UNITED STATES PATENT OFFICE. HARMON HIBBARD, OF HENRIETTA, ASSIGNOR TO W. W. REID, OF ROCH ESTER, NEW YORK. IMPROVEMENT IN TANNING LEATHER BY TANNIN AND ACIDs. Specification forming part of Letters Patent No. 6,790, dated October 16, 1849; Reissue No. 1 S9, datetl February 11, 1851. To all whon it may concern. Beit known that I, WILLIAM W. REID, of texture are materially injured; but potash, be the city of Rochester, in the county of Monroe ing very soluble, is easily washed or worked and State of New York, assignee of Letters out by water alone; besides it has a greater Patent of the United States granted to HAR affinity for fat or oil, and makes a soluble soap, MON HIBBARD, of the town of Henrietta, in which also is easily worked out; but lime the county and State aforesaid, for certain Im makes an insoluble soap, which is removed provements in Tanning by Tannin and Acids, with more difficulty. Potash, being soluble, which Letters Patent, bearing date the 16th penetrates and softens the hide more speedily, day of October, 1849, were assigned to me on and thus enables the lime itself to act sooner the 23d day of October, of the same year, by than it could alone; but fresh quicklime loos deed, which deed was duly recorded on the ens hair sooner than potash. Thus the two 24th of November, year aforesaid, believing conjoined subserve a better purpose than either that said Letters Patent are inoperative and singly. Salt in solution also aids in softening invalid by reason of a defective specification, dry or hard hides. It protects the substance have surrendered the same, and, according to of the hide from the too caustic action of the the requirements of the acts of Congress in alkalies, loosens dirt, grease, &c., and thereby such case made and provided, have applied purifies the skin. It might be omitted in treat for a reissue of Letters Patent for the same ing salted hides, unless soaked too long in wa improvements under the specification of the ter; but in all cases it preserves the substance words following, viz: and weight of the hides while undergoing the The invention and discovery of HARMON liming process. HIBBARD consists in new and useful improve The nature of HIBBARD's invention, so far ments in the preparing of hides and skins for as relates to the process of tanning, consists in tanning, and in the art or mode of tanning the the use of a composition of salt, sulphuric acid, same, with or without the hair or wool upon and sumac, oak, hemlock bark, or any other them, thereby making leather suitable for the tannin used for tanning: The salt, sulphuric various purposes to which hides and skins acid, and tannin being mixed together in wa thus tanned may be applied. ter, in certain proportions hereinafter men tioned, a portion of the salt is decomposed by First, the nature of his invention, so far as the sulphuric acid, forming sulphate of soda it relates to the preparation of hides and skins and setting muriatic acid free, which, (the . for tanning, consists in the use of a composi muriatic acid,) being absorbed by the water, tion of lime, wood-ashes or potash, and salt, for acts directly and rapidly on whatever of the the purpose of removing hair or wool, and also alkalies may yet remain in the skins, dissolv for the process of “liming,' so called, instead ing and removing them, while it acts with of using lime alone, as in the old method. Lime equal rapidity on the hide itself, “raising' it and ashes or potash, and even salt in weak so or opening its pores, prepares it to receive lution, have been used separately for the pur the tannin, which, being present, also in the pose of removing hair and wool, also for the mixture, immediately unites with the gelatine process called “liming'-that is, for remov of the hide, formingleathermore expeditiously ing grease, mucus, and other impurities from than by the old method. hides and skins, but not as above combined. To enable others skilled in the art of tanning It requires several days, and sometimes weeks, to use this method, let them observe the fol to effect these several objects by the use of lime lowing: For “unhairing and liming,' so called, alone. Moreover, lime being nearly insoluble, and for pulling wool, prepare and use the the hides become impregnated therewith, so following composition, which I denominate that bates and drenches and much labor are “Composition No. 1:’ good wood-ashes, one required to remove it before the hides are in bushel, (or potash about five pounds;) fresh a suitable condition to receive the tannin, in slaked lime, four quarts; salt, about three consequence of which their muscular fiber and quarts; water, about one hundred gallons.

