Inorganic Chemistry. 539

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INORGANIC CHEMISTRY. 539

Inorganic Chemistry.

Behaviour of Diamond at High Temperatures. By v. S c H R O T T E R (Chem. Centr., 1873, 154). A PERFECTLY transparent and polished diamond, in the form of a rhomb, slightly injured at the edges, was placed in the middle of a Hessian crucible filled with calcined magnesia and covered with a porcelain lid ; this was enclosed in a second crucible, the intervening space being filled with graphite, and the whole was exposed to the highest temperature of a porcelain kiln. After cooling, the diamond was somewhat dull on the surface, but showed no trace of blackening or turbidity within. But on repeating the experiment with the diamond wrapped in platinum-foil, it was found that the platinum, which was fused to a globule, had taken up carbon, and the diamond was totally altered in appearance. The surface was slightly blackened, and the interior exhibited black dendritic markings. The black of this diamond was a pure black, like amorphous carbon, whereas natural black diamonds have always a more OT less dark-brown appearance. The density of the diamond was reduced from 3.48 at 18' to 3.473 by heating in magnesia, and further to 3.458 by heating in contact with platinum. J. R,

Action of Nitrogen Tetroxide on Arsenic Trichloride and on Boron Trichloride. By A. GEUTHER(J. pr. Chem. [el, viii, 334 -359). Published on 01 January 1874. Downloaded 24/10/2014 00:46:33. WHENnitrogen tetroxide is distilled into refrigerated arsenic trichloride, it forms a liquid stratum floating on the chloride, and a small quantity of a white solid substance was observed at the line joining the two fluids. The two liquids were now mixed, and the whole was allowed to stand for some time at a temperature of about 0". Under these circumstances the white substance was formed in considerable quantity, and nitrogen dioxide was slowly evolved, the whole being, at the end of 36 hours, converted into a crystalline mass saturated with a reddish-yellow fluid. The solid portion consisted essentially of arsenic acid, which was contaminated with a trace of arsenious acid, this latter probably arising from the action of moisture on a portion of the arsenic trichloride ; while the fluid portion consisted of riitroxyl chloride, NOCI. Probably the reaction is as follows : 4AsC13 + 5NzOa = 2Asz05 + 8NOC1 + 2NOC1,. There appears to be no tendency towards the formation of the oxychloride, AsC1,O. View Article Online

540 ABSTRACTS OF CHEMICAL PAPERS.

When boron trichloride is similarly treated with nitrogen tetroxide, an energetic action takes place, a solid substance being deposited in the liquid, while yellow crystals condense on the sides of the flask. The product was left at rest for two days, after which it was distilled at a gentle heat. Under these circumstances volatile yellow crystals con- densed in the receiver, and the brownish-red vapour of these crystals fumed on coming in contact with the air. A liquid which appeared to be a solution of the crystals in boron trichloride also passed over. The crystals had the composition BCl,.NOCl, and form rhombic octohe- drons or prisms which dissolved in water with a hissing sound, boric acid, nitric acid, and chlorine being produced. At 23"-24' the crystals melt, forming two layers of fluid, the upper of which appears to consist of boron trichloride containing a small proportion of the original substance, while the lower probably consists of the fused substance together with a small proportion of nitroxyl chloride. On cooling, the two layers reunite with more or less rapidity, according to circumst.ances, the original substance being reproduced. The reaction is probably as follows :- 8BC1, + 3NZOa = B203 -I- 6(BC13.NOC11) + 0,. T. B.

