INOROANIC CBE MISTRY.In o r g a n i c C h e m i s t r y.215Action of the Induction Spark on Phosphorus Trifluoride.By H. MOISSAN (Compt. rend., 99, 970--972).-When carefully driedphosphorus trifluoride is subjected to the action of induction sparks,the volume of the g m diminishes, and phosphorus is deposited on th216 ABSTRACTS OF CREMICAL PAPERS.sides of the eudiometer. The glass is not attacked, and the gas con-tains no trace of silicon fluoride. When brought in contact withwater, about 6-7 per cent. of the gas is dissolved, yielding a solutionwhich contains phosphoric acid, whilst the residual gas has all theproperties of phosphorus trifluoride. It would seem, therefore, thatthe induction spark partially decomposes phosphorus trifluoride intophosphorus and fluorine, but that the latter at once unites with unde-composed trifluoride, forming phosphorus pentafluoride.If the passageof the spark is continued for several hours, the deposit of phosphorusiucreases, and the volume of the residual gas continues to diminish ;after some time, however, a condition of equilibrium is attained anddecomposition ceases.If the phosphorus trifluoride is not completely dried, but is simplybubbled through strong sulphuric acid and then subjected to theaction of the spark, phosphorus is liberated and the volume of the gasdiminishes, whilst the eudiometer is corroded, and after an hour theresidual gas contains as much as 20 per cent. of silicon fluoride. Thesmall quantity of water in the gas is decomposed by the spark, andthe hydrogen unites with some of the fluorine of the trifluoride,forming hydrofluoric acid, which acts on the glass and thus pro-duces silicon fluoride and water.This water is decomposed in thesame manner, and the same series of reactions again takes place, asmall quantity of water being thus sufficient to convert a relativelylarge quantity of phosphorus trifluoride into silicon fluoride. Thisconversion is, however, never complete, a condition of equilibriumbeing established after some time. The mixture of gases resultingfrom the action of the spark on moist phosphorus t'rifluoride gives adeep blue coloration when brought in contact with potassium iodideand starch. No similar coloration is given by the products of theaction of the spark on the dry gas.Density of Sulphuric Acid.By G, LUNGE (Ber., 17, 2711-2715).-A reply to Mendelheff.Pyrosulphates. By H. SCHULZE (Ber., 17, 2705--2709).-Byheating normal sulpli ates with sulphuric anhydride in sealed tubes,Weher obtained octosulphates (this vol., p. 121); these are con-verted by heat into pyrosulphates. The author finds that manysulphates combine with sulphuric anhydride without the applicationof heat, and that when the excess of anhydride is distilled off a t100-120", pyrosulphates remain more or less pure. Potassium,ammonium, silver, and thallium pyrosulphates may thus be obtainedpure, and also those of the alkaline earths and of magnesium,but the product from sodium sulphate contains only 85 per cent.pyrosulphate.The sulphates of lead, zinc, cobalt, nickel, andmanganese also absorb sulphuric anhydride to a greater or lessextent.Attempts to prepare barium and magnesium pyrosulphates byheating their hydrogen sulphates yielded negative results. Hydrogenammonium sulphate heated at 250-300" gave a product contaming74.44 per cent. SOa (calculated for pyrosulphate, 75-47), BetterC. H. BINORGANIC CHEMISTRY. 217results are obtained by heating sulphates with chlorosulphonic acid(see Schiff, AnnuZen, 126, 168); the author has prepared sodium,ammonium, and barium pyrosulphates in this way.Comparative Oxidation of Solutions of Sulphurous Acidand of Sodium Sulphite. By C. L. REESE (C'liern. News, 50, 219),-In these experiments, solutions of sodium sulphite and of snl-phurous acid of various strengths were exposed to daylight and airin green glass bottles, the neck of each beiug closed by a cork throughwhich a short open tube 2 mm.wide passed, and was bent outside toexclude dust. The solutions of sodium sulphite were of strengthequivalent to 21-10, 3.77, and 0.765 parts of sulphurous anhydride to1000 of water respectively, whilst the solutions of sulphurous acid con-tained 6.00 and 1.063 parts of sulphurous anhydride in 1000 parts ofwater. During the experiments, the temperature varied frequentlybetween 50" and 90". It was found that the weaker solutions oxidisemore rapidly than the more concentrated ; that with vFeak solutionsthe sulphite is oxidised more rapidly than the sulphurous acid ; thatwith stronger solutions the smaller rate of oxidation of the sul-phurous acid was more than compensated by loss due to the diffusionof sulphurous anhydride into the air.Atomic Weight of Cerium.By H. ROBINSON (Proc. Roy. SOC.,37,150-156, and C'hem. News, 50,251-253).