148 ABSTRACTS OF CHEMICAL PAPERS. I n o r g a n i c Chemistry. Critical Temperature and Pressure of Liquid Oxygen. By S. WRORLEWSKI (Compt. rend., 97, 309-310).-When oxygen is liquefied by pressure in a bent tnbe surroutided by liquid ethylene which is caused to evaporate rapidly, it is found that, as the amount of liquefied oxygen increases so that it rises above the surface of the ethylene, the pressure necessary to continue liquefaction gradually increases, and when the liquid oxygen rises t o a certain height in the tube, the meniscus becomes indistinct and finally disappears. These results are due to the fact that the temperature of that part of the tube above the liquid ethylene gradually increases as the distance from the ethylene increases. The disappearance of the meniscus takes place at a, pressure of about 50 atmos., and on slightly reducing the pressure the meniscus reappears.Carbonic anhydride was liquefied by pressure in a tube, the lower part of which was placed in melting ice, whilst the upper part was heated to 50°, the intermediate portions being of course at inter- mediate temperatures. As the liquefied gas approached the heated portion of the tube, the pressure required to continue liquefaction gradually increased until at about 76 atmoa. the meniscus disap- peared, but it reappeared on slightly reducing the pressure and con- sequently reducing the volume of the liquid. The disappearance and reappearance of the meniscus in both cases evidently takes place at that part of the tube which is at the critical temperature for the particular gas, and the pressure observed at the time of disappearance is the critical pressure.The critical pressure for oxygen is about 50 atmos., and the critical temperature is approximately - 113". C. H. B.INORGANIC CHEMISTRY. 149 Critical Point of Oxygen. By E. SARRAU (Compt. rend., 97, G9-490) .-The critical pressure and temperature calculated by means of Clausius’ formula from the results of Amagat’s experiments on the compressibility of oxygen, are 48.7 atmos., and - 105.4” respectively. These values agree fairly well with Wroblewski’s determinations (see preceding Abstract). Conduct of Moist Phosphorus and Air towards Carbonic Oxide. By I. REMSEN and E. H. KEISER (Chenz. News, 48, 199- 201).-In reference to the work of Hoppe-Seyler (dbstr., 1880, 3), Baumann (ibid., 1882,691), Traube (ibid., 1882, 795), and Leeds (ihid., 1880, 237), on the existence of an active form of oxygen distinct from ozone, the authors have repeated some of the experiments.A repeti- tion of Traube’s experiment led the authors t o confirm his statement, viz., that the oxidation of palladium-hydrogen is due to bhe formation of hydrogen dioxide. And again, several repetitions of Leeds’s and Baumann’s experiments, in which great care was taken to prevent the mixed gases from inside the apparatus coming in contact with organic matter, led the authors to negative Leeds’s and Baumann’s conclu- sions; under these conditions no oxidation of carbon monoxide to dioxide took place. In these experiments ad1 the stoppers were covered with water or mercury, connections were made with pieces of glass tubing bent twice a t right angles, so as 00 avoid india-rubber joints, and all necessary plugs were of asbestos.I n some experiments, the asbestos plugs were replaced by cotton-wooll with the result that the gas which previously contained no carbonic anhydride, now precipitated baryta-water ; this explains Leeds’s error. No satisfactory explanation is given of the negative results obtained by Leeds and Baumann when no carbonic oxide was used. The ant,hors are of opinion that the action of air and moist phosphorus on carbonic oxide furnishes no evidence of the existence of the so-called active oxygen. C. H. B. D. A. L. Atomic Refraction of Sulphur. By R. NASINI (Gazzetta, 13, 2 9 6 4 1 1 ) .-Bruhl’s labours on atomic refraction have shown that the same element may have different.atomic refractions according to its mode of union with the other elements, but up to the present time the atomic refraction of sulphur in its various compounds has not been made the object of special study. After noticing what bas been already done i n determining the refractive indices of various sulphur compounds, the author points out that the questions he proposes to solve are: 1. To ascertain the value of the atomic refraction of sulphur cor- responding with oxygen, where bivalent sulphur is united with two univalent groups, as i n the mercaptans. 