Action of Phosphorus Chlorides on the Acids of Phosphorus. By A. GEUTHER(J. pr. Chem. [2], viii, 359-372). 1. Action of Phosphorus Oxychloride on Orthophosphoric Acid.-When these substances are mixed in accordance with the equation, @OaH, + POCl, = 3P03H + 3ClH, no reaction takes place until the mixture is heated in the water-bath, the reaction then proceeding as above in- dicated. The use of a smaller proportion of phosphorus oxychloride Published on 01 January 1874. Downloaded 24/10/2014 00:46:33. leads to the formation of pyrophosphoric acid : 5POkH3 + POC13 = 3P207H4 + 3HC1. As, however, the author finds that pyrophosphoric acid is produced when metaphoephoric acid and orthophosphoric acid are heated together, it is probable that in the above case the pyrophosphoric acid may result from a secondary reaction between metaphosphoric acid and orthophosphoric acid. 2. Action of Phosphorus Pen€achloride on Orthophosphoric Acid.-The following reaction takes place in the cold : P04H3 + 3PC& = 4POC1, + 3HC1; but if excess of phosphoric acid is employed, the action recommences on the application of heat, the phosphorus oxychloride then acting on orthophosphoric acid according to the equation previously given. 3. Action of Phosphorus Trichloride on Orthophosphoric Acid.-When a gentle heat is employed, the principal reaction appears to be it5 follows : 3PO4H3 $- PCI, = 3PO3H + P(OH), + 3ClR, View Article Online

INORGANIC CHEMISTRY. 541 but free phosphorus and pyrophosphoric acid are produced, probably owing to secondary reactions. 4. Action of Phosphorus Pelztachloride om Metaphosphoric Acid.-The reaction, P03H + 2PC1, = 3POcl3 + ClH, takes place when these substances are heated on a water-bath ; and even when a small proportion of pentachtoride is employed, the reaction is the same, no chloride of metaphosphoric acid being produced. Metaphosphoric acid is not attacked when digested with phosphorus oxychloride or phosphorus trichloride. 5. Action of Phosphorus Pentachloride, Phosphorus Trickloride, and Phosphorus Oxy chloride on Pyrophosp horic Acid.-T he following reactions take place on the application of heat :- (1.) P207H4 + ~~CIS= 7Poc1, + 4C1H. (2.) 9Pz07H4 + 5PC& = 21P03H + 2P + 15HCI. (3.) 2Pz07H4 + POCI, = 5PO3H + 3C1H. When pyrophosphoric acid is treated with a small proportion of phosphorus pentachloride, the reaction is-

P207H4 + PCl, = 2PO3H + POCI3 + 2ClH. 6. Action of Phosphorus Oxychloride and Phosphorus Pentachloride on Phosphorous Acid.-The reactions being as follows, it is concluded that the true formula for phosphorous acid is P(OH),, and not PHO, (OH), : (I.) 3POCI3 + 2P(OH), = 3PO3H + 2PCI3 + 3ClH. (2.) P(OH), + 3PC1, = PCl, + 3POcl3 + 3HC1. 7. Action of the Chlorides of Phosphorus on Hypophosphorous Acid- Phosphorus trichloride acts energetically on hypophosphorous acid, the reaction being apparently as follows : Published on 01 January 1874. Downloaded 24/10/2014 00:46:33. 3PH(OH)2 + PCI3 = 2P(OH)3 + 2P + 3ClH. Orthophosphoric acid is also produced, but this probably arises from the action of phosphorus trichloride on phosphorous acid. These results indicate P"' (OH)z as the formuIa of hypophosphorous acid ; all attempts to obtain 1"the chloride of this acid were fruitless. The action of phosphorus oxychloride is similar to that of the trichloride, but the reaction is more energetic, and after it has ceased, a fresh reaction may be produced by heating the mixtbre to 100". The two stages may be represented as follows :- (1.) GPH(OH), + 3POC1, = 3P03H + 2P(OH)3 + 4P + 9ClH. (2.) 2P(OH)3 + 3POC1, = 3P03H + 2PC13 + 3ClH. The former reaction is probably the resultant of the following :- (a) GPH(OH), = 2PH3 + @(OH),. (b) 4P(OH)3 + 3POC1, = 3PO3H + BPC13 + 3C1H + 2P(OH)3. (c) 2PH3 + 2PC13 = 4P + GHCl. View Article Online

542 ABSTRACTS OF CHEMICAL PAPERS. Hypophosphorous acid thus behaves like a mixture of PH, and P(HO),, and it was found that when it is heated to 110"-115", it is decomposed into these substances, but when the heat reaches 2-50" the phosphorous acid decomposes. The action of phosphorus pentachloride on hypophosphorous acid is energetic, red phosphorus being deposited ; but after sufficient of the pent'achloride has been added, and the mixture has been heated, nothing remains but phosphorus oxychloride and phosphorus trichloride. The reactions are probably as follows :- (1.) SPH(OH), + GPC1, = GPOCI, + PCl, + 2P + SHCI. (2.) GPH(OH), + 6POC1, = 6P03H + 2PC1, + 4P + 12HC1. (3.) 6PO,H -+ 12PC1, = 18POC1, + GClH. (4.) GP + 9PCI5 = 15PC13. ultimate result : PH(OH), + 3PC1, = 2POC1, + 2PC1, + 3HC1. T. B.

