154, 672. If a transparent, uncoloured material (glass fibre, plastics, frog epithelium, etc.) includes regions that differ in refractive index, phase differences will be set up in a beam of light passing through the specimen. These differences can be rendered visible by means of a “ phase plate,” which can be selected so that the detail in the specimen appears either brighter or darker than the surround­ ings. The Spencer Lens Co. can supply sets of such plates for insertion into a 88 9— Pure Science- the condenser of the microscope at its back focal plane. They may be mounted on a disc for successive rotation into place within the objective. Advantages are discussed. C. Photo-electric Photometers: Properties, Use and Maintenance. J. S. Preston. Trans. Ilium. Eng. Soc. (London), 1943, 8, 121-152. A comprehensive review of the problems arising in the application of emission photo-cells and selenium rectifier photo-cells to photometry, based on 10 years’ experience at the National Physical Laboratory. The subjects include (1) the difficulties of securing a close approximation to a linear scale, and to the spectral sensitivity of the standard eye, (2) the life, stability and fatigue of photo-cells, (3) the temperature coefficient, (4) the dark .current, (5) the non-uniformity over the area of the sensitive surface, (6) stray radiation, (7) the use of photo-electric instruments for measuring fluctuating light sources, (8) the response of rectifier cells to oblique illumination, and (9) the size of cell best suited to a given purpose. Colour correction filters for use with both types of photo-cell are cited. The principles and methods of use of standard types of photometer circuits are described and critically discussed. A new portable emission-cell photometer is described in which the amplifier circuit, comprising two stages of D.C. ampli­ fication, includes an electrometer tetrode and gives a current gain of 2 x io7 with sufficient stability for measuring photo-currents down to 2 x io-14 amp. to within + 5 p e r ceht. C. Automatic Electric Balance: Development and Theory. J. B. Bratt and K. C. W right. Phil. Mag., 1944, [vii], 35, 588-600. The authors develop the theory of the various circuits employed in the design of an automatic electric balance having (1) high stiffness with corresponding good frequency response, (2) negligible phase shift, and (3) constant, linear calibration. Displacements of a coil in a magnetic field are made to alter the amount of light falling on a photo-cell, and this by means of a simple, single-stage D.C. amplifier controls the current flowing through the coil. It is thought possible to construct a balance with the following characteristics: Load capacity +5 lb., static stiff­ ness 10,000 lb. per in., mass of coil and attachments 4 lb., natural frequency 200 cycles per sec., phase shift between load and current at 20 c.p.s. less than o-i°, output per lb. load io milliamps., frequency response at 20 c.p.s. 1 per cent. high. The balance is intended for use in research on aerodynamic stability, for example in the measurement of wing flutter. C. Cellulose Acetate and Polystyrene Foils: Electric Current Caused by Diffusion of Water. C. Fischer and F. H. Muller. Naturmissenschaften, 1942, 30, 604 (through Chem. Abstr., 1944, 38, 4851s). Foils of organic material, cellulose triacetate or polystyrene, were used as membrane, one side being in contact with saturated water vapour, the other with a vacuum. The evacuated side of the foil was connected to an electrometer. Diffusion into the foil actually is accompanied by a charging current density of the order of io-14 amps. The current density increases rapidly at first, then drops off to a low value and slowly continues to decrease (1 hour). C. Amylose, Amylopectin and Whole Starch Triacetate Films: Properties. R. L. Whistler and G. E. Hilbert, hid. Eng. Chem., 1944, 36, 796-798. Films of amylopectin triacetate and whole starch triacetate are weak and brittle. Amylose triacetate forms films of good strength and flexibility which are optically isotropic and exhibit good fold resistance. Curves are given showing the effect of plasticizer (dibutyl phthalate) on the strength and extensibility of such films, and strength and extensibility data are tabulated for films con­ taining various other plasticizers. Stress-strain curves for amylose triacetate and cellulose triacetate films containing various amounts of dibutyl phthalate, and various properties of the two types of films are compared. A general similarity in such properties as tensile strength, refractive index, density and melting point is noted. The amylose triacetate film has considerably greater inherent plasticity. In general, plasticizers found applicable to cellulose acetates are applicable to amylose triacetate, although the latter requires only 10-20 per cent, plasticizer to give an adequately plasticized film, whilst com­ mercial cellulose triacetates usually require 20-40 per cent. C. Coal and Dyes: Structure and Coking. H. L. Riley. D iscovery, 1944, 5. 