2. Its atomic refraction where the two valencies of sulphur are satisfied by the same carbon-atom. 3. To ascertain whether a variation in valency has any influence on its atomic refraction, by a study of inorganic sulphides and deri- vatives of carbon acids in which the sulphur is quadrivalent or sexavalen t.150 ABSTRACTS OF CHEMICAL PAPERS.?a. ---- 5 ' 0 1.3 2.8 3.4 9.8 2 - 4 The experiments were all made with liquids: these for the most part were supplied by Kahlbaum, but were purified before the deker- minations were made. The author employed the empirical formula n-1 used by Landolt and Bruhl, as being but little affected by varia- tions of temperature. H. A. Lorentz and L. Lorenz have recently shown (Wied. Ann., 9, 64, and 11, 70) that the formula 7 is the correct expression for the refractive power of a substance ; it gives excellent results, and has also been used bg the author.The values for this formula, calculated by Landolt from Bruhl's nume- rous experiments, are given in the subjoined table, where ra and rA represent the atomic refmctions of the elements with respect to the line a of the hydrogen spectrum, and with respect to the con- n--1. stant A of Cauchy's formula as functions of the old formula - d ' and T ' ~ and r'* the same values for the new formula. 9?? - 1 n + 2 d r A . 4.86 1-29 2-71 3.29 9-53 2'00 Carbon c .................. Hydrogen H .................. Chlorine c1. ................. Increment for each double bond.. ........ Oxygen (alcoholic) 0' ................ .. (aldehydic) 0" ................ 2-48 1.04 1.58 2.34 6-02 1*78 ?i-1 d ' ~ 2'43 1.02 1-56 2-29 5.89 1.59 n2-1 (a: + 2)d' The determinations of the refractive index were nearly all made at 20" with a spectrometer of Bartels and Diedcrichs, by the method of minimum deviation, using the lines a, p, and y of the hydrogen spectrum and the D sodium line. The sp.gr. of the substance was determined at 20°, referred to water at 4", reducing it t o a vacuum by means of the formula dt4 = - (2-1) +A, where rn is the weight of the substance at a temperature t, w that of the water at the same ternpe- rature, and X the mean density of the atmosphere. The substances examined were ethyl mercaptan, EtHS ; ethyl sul- phide, Et,S ; ethyl bisulphide, EtS, ; isobutyl mercaptan, C4H,.SH ; ethyl monothiocarbonate, OC(OEt)(SEt) ; isopentyl mercaptan, C,H,,.SH ; isopentyl sulphide, ( C5HI,),S ; diethyl dithiocarbonate, OC( SEt), ; carbon bisulphide, CS, ; the compound, CS( OEt), ; sul- phurous anhydride, SO, ; and sulphuric acid, H2SOa.The results are given in three tables, and from an inspection of them it appears that the atomic refraction of sulphur, like that of oxygen, has two values, according as the two vdencies are satisfied by two differeut univalent rn WINORGANIC CHEMISTRY. 151 Sulphur with two single bonds . . . . . . . . . . ,, ,, a double bond . . . . .. .. .. . . groups, as in mercaptian, &c., or by the same carbon-atom as in carbon bisulphide. These two values are as follows :- ra . VA. r', . r'A. -- -- --- 14 -10 13 -53 7 *87 7-65 15-61 15-09 9.02 8-04 n2- 1 (.Z + 2)d' I n the case o€ the oxygenated compounds of sulphur, it would seem that the atomic refraction has only one value, although it differs considerably from those given above.It is now established that the atomic refraction of an element may var-y, not only as it is more or less closely united with other elements -that is, by single or double bonds-but also that the nature of the atoms or variation in the capacity of saturation of the element may greatly influence the value of the refraction-constant. Comparative researches on other mnltivalent elements, such as phosphorus and arsenic, will no doubt throw light on this most important question. C. E. G. Basic Sulphates. By 5. HABERMANN (Monatsh. Chem., 4, 78i).- Preliminary Notice.-The basic copper sulphate, 6Cu0,2S03,5H,0, which Reindel obtained as a blue-green precipitate on adding ammo- nia in sufficient quantity to a boiling solutioii of normal cupric sul- phate (Gmelin-Kraut, 6 Aufl., vol.iii, p. 628), is also formed by boiling a solution of the normal sulphate (Pickering, C. J., 1883, Abstr., 853), and the author of the present notice has obtained it by treating the solution of the normal sulphate with ammonia or with sodium carbonake in certain proportions. Basic sulphates of nickel, cobalt, zinc, and cadmium are formed in like manner with either of these precipitants, but the salts thus ob- tained are not analogous in composition to the copper salt. Further details are promised. H. W. Action of Potassium Permanganate on certain Sulphur- compounds. By 11. HONIG and E. ZATZEK (nlonatsh. Chem., 4, 738 -'752).-In this paper the authors describe a large number of expe- riments on the action of potassium permanganate on the thiosulphates, sulphites, and sulphides of the alkali-metals, the results of which may be summarised as follows :- 1.The thiosulphates of the alkali-metals are completely oxidised by the permanganate at ordinary temperatures, only in alkaline solu- tion. Whatever may be the concentration of the permanganate solution, the complete oxidation of 1 part sodium thiosulphate (Na$3,0,,5H20) requires 1.6366 part potassium permangsnate. The152 ABSTRACTS OF CHEMICAL PAPERS. composition of the resulting precipitate is best represented by the for mu1 a KH,Mn,O,. 