Phosphorus Sulphobromide. By R. W. EMERSONMACIVOR (Chemical News, xxix, 116j. A DESCRIPTION of the properties of the compound first prepared by Baudrimont, by passing sulphuretted hydrogen through phosphorus pentabromide. The reaction is as follows :- PBr6 + H,S = PBr,S + 2HBr. The undecomposed pentabromide is removed by washing with water heated to about 40". G. T. A.

Published on 01 January 1874. Downloaded 24/10/2014 00:46:33. Action of Silver Chloride on Phosphorus Di-iodide. By A. GAUTIER(Compt. rend., lxxviii, 2%-288). THISreaction is not, as might be supposed, 6AgC1 + 3P1, = 3PC1, + GAgI, but GAgCl+ 3P1, = 2PC1, + 6AgI + P. It begins in the cold. B. J. G.

Action of Heat on Mixtures of Calcium Phosphate and Cal- cium Carbonate. By F. WIBEL(Deut. Chem. Ges. Ber., vii, 220--225). WHENmixtures of calcium carbonate and calcium phosphate arc heated, either in the presence or absence of organic mittec carbonic anhydride is driven off, and treatment with ammonium carbonate does not restore the whole of the carbonic anhydride thus lost. Conse- quently the usual process for determining the mineral constituents of bones or semi-mineral phosphates gives results which are too low. If calcium pyrophosphate is heated with one-sixth of its weight of calcium carbonate, organic matter being either present or absent, View Article Online

INORGANIC CHEMISTRY. 543

the amount of carbonic anhydride not restored by ammonium carbonate amounts to 67-3-69.3 per cent. of the whole, and the pyrophosphate tends to become converted into orthophosphate. When calcium orthophosphate is heated with chalk, and the product is treated with ammonium carbonate, the loss of carbonic anhydride is less than in the previous case, there being a tendency towards the formation of the compound 5Ca3P,O8 + CaO ; and when artificial apatite, 4Ca3P20s, CaCl,, is in like manner heated with calcium carbonate, the CaCI, is replaced by CaO, a substance having the composition 4Ca,P20s.Ca0 being produced. These results indicate the necessity of determining the carbonic anhydride in mineral phosphates before ignition ; and as bones coni- port themselves like a mixture of calcium orthoph3sphate, calcium carbonate, and organic matter, there is no reason to assume that they contain a substance possessing the composition 3Ca3P208.CaO, as sug- gested by Aehy. T. B.

Crystallisation of Supersaturated Solutions of Sodium Sul- phate. By D. GERNEZ(Compt. rend., Ixxviii, 283-286). THEphenomenon adduced by Coppet (p. 337), as proving the exist- ence of two niodifications of anhydrous sodium sulphate, was long ago pointed out by the author (Compt. reizd., lx, 833), who, however, disputes Coppet's conclusions. The air-dried salt very possibly retains a trace of water inappreciable by the balance. This trace would, he thinks, be sufficient (see this Journal [Z], xi, 721) to crys- tallise a supersaturated solution. This idea is confirmed by the fact that the solid 7-atom salt, which throws down from a supersaturated solution the '/-atom hydrate only, will act in the same way after

Published on 01 January 1874. Downloaded 24/10/2014 00:46:33. being air-dried. Coppet would scarcely maintain that there was a third modification of the anhydrous sulphate derived from the 7-atom salt. The anhydride produced by heating the 10-atom salt above 33" also throws down the "-atom salt from a supersaturated solution, but it does so much more slowly than the air-dried 7-atom salt does; in fact it has first to be converted into the 7-atom salt, a conversion which always takes place when the anhydride is submitted to the action of water-vapour, and, therefore, it is argued, of the water of the supersaturated solution. B. J. G.