273-276, 283. The formation of coal is briefly described and the results of X-ray studies of the structure of graphite, carbons, chars prepared from cellu­ 9— Pure Science lose, starch, wood, etc., and bituminous coal cokes are discussed. The bitumen in coal is responsible for systematic variations in the magnitude of the c dimen­ sion of the crystallites formed on carbonisation and for the coking properties of coal. Several vat dyes give c dimension curves almost identical with those of coking coals, and some of the dyes, e.g. dibenzanthrone (Caledon Deep Blue), on carbonisation form cokes which are very similar to those produced from bituminous coals. The conclusion is drawn that the bitumen part of a bituminous coal consists of large, disc-like aromatic molecules, similar to, but possibly considerably larger than the dibenzanthrone molecule, and capable of slipping one along another under the influence of thermal vibration. C. Rubber: Structure. India-Rubber J., 1944, 107, 288. Electron microscope studies of fine fibres of rubber have revealed two types of structure. The first consists of single thread-like filaments, along which are strung rounded nodules. Both thread and nodules consist of rubber molecules. In the nodules, the groups of chains are bound by so little cross-linking of one chain to another that they may slip freely over and about each other, so freely that the nodule may be referred to as " fluid.” The second kind of structure is a highly branched network, criss-crossed and cross-linked into a tight meshed maze, with fine beadlike knots of material strung along the meshed fibres. The molecules making up these beads are packed far more closely than are those composing the nodules of the first type of structure and they are cross-linked to each other. Consequently, they cannot slip about each other freely, and rubber in which this second structure predominates is therefore far tougher and more resilient than is the softer, putty-like rubber composed principally of the nodular structure. The sol fraction of natural rubber consists mainly of nodular structures of the first type. The gel fraction consists entirely of the beaded networks of the second type. Vulcanised rubber consists almost wholly of gel structures. The milling of natural rubber breaks down the gel portion and increases the sol portion. The vulcanisation process increases the gel portion and reduces the sol portion. C. Vulcanized Rubber: Network Structure and Elastic Properties. P. J. Flory. Chemical Review's, 1944, 35, 51-75. Current concepts of the network structure of vulcanized rubber are reviewed and various recent theoretical treatments of the problem of rubber elasticity are compared and found to be in essential agreement. The theoretically derived equation for the elastic retractive force in stretched rubber consists of two factors, one of which is a function of the relative length alone, whilst the other is proportional to the “ effective ” num­ ber of cross-linkages in the network and is independent of the deformation. (The latter factor also contains the absolute temperature.) Experimental results are in agreement with this separability of the elongation and structure factors; i.e., the shape of the stress-strain curve (short of the region of crystal­ lization) is preserved as the effective number of cross-linkages in the vulcanizate is varied. The observed magnitude of the retractive force at a given elongation is appreciably greater than that calculated from the independently estimated number of chemical cross-linkages in vulcanizates of Butyl rubber. This dis­ crepancy is believed to be due to entanglements of the chains which increase the effective number of cross-linkages. The observed effect of the molecular weight of the rubber before vulcanization on elastic properties of the vul­ canizate is taken into account by an extension of previous theories. The “ flaws ” introduced into the network by the ends of the molecules of rubber diminish the effective number of cross-linkages. The theoretically derived factor which expresses this dependence on initial molecular weight is in good agreement with experiment. The swelling capacity of vulcanized rubber in solvents, like the elastic modulus, is related to the number of effective cross- linkages. Hence, modulus and swelling capacity can be related to one another. The equation expressing this relationship is amply confirmed by experimental results. From this it is concluded that the same cross-linkages are effective in the presence of solvents which swell the rubber as are operative in the reaction of the rubber to elastic deformation. C. Fluorescence of the Skin and Hairs of Trichosurus vulpecula. A. Bolliger. Australian J. Sci., 1944, 7, 35. Examined in a darkened room under ultra­ violet light, most of the skin, hairy or otherwise, of Trichosurus vulpecula, th e grey or common Australian opossum, shows a marked sky blue fluorescence. A g o io— Economics