2. The s u l p h i t e s of the alkali-metsls are completely oxidised at ordinary temperatures both in neutral and in alkaline solution. The quantity of permanganate required for oxidation of I part by weight of sodium sulphite (Na,S03) depends on the concentration of the permangsnate solution, being less in proportion as that solution is more dilute, The composition of the resulting manganese precipitate is variable, m d likewise depends on the concentration of the per- manganate solution.3. The action of permanganate at ordinary temperatures on the mono- a,nd poly-sulphides of the alkali-metals gives rise to sul- phuric acid, trithionic acid, and free sulphur ; at the boiling heat all or nearly all the sulphur is oxidised to sulphuric acid. Direct Union of Nitrogen and Hydrogen. By H. B. BAKER (Chem. News, 48, 187--188).-This communication is a reply to Johnson (Trans., 1881, 128,130). The author describes various expe- riments with Johnson's and other apparatus, and ultimately comes to the conclusion that nitrogen prepared from air, either by the removal of the oxygen by cold phosphorus, or by patassium pyrogallate, or by hydrogen in the presence of warmed platinum sponge, does not com- bine directly with hydrogen to form ammonia.When, however, the hydrogen was passed through a solution of silver nitrate, and subse- quently through three bottles containing a saturated solution of ferrous sulphate, the author always obtained a brown coloration in the second Nessler tube. Note.-Johnson has discontinued the use of silver nitrate for the pur$catiort of his hydrogen (Chem. News, 48,202). H. W. D. A. L. Nitrogen Iodides. By A. GUYARD (Compt. rend., 97, 526-531). -Nitrogen iodide in contact with water or aqueous ammonia is as sensitive to luminous vibrations as to calorific, sonorous, or material vibrations.When exposed to light, the iodide is rapidly decomposed with effervescence and gives off pure nitrogen, ammonium iodide and a small quantity of ammonium iodate being also formed. I n presence of water, the decomposition usually terminates in a violent explosion, but in presence of ammonia it proceeds quietly to the end. Nitroqen iodide is as sensitive to diffused light as to direct rays, the rapidity of decomposition being proportional to the intensity of the light. The decomposition takes place equally well a t lo, 5", lo", or the ordinary temperature. The infra-red spectrum has no influence on the decom- position, but the visible spectrum acts powerfully, the maximum effect being produced by the yellow rays and the minimum by the violet.Nitrogen iodide of the composition NH, is decomposed by light in presence of water, without explosion, in accordance with the equation 2NBJ = NHJ, + N. Nitrogen iodide, however, rarely has this composition, and usually contains a greater or lesser proportion of other iodides. The compound therefore generally decomposes a t first in accordance with the above equation, but explodes when the iodide,INORGANIC CHEMISTRY. 153 NH31, begins to decompose. The decomposition of the typical iodide, NH12, in presence of ammonia, takes place in accordance with the equation 5NH1, + = lONHII + 7N. One and the same nitrogen iudide will give off more nitrogen in presence of ammonia than in presence of water; in the first case ammonium iodide is formed, in the second the diiodide.The decomposition of nitrogen iodide in ammonia may be used photometrically to determine the chemical and mechanical equivalent of light. The apparatus employed consists of a small flask with a long neck graduated in cubic centimeters, and provided with a stopper. The neck also carries a side tube similar to that of a Gay- Lussac burette. 1.27 gram of iodine is placed in the flask, which is then completely filled with ammonia of 22", carefully stoppered, with exclusion of air babbles, and exposed to light. 1.27 gram of iodine gives off 33.5 C.C. of nitrogen. The final reaction is the same whether nitrogen iodide or a mixture of iodine and ammonia is employed, and whether the mixture of iodine and ammonia is exposed t o light at once, or time is given for the formation of nitrogen iodide.The decomposition takes place in accordance with the equation 13NH3 + 101 = 10NHIL + 3N. Preparation of Ammonium Iodide and Iodwte.-When a mixture of iodine with excess of ammonia is exposed to light, nitrogen is given off, the free iodine entirely disappears, and ammonium iodide and iodate are formed. The ammonia is driven off and the liquid con- centrated, when the ammonium iodide cryddlises out, and the iodate remains in solution.. When iodine is mixed with aqueous ammonia, part of the iodine forms ammonium iodide, and the remainder is converted into nitrogen iodide. Afterwards, in presence 0% light and an excess of ammonia, more ammonium iodide is formed and nitrogen is given off.The first part of the change is chemical, the second photochemical. The principal reaction is represented by Odling'sequation 3NH3 -t 21, = 2NHJ + NH12. When the iodine is in excess, ammonium diiodide is formed, and the nitrogen iodide produced has approximately the composition NHJ ; with proper proportions of iodine and ammonia, the nitrogen iodide has