The Crystallisgtion of Glass. By EUG.PELIGOT (Cornpt'. rend., lxxviii, 386-392). IN a factory at Blanzy 12,000 kilos. of glass (for bottle making) are melted at one operation, in a gas-furnace. An accident having rendered it necessary to draw off the still fluid portion of the charge after a part had already solidified, some crystalline nodules were fount1 in the lower part, and were submitted to analysis, together with their mother-liquor and some of the normal glass from tlie same charge. View Article Online

544 ABSTRACTS OF CHEMICAL PAPERS. I. 11. 111. Mother-liquor. Devitrified glass Transparent Normal in crystals. glass. glass. Silica ...... 62.3 61.8 62.5 Lime ...... 22.7 21.5 21-3 Magnesia...... 8.4 5.4 5.6 Oxide of iron ...... 3-2 3.0 3.0 Alumina ...... 2.5 2.1 2.1 Soda...... 0.9 6.2 5.5 Among the nodules were found distinct crystals having a length of 20 to 30 mm., which M. Des Cloizeaux recognised as having the form of pyroxene. On comparing the analysis of this devitrified glass with that of pyroxene and amphibole, there is seen to be a certain resem- blance, and the author considers that devitrification is caused by the crystallising out of compounds analogous to those minerals from the fused or pasty mass of heated glass, and accounts for the fact that “ RBauniur’s porcelain ” and t8he glass from which it proceeds have the same weight and composition, by remarking that as no separation of crystlals and mother-Iiquor can take place, the whole mass must retain its original constitution. That the glass has really become converted into a mass of crystals of one composition imbedded in a matrix of another is, he considers, proved bv the fact that devitrified glass sweats in a damp atmosphere,land giv& up alkali to water. C. H. G.

On Porcelain and some Allied Products of Devitrification. By H. BEHRENS(Pogg. Ann., cl, 386-399). PORCELAINis generally regarded as the product of the partial fusion of its constituents, its opacity being due to unmelted particles of kaolin, the Published on 01 January 1874. Downloaded 24/10/2014 00:46:33. aggregates of which are rendered translucent by tJhe glassy nature of other con8tituents which have undergone fusion, like paper soaked in varnish. According to this view it would become transparent if exposed to a temperature sufficiently high to melt the kaolin. G. Rose, however, from experiments on the diminution of the density of porcelain when exposed to high temperatures, was led to believe that the kaolin does not remain unaltered in the fused materials, but enters, at least, partially, into combination with felspar. The author finds that such is the fact. Microscopic examination of porcelain with sufficiently high powers shows that the kaolin has always undergone com- plete fusion, the only constituent of the porcelain which has partially retained the solid form being quartz. But the edges of the quartz particles are invariably rounded, and in certatn kinds of hard porcelain no trace of quartz can be discovered, though such specimens exhibit in other respects precisely the same appearances under the microscope as porcelain containing unfused quartz. Porcelain is one of the most difficult of microscopic objects, as re- gards both the preparation of specimens and their examination under the microscope. It. must be ground to exceedingly thin plates, which require to be highly polished and examined with the very View Article Online