The fluorescent compound is probably present in the skin secretions as well as in the upper layers of the skin itself. The hair also show fluorescence, the colours differing according to the parts of the body. W. Integument of Mammals: Uric Acid Content. A. Bolliger and M. H. Hard}'. Australian J. Sci., 1944, 7, 59-60. Crystals present in the lumen of the sudori­ ferous glands of the sternal skin of the male common Australian opossum were suspected to be urates from the alkaline secretion of the sweat glands, and uric acid and urates were found in the hairs and hair root sheaths by staining tests. Samples of the entire integument and of skin and hairs separately of various mammals were extracted with water and the total uric acid content of the extracts wetermined by Folin’s colorimetric method (/. Biol. Chem., 1930, 86, 179). The values for hairs were as much as 10 times as high as those for skin, weight for weight. Sheep’s wool contained 20 mg. per cent. This finding will influence future studies of purine metabolism. W. A Reversible Contraction Phenomenon in Animal Hairs. C. S. Whewell and H. J. Woods. N ature, 1944, 154, 546. Wool fibre (Lincoln) immersed in a solution prepared by dissolving purified copper hydroxide in concentrated ammonia solution, is stained greenish-blue and contracts in length after a time depending on the copper content of the solution. A contraction of 28 per cent, of the initial length can be obtained. Prolonged washing in water fails to remove the stain and has little effect on the length. The stain disappears and the fibre returns practically to its original length after leaving for a few minutes in a dilute sulphuric acid solution, subsequent washing in water producing no further change in colour or length. The dimensional changes are accompanied by changes in the X-ray photograph, which becomes weaker and vaguer with­ out loss of orientation or pronounced spacing changes, until, when the con­ traction is a maximum, it has almost disappeared. The amount of copper adsorbed with maximum contraction is about 29 per cent., corresponding approximately to 1 copper atom per 2 amino-acid residues. The contraction may be attributed to the powerful attraction of the copper for the appropriate active groups of the keratin complex. A similar phenomenon has been observed in fibres treated with solutions of some, but not all, related copper compounds. W. Lanthionine: Isolation from Wool. A. Schóberl. Ber. deut. chem. Ges., 1943, 76 B, 970-979 (through Chem. Abs., 1944, 38, 3252). The presence of lanthionine has been verified in wool keratin whose S.S. unions have been extensively altered by treatment with ammonium hydroxide, sodium carbonate, sodium sulphide and sodium hydroxide (cf. these A b s., 1944, A 182 and A 543). The pyridine method of Horn, Jones and Ringel was used (these A b s., 1941, A 245). L a n ­ thionine was separated from cystine by 2 methods, one based on the fact that dibenzoylcystine forms a difficulty-soluble sodium salt (see B er., 1943, 76 B, 964; Chem. Abs., 1944, 38, 3252), and the other based on the specific reaction of the S.S. group in cystine with potassium cyanide. Full experimental details are given. W. P a t e n t s Soluble Starch: Production. M. D. Rozenbroek (Netherlands; vested in U.S. Alien Property Custodian). U.S.P.2,338,457. Powdered starch contain­ ing 8-20 per cent, of moisture is mixed with about 15 parts by weight of sodium carbonate and then treated with chlorine gas at a temperature below 6o° C. The amount of chlorine passed in is about 6 per cent, of the weight of starch . C. Carbamylethyl Cellulose Ester: Production. Rohm & Haas Co. U.S.P. 2,338,681. Cellulose is caused to react at o —40° C. with acrylamide in the presence of a strong base (10-40 per cent, aqueous solution) until carbamyl­ ethyl groups are introduced into the cellulose and some part of them have been further hydrolyzed to carboxyethyl groups. At least 0 2 mol. of acrylamide is used for each glucose unit. 10—ECONOMICS Research and the Future of Wool. A. M. Stewart. J. Australian