approximately the composition NHI, ; with an excess of ammonia, a greater proportion of ammonium iodate is formed. Nitrogen iodide of the composition NHI, is but slightly affected by washing with pure water. Ammonia added to ammonium diiodide forms nitrogen iodide with the second atom of iodine. Under ordinary conditions, z(NH,O) + 233(NH40) + I,, = NH,O,I& + 154NHdI + 10(N8Hg115) + 227H0 + x(NH40),* where aNHIO represents the excess of ammonia which must always be used, is the simplest equation which expresses the observed facts.The formula N,HgIl5 is approxima'tely 8NHIz. With twice the excess of ammonia, about twice the amount of ammonium iodate is formed, and the nitrogen iodide consists mainly of N,H,15, or approximately 3NH I,. The formulae given by previous investigators are probably correct, b u t refer to bodies prepared under different conditions. * This equation is given exactly as it is in the original, it is, however, incorrect, aa the two sides are N233,H932,1303,(328 = N:36,H93pT305,0Q39. YOL. XLVI. m154 ABSTRACTS OF CIIEMICAL PAPERS. Nitrogen iodides are decomposed even by very dilute sulphuric, hydrochloric, or sulphurous acid, a t first with effervescence, but afterwards with violent explosion.They dissolve in sodium thiosul- phate, with formation of sodium iodide, ammonium snlphate, and free ammonia. The free ammonia is that existing in the nitrogen iodide ; the ammonium in the ammonium sulphate is derived from the nitrogen existing in the nitrogen iodide in the form of triiodamine. Nitrogen iodide is partially decomposed by potassium iodide in the dark, with formation of potassium diiodide free from ammonia, and a nitrogen iodide insoluble in the alkaline iodide, that is, the iodide NHI, loses an equivalent, or part of an equivalent, of iodine, and yields a new iodide. When exposed t o light, however, the nitrogen iodide is completely decomposed by the potassinm iodide, and the liquid con- tains ammonium iodide.Potassium cyanide dissolves nitrogen iodide even in the dark, with evolution of nitrogen. Nitrogen Copper Iodide.-When an ammoniacal solution of a copper salt is mixed with potassium diiodide, a brilliant, crystalline, garnetL coloured precipitate of the composition Cu12,2NH21 is gradually deposited. When dried, this compound is very stable, but it is entirely decomposed by water, with formation of ammonium diiodide, and a bronze-coloured cupric oxyiodide, CuOJ, which is decomposed by heat into black cupric oxide, iodine, and oxygen. The double copper nitrogen iodide is decomposed by aqueous ammonia, with for- mation of an ammoniacal solution of cupric iodide and a residue of an explosive nitrogen iodide free from copper.When the double iodide is heated, iodine and the products of the decomposition of nitrogen iodide are given off, and a residue of perfectly pure cuprous iodide is left. When distilled, the double iodide yields cuprous iodide, and brown, violet, and ammoniacal vapours. The brown vapours condense to a black product, decomposed by water witoh formation of a black crystalline nitrogen iodide, which resembles iodine in appearance, but which differs from all the other nitrogen iodides by dissolving with effervescence in a solution of potash or soda, nitrogen or hydrogen being given off, and a, considerable quan- tity of ammonia formed. When Schweitzer’s reagent, prepared by Peligot’s method, is mixed with potassium diiodide, a crystalline black double iodide of nitrogen and copper is formed, which resembles the preceding compound in its general properties, but yields an explosive cupreous residue when decomposed by washing with water.By I. REMSEN and E. H. REISER (Chem. News, 48, 201--202).-1n course of the experiments alluded to in this vol, p. 149, the authors had a suspicion that the phosphorus with which they were working might have contained some carbon- aceous matter. To remove this the phosphorus was distilled in an atmosphere of purified hpdrogen, and the vapour condensed in cold water. The distilled phosphorus presented a peculiar appearance ; it floated on the surface of the water, forming a snow-white layer, and when placed in warm water changed into ordinary phosphorus.After many experiments the authors found that this variety of phosphorus C. H. B. White Phosphorus.INORGANIC CHEMISTRY. 