-The author has madeseven very careful determinations of the chlorine in a very pure pre-paration of cerium chloride ; the mean of the results obtained gives139.9035 as the atomic weight of cerium, the atomic weight ofhydrogen being taken as unity and Stas's ratios employed ; if oxygenis taken at 16, the above number becomes 140-2593. Much care andlabour was bestowed on the preparation of the cerium chloride, whichwas made from pure cerium oxalate by passing pure hydrochloricacid over it, first at a temperature of about 123", subsequently at ared heat.The purification of the oxalatc was only effected by manylaborious operations. A f u l l description of these operations and ofthe method of determining the chlorine is given in the paper.D. A. L.Action of Lead Hydroxide and Silver Oxide on AqueousSolutions of Sodium Pentasulphide and Sodium Thiosul-phate. By A. GEUTHER (Amnalen, 226, 232-240). - When anaqueous solution of sodium pentasulphide is vigorously agitated withlead hydroxide at the ordinayy temperature, lead sulphide and sodiumhydroxide are formed and sulphur liberated, according to the equa-tion : 3N&S5 + Pb,O,H, + 2H,O = 6NaOH + 12s + SPbS ; a traceof thiosulpbate is also formed.Silver oxide, under like conditions,behaves similarly to lead hydroxide, but some quantity of sulphate isalso formed, owing to the powerful oxidising action exerted by thesilver oxide on sulphur. Sodium dithionate in aqueous solution, whenagitated in the cold with silver oxide, is first decomposed according tothe equation 2S,0,Naz + Ag20 + H,O = S2O3Na2,SZO3Agz + 2NaOH,only a trace of sulphuric acid heing formed; after a time, the alka-linity of tho liquid diminishes, owing to a further reaction, in whichA. K. M.D. A. L218 ABSTRACTS OF CHEMICAL PAPERS.silver sulphide and sodium sulphate are formed. The author pointsout that these results confirm the opinion expressed by Bottger(Abstr., 1884, 342), that the pentasulphides and thiosulphates cantiotbe correctly regarded as sulphates in which oxygen has been replacedby sulphur.A. J. G.Action of Hydrogen Phosphide on Bismuth Trichloride.By A. CAVAZZT (Gazzetta, 14, 219-220) .-If a current of hydrogenphosphide is passed into a solution of bismuth trichloride in hydro-chloric acid, and water added from time to time, a black precipitate isproduced containing chlorine, phosphorus, and bismuth. I n anexperiment cihed, the quantity of hydrogen p hosphide absorbed, cor-responded with the production of a bismuth phosphide containingone atom of each element. The author considers it probable that ahydrochloride of this compound is first formed, but that this ondesiccation loses hydrogen without a t the same time losing chlorine.On frequent boiling with water, it yields metallic bismuth, and isconverted into the sulphate and nitrate of the metal by treatmentwith sulphuric and nitric acids.When heated, it ignites at a compara-tively low temperature, leaving a residue of bismiith.Action of Tellurous and Telluric Acids on Paratungstates.By D. KLEIN (Bull. Xoc. Chiin., 42, 169-170). --ellureus acid,H,TeO,, dissolves readily in solutions of sodium, ammonium, or potas-sium paratungstate, yielding in the first case micaceous crystals and adense mother-liquor. This mother-liquor gives no precipitate withhydrochloric acid in the cold, and is only decomposed after severalsuccessive evaporations to dryness with this acid. The mother-liquorcontains tellurous acid, which is only precipitated by siilphurous acidor hydrogen sodium sulphite in the cold, after addition of hydro-chloric acid.The action of tellurous acid on ammonium or potassium para-tnigstate yields no crystalline products, but only a pulverulentdeposit, which contains tungstic and tellurous acids, and behares likea tungstotellurite.When telluric acid, HaTeOd, acts on potassium paratungstnte, acrystalline compound is formed which contains tungstic and telluricacids and potassium.It is evident that the behaviour of the acids of t,ellurinm towardsthe alkaline tungstates is very different fiom that of the acids ofs ul p hu 1’.V. H. V.C. H. B