Inst. Agric. Sci., 1944, 10, 69-75. The problem of assessing the future of wool requires intimate knowledge of textile technology, industrial chemistry, agriculture and economics. Clunies Ross’s proposals for research in Australia on biological problems and on processing and manufacture (see this /., 1944, A 279) are 11— Industrial Welfare, Industrial Psychology and Education A91 critically examined. Distribution costs are the greatest impediment to sub­ stantial reduction in the price of wool goods to the consumer. A central institute should undertake economic and technical research in Australia, leaving biological research to existing organisations, e.g. the Council for Scientific and Industrial Research. W. 11—INDUSTRIAL WELFARE, INDUSTRIAL PSYCHOLOGY, AND EDUCATION Cotton Operatives: Management. M. H. Winder. Textile Weekly, 1944, 34, 910-912, 958-961. A report of a lecture on modem problems of labour management and welfare work in cotton mills. C. Eye Injuries: Prevention in Industry. R. M. Dickson. Brit. ]. Physical Med. &■ Indust. Hyg., 1944, 7, No. 3, 77-83 (through Bull. Hygiene, 1944, 19, 696). The difficulty in persuading those engaged in hazardous occupations to adopt protective measures is well known. Guards and transparent screens may be fitted to lathes, grinding stones and emery wheels, but they are frequently discarded. An ingenious safeguard is the fitting of a shaded light to the under side of the protective screen, because the worker cannot see what he is doing unless the safety screen is in the correct position. Pictorial posters drawing attention to works hazards do not achieve very much, but small accident pre­ vention committees in factories and collieries have proved to be effective. This paper gives an account of the many difficulties involved and of the research work sponsored by the Ross Foundation in Edinburgh, of which the author is the Director. The use of soluble sodium sulphacetamide, 10 per cent, solution, as a prophylactic first aid measure is advocated in all types of indus­ try in which there is a danger of injury to the eye. C. Noise: Analysis and Interpretation for Preventive Treatment. J. Indust. Hyg. & Toxicol., 1944, 26, 120-123 (through Bull. Hygiene, 1944, 19, 695-696). It is pointed out that sound-level studies from an acoustical engineering stand­ point cannot be used for accurate estimation of the liability of the workers to occupational deafness and for this purpose the following procedure is sug­ gested:—(1) The calibration of the noise level meter should be checked each time immediately before use. (2) The meter should be held in the hands or placed on a quiet surface while taking readings. (3) The intensity of noise must always be taken in the immediate vicinity of the ear of the operator nearest the noise, with the microphone held at an angle of 90° to the noise source. (4) Noise levels should also be taken at various points within the space involved. Readings should particularly be taken in passages and at points within the noisy area where other people must work. Their exposure to reflected sound is thus determined. (5) The results should be analysed on the basis of noise levels for industrial operations. In the interpretation of the results, the total time and periods of exposure to the noise during a working spell should be taken into account. Distinction should be made as to the type of noise— whether it is continuous or interrupted. The physical state of the worker should also be considered. Persons with chronic otitis media and other active ear disturbances should not be exposed to the additional hazard of loud noise. It is suggested that an important aspect of a preventive programme should be the audiometric examination of entrants into those industries where noise is likely to be a hazard. Further periodical examinations of the selected workers during employment would prevent trouble developing. The use of ear defenders is also recommended and the efficiency of these can be determined by the audiometer. C. Noise: Effects and Reduction. P. E. Sabine. Amer. J. Pub. Health, 1944, 34, 265-270 (through Bull. Hygiene, 1944, 19, 695). The author gives many quotations from the literature about the ill-effects of noise on operatives. Intelligent planning of a plant can do much to reduce noise. The isolation by means of effective shock mounting of heavy machines will reduce building vibrations which are transmitted with almost undiminished intensity through­ out steel and concrete structures. The use of absorbent surfaces is also advocated to cut down the effect of reverberation. In an open space the intensity of sound from a given source falls off rapidly as the