155 could be prepared in the following manner : Sticks of phosphorus are placed in a tuhulated retort, the neck of which is inclined upwards, and projects into a double-necked globular receiver, containing a layer of water and ice 18 in. deep in the deepest part. The receiver is supported in a vessel of cold water, and the bent tube, which passes from the other neck of the receiver, dips into cold water. A glass tube is fitted into the tubulure of the retort to supply purified hydro- gen, which is passed until the apparatus is filled with i t ; the current is then stopped, and the distillation proceeded with ; this is conducted steadily so that the vapour as it issues from the retort does not con- dense to a liquid.In successful operations a thin white cake is found floating on the water. The apparatus is allowed to cool, the retort disconnected, and the receiver with its contents put under water to displace the hydrogen and remove the phosphorus ; if this precaution is not taken, the phosphorus is liable to take fire, and give rise to an explosion of the mixture of hydrogen and air. White phosphorus is light and plastic ; if it is placed on bibulous paper as it dries, it fumes, melts without taking fire, and changes to ordinary phosphorus, with which its melting point is identical. It iR soluble in carbon bisulphide, and is not affected by sunlight so readily us ordinary phosphorus ; a sample after a year became slightly yellow, but was otherwise unchanged.I). A. L. By A. GAVAZZI (Gazzetta, 13, 324-325) .-0 n passing gaseous hydrogen phosphide through a neutral aqueous solution of platinic chloride, an ochreous yellow precipitate of the composition PtPHz is obtained: this is insoluble in water and hydrochloric acid. It ignites when heated to 100-llO", or when moistened with fuming nitric acid. Arsenic phosphide, ASP, is formed by the action of hydrogen phos- phide on a solution of arsenious anhydride in hydrochloric acid. An aqueous solution of potassium permanganate absorbs hydrogen phosphide at a low temperature, the reaction being represented by equations- Reactions of Gaseous Hydrogen Phosphide. PH, + 2RMnQa = KzHPOs + 2MnOz + HzO PH, + 2KMnOd = KzHPOd + Mnz03 + H20.C. E. G. Preparation of Phosphorus Oxychloride. By E. DERVIN (Compt. rend., 97, 576--578).-When phosphorus trichloride is mixed with potassium chlorate a violent reaction takes place, phosphorus oxychloride and potassium chloride being formed in accordance with the equation KC10, + 3PC1, = 3Pocl3 + KC1. This reaction may be utilised for the preparation of phosphorus oxychloride. 500 gram8 of pure phosphorus trichloride free from uncombiried phoPphorus are placed in a retort of 750-1000 C.C. capacity, connected with an inverted condenser, and 160 p m s of finely powdered potassium ohlorate is added through the tubulure i n quantities of about 4 grams st a time, care being taken to wa.t each time uirtil ebullition ceases before adding more chlorate.When the whole of the chlorate has been added, the liquid is distilled. The yield is very satisfactory, and the oxychloride contains but mere traces of chlorine. C. H. B. m 2156 ABSTRACTS OF CHEMICAL PAPERS. Action of Sunlight on Phosphorous Anhydride. By A. IRVING (Chem. News, 48, 173).-The author prepared his phosphorous anhydride by passing a slow current of dry air over molten phos- phorus, and found that the product turned brown, and changed into free phosphorus and phosphoric anhydride when exposed in sealed tubes to direct sunlight (compare Lewes, Trans., 1884, 10). D. A. L. Boron. By A. JOLY (Cornpt. rend., 97, 456-458).-The products of the reduction of boric anhydride by aliirninium are : (1.) The boride, BAl, which forms golden-yellow hexagonal lamellze, described by Deville and Wohler.(2.) The boride, B6A1, which forms large black la,mells, analysed by Hampe (Annnlen, 183, p. 75). (3.) Yellow quadratic crystals of adamantine lustre containing carbon and alu- minium. (4.) A boron carbide, or more probably several carbides formed by the alteration of the preceding compounds, at a high tem- perature, in presence of carbon and excess of boric anhydride. This carbide forms small black very hard crystals, with a bright metallic lustre, insoluble in boiling nitric acid. They have a sp. gr. of 2.542 a t 17", and contain 15.7 per cent. of carbon, corresponding with the formula B,C. C. H. B. New Silver Compounds. By T. POLECK and K. TH~~MMEL (Ber., 16, 2435-2448) .-Gutzeit has shown (Plznrm. Zeit., 1879, 263) that when gases containing arseniuretted hydrogen impinge on a piece of filter-paper moistened in its centre with one drop of a concentrated solution of silver nitrate, the wet spot assumes a lemo~-yellow colonr, whilst a t the periphery a brownish-black ring forms, which slowly broadens towards the centre until the whole spot becomes black.If the spot, whilst still yellow, is moistened with water, it blackens over the whole surface, and a t the same time shows a strongly acid reaction. Hydrogen sulphide, phosphide, and antimonide give similar results. The present paper details experiments on the chemical nature of these reactions. Hydrogen sulphide is passed into a concentrated solution of silver nitrate (1 part AgNO, in 0.7-1.0 part, water) kept constantly agitated, when a yellowish-green precipitate of the formula Ag2S,AgNOa is ob- tained.The supernatant liquid has a strongly acid reaction, does not contain sulphuric acid, and yields a considerable quantity of ammonia when distilled with potash. The precipitate can be heated to 180" without decomposition, and then forms a dark-green powder. It is decomposed into silver nitrate and silver sulphide by treatment with water or alcohol. On oxidation with nitric acid of sp. gr. 1.18 an orange-red coloured powder is frequently obtained. This compound is also obtained by the action of sulphur on a boiling concentrated solution of silver nitrate, and after purification gave results corre- sponding with the foraiula Ag,S, Ag,S04. It dissolves in boiling nitric acid, is decomposed by boiling water into silver sulphide and sulphate, and by cold hydrochloric acid into silver sulphide and chloride.Arsenic trihydride acting on dilute solution of silver nitrate has long been known t o yield metallic silver, arsenious anhydride, andINORGANIC CHEMISTRY. 