These ingredients may be mixed together and over the acid. If it is considerably more so, the hides be put into the mixture for unhair no harm can accrue; but if the acid should be ing and liming; but for pulling wool, take in excess, injury might be done. There should lime and ashes, equal parts, and salt, one quart be sulphuric acid enough to decompose enough to one bushel of the mixture, and mix with of the salt to liberate an equivalent of muri water sufficient to make a thin paste, which atic acid, of which there should be so much as is to be applied to the flesh sides of the skins is sufficient to give the hides a uniform color in the usual way, and kept at a temperature and cause them to swell or puff up slightly. of 60° to 68° Fahrenheit; or a better method The muriatic acid thus generated by the de may be to bleach the ashes, or, when potash is composition of the salt, by means of the sul used, to dissolve it in the water. To the clear phuric acid, attacks the alkalies that may re lye add the lime and salt, and use this mix main in the hides, dissolves or converts then ture for unhairing and liming; but for pull into soluble muriates of lime or potash, and ing wool mix one bushel of lime and one qualit thus acts as a bate and drench on the hides to of salt with good strong lye, making a thin clean them, while at the same time it opens paste, which apply to the flesh sides of the their pores, so that they imbibe the tannin skins, as already described. A little practice more rapidly. It also precipitates or decom will enable the operator to judge of the prop poses a portion of the coloring-matter of the er strength of composition No. 1. It should ooze, and thereby renders the color of the have a slippery feel and quite a sharp alkaline leather lighter, more lively and beautiful. If taste. It is readily made stronger by addition there is a deficiency of acid, so as not to nell of more material, or weaker by adding water. tralize all the alkalies remaining in the hides, The above quantities and proportions serve as they will be spotted or dark colored. They a general guide. The lime and ashes or potash will not raise or swell up. In such case more may be used in various proportions; but it is of the sulphuric acid must be added for the desirable that as little lime as possible to pro purpose of decomposing more of the salt,(which duce the desired effect should be used, be is supposed to be in excess,) and thus furnish cause of its insolubility and of its insinuating more of the muriatic acid. - itself into the substance of the hide. The Muriatic acid of commerce may be added to hides or skins, having been properly soaked, the tannin and salt, and they will produce softened, and “broken, are to be put into nearly the same result. The sulphate of soda (composition No. 1 in a vat or vats, and handled would be wanting; but this also may be added, in the usual way. The temperature may be and then we should have the same composi kept at 50° to 60° Fahrenheit. As soon as the tion and precisely the same results, and when hair will come freely, they must be taken out economy would warrant it, this course might and put into clean, warm, soft water and soaked be adopted; but at present cost of these ma . several hours, then thoroughly worked, flesh terials it is cheaper to use sulphuric acid and and grain, on the beam, then put back into salt, and thus generate both the muriatic acid the water, soaked again, and worked again and sulphate of soda. This method is also till they are sufficiently “reduced. They are more simple. then ready for the tanning process. As a The hides and skins having been prepared general thing, bates and drenches will not be in composition No. 1, as already described, required, because the potash, being soluble, and they are then to be put into composition No. the little lime used are easily washed out with 2, prepared as above, in suitable vatsandhan Water, and because composition No. 2, about to dled often in the usual way. The strength of be described, used in the tanning accomplishes the composition must be kept up by additions the identical objects to be obtained by bat of strong ooze, and also of salt and acid when ing and drenching. If any prefer, they may necessary, and in such quantities as will give prepare their hides and skins after the old the original taste, color, &c. method. They can be tanned just as well by The time required to accomplish the pro composition No. 2; but skins and hides pre cess of tanning will depend on the quality and pared by the foregoing method will make. size of the hides or skins or kinds of leather to heavier and stronger leather than when pre be made, and on the strength and temperature pared by the old process of liming and bating. of the composition. If the strength be good, For tanning, make and use the following, the temperature about 80°Fahrenheit, and the which I denominate “Composition No. 2:’ handling properly conducted, most kinds of n Take sumac, oak-bark, quercitron, or any other leather may be tanned in less than half the tanning materials, either singly or combined. time required by the old method of tanning Bleach and make a strong infusion or ooze. now in use in our country. When the hides To every onehundred gallons of ooze, add salt, are sufficiently tanned, those designed to be twenty pounds, sulphuric acid, two pints. curried may be curried and finished in the These quantities serve as a general rule. A usual way. If the process has been properly little experience will enable a workman to de conducted, they will require much less scour termine by the color and taste as to the req ing, whereby some hard labor is saved. uisite proportions and quantities and strength When it is intended to black and finish on of the composition without weighing or meas the grain, in order to remove any excess of uring. The salt should always be in excess salt and acid that may remain in them and in

terfere with the finishing, after removing them moon-knife, &c., the same as in oil-dressing, from the vats soak them one hour or less in a but without any oil. clear ooze made of the same kind of tannin In order to-tan hides or skins with fur, hair, used in tanning them, then rinse and strike or wool on, they must first be washed thor them out of clean soft water, after which im oughly clean in a weak potash lye or in soft merse them in the following composition: To soap and water, (care being taken not to keep every gallon of soft water add of good soft them in solong as to start or loosen the fur, &c.) soap one quart; best sperm or cod oil, one pint. then flesh and break them, rinse in clean soft Mix and beat these ingredients welltogether. water, then tan them in composition No. 2. After being dipped in this mixture let them To make white leather sumac should be used sammy or dry partially, then shave, set, and in making composition No. 2. stuff them. For stuffing use common stuffing What I claim, and desire to secure by Let and soft soap, equal parts, or sad and cod oil, ters Patent, is- - equal parts, after which, if to be finished on 1. The process of removing hair and wool the flesh side, proceed in the usual way; but . from hides and skins and of “liming' them, if to be blacked on the grain, wet or sponge so called, preparatory of tanning, by the use of them when nearly dry on the grain side with a composition of lime, wood-ashes or potash, a weak solution of potash or sal-soda, then ap and of salt, called “Composition No. 1,’ in ply a thin coat of blood and acetate of iron as the manner above described. used by morocco-dressers. Let them nearly 2. The use of a composition of lime and wood dry, then repeat the coat of sal-soda and mix ashes or potash without the salt; but I do not ture of blood and acetate of iron, then set them claim either of these materials separately by smooth on both sides, oil and dry them. itself. Deer, sheep, and similar skins designed for 3. The process of tanning hides and skins by buck or imitation of buck-such as are used the use of any kind of tannin, in combination for gloves, mittens, and military trimmings either with the muriatic acid of commerce Or should be “frized' after being prepared in with muriatic acid generated by a mixture of composition No. 1, and unhaired and then sulphuric acid and salt in water with the tan tanned in composition No. 2, prepared with nin, in the manner substantially as above de sumac. When tanned, rinse and strike them scribed. out of clean soft water, then hang up to dry. When dry, finish on a perch with a stake, W. W. RED. moon-knife, and pumice-stone; or, to make Witnesses: them soft and elastic, they may be milled first, DANIEL LEE, before quite dry, and thenfinished with perch, PETER. C. How LE.