distance increases. In reverberant rooms the sound intensity from a single source is almost inde­ pendent of the distance from the source—the sound spreads with little A92 u — Industrial Welfare, Industrial Psychology and Education diminution with distance. Absorbent treatment greatly reduces this spreading effect—an operator working at a noisy machine has the feeling of a relatively quiet surrounding. An example of the reduction of noise in aeroplane engine testing is quoted. The following measures are suggested to combat the noise hazard. Men rather than women should be employed in places where noise is excessive; there should be an allowance of frequent rest periods to relieve the strain of prolonged exposure to noise, and simple ear defenders should be pro­ vided. A plug of cotton wool moistened with vaseline can effect a 15-20 decibel reduction in noise intensity. The importance of noise control in dwellings is discussed. C. Carbon Tetrachloride Poisoning: Occurrence in a Nylon Parachute Plant. W. E. Doyle and C. Baker. Indust. Med., Chicago, 1944, 13, 184, 186, 188, 190 an d 192 (through Bull. Hygiene, 1944, 19, 775). A description is given of an outbreak of illness among 675 workers employed in making parachutes; 137 were affected with abdominal cramp, nausea and vomiting, due to fumes of carbon tetrachloride used for cleaning nylon fabric soiled with machinery oil. Pads of gauze soaked with the solvent were rubbed against the soiled areas. Some 4 gallons of carbon tetrachloride were being evaporated daily into a room 120 ft. wide, 280 long and 15 high. Out of the 137 who fell sick, 135 had been engaged in sewing and cleaning. Prevention lies in getting rid, if possible, of carbon tetrachloride as a solvent. If it is used its fumes must be drawn away by exhaust draught through vents placed at the floor level. Soiling of the nylon fabric should be carefully avoided. Solvent containers should automatically close when not dispensing the solvent. Workers who have to be exposed to risk should drink a quart of milk daily and avoid greasy foods, and their work should be varied by rotation so as to avoid prolonged exposure. C. DDT Insecticide: Toxicological Studies. J. H. Draize, G. Woodard, O. G. Fitzhugh, A. A. Nelson, R. B. Smith, Jr., and H. O. Calvery. Chem. and Eng. N ew s, 1944, 22, 1503-1504. A brief report is given of toxicological studies of the insecticide DDT. [2 : 2-b is (^-chloro phenyl) 1:1; 1-trichloroethane]. The studies included acute and subacute application to the skin of rabbits, rats, guinea pigs and dogs, acute and subacute feeding to rats, mice, guinea pigs and chicks, chronic feeding to rats and dogs, studies of skin irritation and sensitiza­ tion, pharmacological investigations as to the site and mode of action, and gross and microscopic pathology and blood studies of poisoned animals. The following conclusions are drawn from the results. DDT is a poisonous sub­ stance which should be used only after adequate investigations have shown it to be safe for the particular purpose. DDT in solution is absorbed through the skin and it should therefore be handled with care and its use on the skin should be carefully restricted. The wide range of dosage over which toxic signs can be produced in animals shows that it is either irregularly absorbed or irregularly metabolized, thus making it difficult to establish an absolutely safe level for ingestion. DDT in solid form is not readily absorbed through the skin of animals. Small amounts of DDT in the diet will produce toxicity in experimental animals and the safe chronic level appears to be very low. C.

Tetrachloroethane Poisoning: Occurrence. H. A. Coyer. Indust. Med., Chicago, 1944, 13, 230-233 (through Bull. Hygiene, 1944, 19, 775). Tetra­ chloroethane is used as a solvent in dry cleaning in many industrial processes, particularly as a solvent of cellulose acetate. In the last war it was responsible in Great Britain for cases of toxic jaundice before its use was discontinued. It may involve either the nervous or the gastro-intestinal system or both together. Seven cases, one of them fatal, now reported were of the gastro­ intestinal type. Details and autopsy findings of the fatal case are given. There was cirrhosis of the liver, with superimposed hepatitis and severe jaundice; the heart was hypertrophied; a haemorrhagic diathesis was present with bleeding into the gastro-intestinal tract; ascites was usual. The six non-fatal cases, after a short period in hospital, slowly returned to normal. Intramuscular injec­ tions of liver were considered of value, with glucose injections and a high carbohydrate diet. C.

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