157 nitric acid; with a concentrated solution, however, the reaction is very different. The first few bubbles of gas produce a deep lemon- yellow coloiation, no precipitate is formed, and the liquid acquires an acid reaction; this colomtion remains for one or two devs, then the liquid becomes colourless, silver is precipitated, and the solution contains arsenious m d arsenic acids. If a r,ipid stream of arsenic trihydride be passed into a concentrated solution of silver nitrate a t O", the whole liquid solidifies to a yellow crjstalline mass, but rapidly blackens from separation of silver.Many experiments were tried to isolate tbe compound, but its instability was too great. Analysis by an indirect method pointed to the formula With Concentrated solutions of silver nitrate, hydrogen phospbide gave results exactly similar in appearance to those obtained with arsenic trih ydride. The composition of the yellow precipitate from indirect determinations was Ag3P,3 A gN 0,. d ello ow precipitate is also obtained by the action of antimony hri- hydride on concentrated solution .of silver nitrite. It could not be isolated, but indirect determinations gave the formula Ag,Sb,3AgN03. Unlike arsenic, phosphorus, and sulphur, metallic antimony does not yield the double compound ; when it is placed in a solution of silver nitrate, A@b is first formed, but is soon converted into antimonious oxide and silver. A.J. G. Ag3 AS. 3 AgN03. Silver Nitrite and Ammonia. By A. REYCBLER (Bey., 16, 2425-2428) .-On dissolving silver nitrite in concentrated aqueous ammonia heat is evolved, aud the liquid soon deposits well-formed brilliant yellow prisms of the formula AgNO,,NH,, soluble in water, sparingly soluble in alcohol, nearly insoluble in ether, and melt.ing at 70". Long-continued heating above the melting point decomposes the compound, all the ammonia being expelled, and the residue con- sisting mainly of silver nitrite. On gently heating the compound with ethyl iodide, it yields silver iodide, ethyl nitrite, and ammonia. On heating the nionammonia compound with alcoholic ammonia and precipitating with ether, the diammonia compound SgNO,[NH,), is obtained as a white crystalline mass, rapidly losing ammonia on exposure to air.The finely powdered monammonia compound rapidly absorbs ammonia gas, with considerable evolution of gas, and apparently yields a triammonia compound, AgN02(NH3), ; it, is readily soluble in water, and rapidly loses ammonia on exposure to the ah. Crystallised Calcium Silicophosphate produced in the Dephosphorisation of Iron. By A. CARNOT and RICHARD (Compt qserid., 97, 316--320).-The slag formed in working the Thomas- Gilchrist process at Joeuf (Meurthe-et-Moselle) has a brownish 01. blackish colonr, and is more or less crystalline, some parts consisting of transparent crystalline matter, which acts strongly on polarised light, whilst other parts have a reddish colour, and resemble brown Immatite.The surface of the slag is covered with black crystals, some of which are slender needles, whilst others are right' rhombic A. J. a.158 ABSTRACTS OF CHEMICAL PAPERS. prisms with brilliant faces. These crystals are frequently aggregated in columnar masses, which terminate i n small vitreous perfectly translucid blue crystals. Similar blue crystals are found in the cavities in the slag, and appear to form one of its principal con- stituents. These are very constant in composition, but frequently enclose small black needles or particles, which can, however, be removed by means of a magnet. The blue crystals have h e com- position- Pz05 SiO,.Al2O3. CaO. MgO. FeO. MnO. 29.65 16-42 2.76 53.20 traces 1.80 traces = 99.83. Vanadium could not be detectred. The numbers correspond with the formula 8P,0,,8SiOa,A1,0,,Fe0,36Ca0. Regarding the crystals as consisting essentially of calcium silicophosphate, the formula becomes P,05,Si02,5Ca0 or Ca,P20B + C%,SiO,. The composition of the crystalline slag is variable ; it contains a lower proportion of phos- phoric acid than the blue crystals, and a considerable excess of ferrous and manganese oxides. The calcium silico-phosphate crystals belong to the rhombic system, the angles being riam = 113” 10’ and e’e’ (on p ) = 64’. They are strongly doubly refractive, and exhibit well-marked dichroism. When the plane of their optical axis is parallel with the principal section of the Nicol’s prism, they have a cobalt-blue colour; when i t is perpen- dicular, they are almost colourless.C . H. B. Presence of Yttrium in the Sphene of Biellese Syenite. 