INORGANIC CHEMISTRY. 545

highest powers under the most favourable conditions of illumination. The author employed an immersion-objective, magnifying 3,000 diameters. Under this power, porcelain exhibits an immense number of minute colourless crystalline rods (Zirkel’s beZonites) with smooth edges, crossing each other in all directions. Between these are seen still smaller roundish granules, frequently so close together as com- pletely to cover the glassy mass which forms the basis of the porcelain. One specimen (from the lid of a Berlin crucible) exhibited here and there bright spots containing neither belonites nor granules. Possibly in these places the fusion of quartz particles had rendered the glass un- crystallisable from excess of silica. Other specimens showed the quartz particles mentioned above. Besides these constituents, such specimens exhibit only minute air-’bubbles, varying considerably in size and form. By treating thin plates of porcelain with dilute hydrofluoric acid, which dissolves the crystallised constituents much less rapidly than the quartz and glass, the author succeeded in obtaining specimens in which the dimensions of the belonites could be approximately measured, and their form and arrangement more clearly perceived. The belonites have sometimes rounded, sometimes obliquely truncated ends, in the latter case closely resembling microliths of felspar, but much smaller. Some have forked ends, resembling hornblende microliths. Frequently the crystals are arranged side by side in bundles which cross each other in all directions, forming a network, in the meshes of which lie the granules mentioned above. Some of these graiiules are spherical, others are elongated: they occur both singly and in groups. They have the same diameter as the belonites, of which they might be regarded as fragments, were it not that they occur in natural and artificial deetriiied masses in which no crystals are found. The glass of wine-bottles is readily devitrified. When heated in chalk or powdered coke for an hour and a half to a temperature high enough to round the edges, it is converted into a very hard porcelain- Published on 01 January 1874. Downloaded 24/10/2014 00:46:33. like mass, nearly free from colour. Thin splinters of this, treated with hydrofluoric acid till nearly dissolved, exhibit under the microscope only minute granules, no trace of crystals being visible. Common window glass devitrified by heating for three hours exhibits neither granules nor crystals, but rhornbic tables, which the author has observed also in fused trachyte and in some iavas from Vesuvius. Belonites appear to be formed only in glass rich iu alumina : they are especially abundant and well formed in glassy slags from brick- kilns. A specimen of very thin Japanese porcelain microscopically examined by the author exhibited the same constituents as European porcelain, but in very different proportions. It contained about equal quantities of unfused quartz and belonites, and a decidedly larger proportion of glass. The belonites were well formed, and often collected in bundles and stars, sometimes in tufts like thistle-heads. The quartz particles were but slightly rounded, the air-bubbles large, generally spherical, and very numerous, especially in the very thick glaze. From these characteristics, and a knowledge of its chemical composition, the author deduces the conditions of manufacture of Japanese porcelain. J. R. View Article Online

546 ABSTRACTS OF CHEMICAL PAPERS.

The Effect of Acid on the Interior of Iron Wire. By 0 SBORNE REYNOLDS(Chem. News, xxix, 118). SOMEiron and steel wire which had been acted upon by sulphuric acid was found to have become altered in their properties. Though soft char- coal wire, it had become short and brittle, the weight had increased, and when a specimen was broken and the fractured end was wetted with the mouth, it frothed up as if acted on by a powerful acid. These effects were not permanent. The explanation given by Mr. Johnson, who first observed these phenomena, is not the correct one. They are due to hydrogen which has entered into the iron. The author took a piece of iron tube, and having closed it at one end, immersed it in dilutle sulphuric acid; hydrogen was found to pass through into the interior of the tube, and could be collected by con- necting bhe open end of the iron tube to a glass one by means of india- rubber. It is probable that iron becomes saturated with hydrogen whenever oxidation goes on under water, and if so, the fact of the metal being thus rendered brittle is an important question in the case of iron boilers and ships. G. T. A.

Preparation of Chromic Acid. By 0 s c A R P 1 c IN u s (Arch. Pharm. [3], ii, 23; iii, 305). WARINGTON’Smethod of preparing chromic acid (which consists in mixing 1 vol. of a cold saturated solution of potassium bichromate with 1; vol. of strong sulphuric acid) often fails, owing to the acid employed not being strong enough, in which case no separation of chromic acid takes place. The addition of more sulphuric acid throws down only a small quantity of chromic acid in red flocks. It is better, Published on 01 January 1874. Downloaded 24/10/2014 00:46:33. therefore, to evaporate the liquid over the water-bath till a small portion placed on a watch-glass crystallises on cooling, and then to allow the whole to stand for two days, whereby fine crystals are obtained. When chromic acid is to be prepared frequently, the author prefers to use the residual sulphuric acid from a previous operation; it is then only necessary to evaporate somewhat longer over the water- bath. On using the same acid a third time, a little potassium bisul- phate crystallises out with the chromic acid. For preparing chromic acid once only, 1part of a cold saturated solution of potassium bichromate may be mixed with 1 part of strong sulphuric acid, and the mixture evaporated over the water-bath. In this may a considerable saving of sulphuric acid is effected, whilst the product is as abundant, aiid as well crystallised as that obtained by Warington’s method. The author attempted to prepare chromic acid from barium chro- mate and sulphuric acid, but did not succeed in obtaining a, product crystallised in needles. J. R.