13;. COSSA (Gazzetla, 13, 326)’.-The author has found yttrium arid cerium in the sphene of Biellese syenite to the amount of about 2.3 per cent. This is an important fact, as it affords additional evidence of the analogy between the syeiiite of Biellese and those of Planceuschen- giund and Sweden. Besides showing that substances exist in the Alps which were formerly believed to be exclusively confined to Northern Europe, it proves that these rare metals are widely diffused, and their association with calcium compounds may be important in relation to their valency.C. E. G. Separation of Gallium. By L. DE BOWBAUDRAN (Compt. rend., 97, 295-297, and 521--522).-From Vanadium-(I.) The feebly acid hydrochloric acid solution is mixed with arsenious acid and an excess of acid ammonium acetate, and treated with hydrogen sulphide. Vanadium is not precipitated, but the arsenious sulphide carries down the whole of the gallium. The precipitate is washed with water con- taining ammonium acetate and hydrogen sulphide, and treated with aqua regia. The arsenic acid is reduced with sulphurous acid, and a current of hydrogen sulphide is passed through the strongly acid liquid, when the arsenic is precipitated alone, all the gallium remain- ing in solulion. This is the only process which gives accurate results when used alone, and it is especially useful fur separating small q-ntities of gallium from large quantities of vanadium.(2.) TheINORGANIC CHEMISTRY. 159 solution is almost neutralised with ammonia, mixed gradually with an excess of ammonium sulphide, and agitated. Dilute hydrochloric acid is then added in considerable excess with constant agitation, and the precipitated vanadyl sulphide is filtered off and washed with dilute hydrochloric acid containing hydrogen sulphide. The filtrate is boiled with aqua regia to destroy ammonium salts, the nitric acid is then expelled, and precipitation repeated six or seven times. The vafiadyl sulphide is also dissolved in aqua regia, and reprecipitated several times. (3.) The hydrochloric acid solution is made alkaline with ammonia, and boiled until the liquid is neutral.The precipitate is redissolved and reprecipitated two or three times ; the filtrake is treated by method (1) in order to separate the last traces of gallium. (4.) The solution is mixed with sulphuric acid and ammonium sul- phate in proper proportions, and the gallium alum is purified by recrystallisation. If the amount of gallium is very small, process (1) is used ; if the proportion of gallium is large, and that of vanadium small, the greater part of the gallium is removed in the form of alum, and the mother- liquid is treated by the following method. When the gallium and vanadium are present in approximately equal proportions, khe liquid is twice boiled with ammonia (2), and the filtrate treated by (1). The precipitated gallium hydroxide is converted into alum, and the mother-liquor is again boiled with ammonia.The filtrate is treated by (1) : the precipitate is mainly converted into gallium alum, and the mother-liquor is finally treated by (1). From Tungsten.-The tungsten is converted into alkaline tnngstate, and the solution evaporated almost to dryness at a gentle heat in pre- sence of a considerable excess of hydrochloric acid, a small quantity of water is then added, and the liquid again evaporated almost to dryness. The residue is treated with a moderately large quantity of very dilute hydrochloric acid, gently heated, and the liquid filtered. The filtrate is free from tungsten; the traces of gallium in the precipitate are removed by dissolving it in ammonia, and repeating the process. From Phosphoric Acid.-(1.) The gallium is precipitated by potas- sium ferrocyanide in presence of a large quantity of hydrochloric acid, and the precipitate is washed with water strongly acidified with hydrochloric acid. (2.) The solution is mixed with about one-third its volume of strong nitric acid, and the phosphoric acid precipitated by meam of ammonium molybdate, the gallium and molybdenum being afterwards separated by the method previously described. (3.) The feebly acid solution is mixed with arsenious acid and ammonium acetate, and treated with hydrogen sulphide, as described above.C. H. B. The solution contains small quantities of gallium. Diffusion of Vanadium in the Mineral and Vegetable King- doms. By L. RICCIARDI (Gazzetta, 13,259-262).-After a recapitu- lation of the results obtained by various authors on the occurrence of vanadium in rocks and minerals, the author gives the results of his own experiments on the existence of that metal in volcanic emana- tions ancient and modern.These are as follows, the numbers denot-160 ABSTRACTS O F CHEMICAL PAPERS. i n g the percentage of vanadium sesquioxide found in the several substances examined :- Lava of Vesuvius (1 868) ........ Y , ,, (1871) ......... 7 , ,, (1872) . . . . . . . Ashes from Vesuvius (18i.2) .... Lava of Vesuvius (1851) ........ Lava of Etna (1669) ............ 7 9 ,, (18’79) ............ Basalt of Pachino .............. Basalt of the Isola dei Ciclopi.. ..... 0.0063 per cent. 0.0075 ,, 0.013 ,, 0.105 ,, 0.0081 ), ~0.0102 , 7 0.0034 ), 0.006 ,, 0.0084 ,, Scacchi has found vanadium in incrustations of the Vesuvian lava of 1631.E. Rechi (Atti della It. Accademia dei Lincei [3], 3,403 [1878-79]), after having found this element in argillaceous limestones, in schists and in sands, has established its presence in plante, especially i n those growing on clay soils. The author of the present paper bas also found it in the ashes of grasses growing on the Etna lava of 1660, b u t the proportion was too small for qnantitative estimation. Its occnrrence in plants may be regarded as having some relation to the isomorphism of vanadic and phosphoric acids. H. W. Sulphur Compounds of Molybdenum. By G. KRGS (Ber., 16, 2044--2051).-According to Berzelius, molybdenum forms not only R di- and tri- but also a tetra-Pulphide, MoS,, a compound which would point to molybdenum as possessing a quanticalence of eight, and would be analogous to the uranium tetroxide.The author has sue- ceeded in isolating this tetrasulphide by melting molybdic acid with potassium carbonate, exhausting the melt with water, and passing hydrogen sulphide into the solution when heated to the boiling point. A black powder together with a crystalline substance separates out. This mixed material is washed first with cold water, then with hot water to dissolve out the molybdennm di- and tri-sulphide, and the resultant chocolate-brown powder is heated in a current of hydrogen sulphide until its weight is constant. The result of the analysis show that this substaiice is molybdenum tetraadphide. The author also describes a series of compounds intermediate between the salts of molybdic and sulphomolybdic acids, which may be designated by the generic term oxythirmolybdates. Ammonium o r t l ~ o x ~ t h i o i ~ ~ ~ l y b d ~ r t e , prepared by passing hydrogen sulphide into an ammoniacal solution of ammonium moly bdate, crys- tallises in golden-Fellow needles of the composition (NH&Mo02S,, which was assigned to the substance by Debray.The corresponding potassium salt, forms reddish- golden needles. Besides the crystalline orthoxythiomolybdnte, a number of amor- phous oxysnlphomolybdates are obtained by the decomposition of the molybdates by the alkaline hydrosulphide. Ammonium pyroxy- thiomolybdate, prepared by decomposing ammonium moly bdate with ammonium hydrosulphide, is a reddish-golden precipitate having tht!INORGANIC CHEMISTRY.161 composition H,Mo,O,S, (= 2H2Mo0,S2 - H2S), which evidently stands to orthoxymolybdate in the same relation as ortho- t o pyro-phos- phoric acid. The corresponding sodium salt is a golden amorphous powder. Thiomollybdates. - These compounds were obtained by Berzelius by passing hydrogen sulphide into the tnolybdates and evaporating the liquid; the substances formed by t,he process are, however, far froin pure, owing to a loss of hydrogen sulphide and formation of the oxythiomolybdates. The potassium salt c m best be prepared by fusing together potassinm carbonate, sulphur, aiid a large excess of the natural molybdenum sulphide. Bit hio )n o 2y bclat es.-On passi rig hydrogen sul phid e into a solution of potassium molybdate containing a large excess of free alkali, an orange-yellow precipitahe separates out ; this has the composition KGMo2S9, or potassium dithionwly bdute.V. H. V. Complex Inorganic Acids. By W. GIBBS (Chew. News, 48, 155) .--Two communications from ,the author on this subject have already appeared in this Jonrnal (Abstr., 1882, 469, i O 2 ) . In these communications only binary compounds have been referred to, and these can be represented by the general formula:- mR~03.nR’205.~RJ‘z0, in which m = any even number from 10 to 48 ; R = either molybde- num or tungsten ; R’ either phosphorus or arsenic ; and R” the basic radical. He has now extended the genesalisation, and states that the phosphorus and arsenic may be replaced by vanadium or antimony, or possibly by niobium acd tantalum ; for example, well-defined and beautifully crystalline vanadio-moly bdates have been obtained haring the formulae :- ~ M o O , , V , ~ ~ , ~ A ~ ~ O , H ~ C ) + 4Aq.16Mo03,V20,,5Ba0,H~0 + 28Aq. Moreover, ihe group R’?05 may be replaced by the group R,O, as As,O,,Sh 0 Thus the formula of an ammo- nium phosphoroso-molybdate is - O,, and probably V,O,. 243100, 2PzO3,5Am20 + 20Aq. These R,03 compounds are converted by oxidation into the salts con- taining the group R205. Klein has described salts containing R,03 ; salts of this class containing hypophosphorous acid have also been obtained, such as the ammonium hypophosphomolybdate of the formula 24Mo03,6P02,6Am20 + 7Aq. There are a great many ternary compounds of a similar character containing moljbdic or tungstic oxide united with two other oxities.A great many have the general formula, mR03ri,R’205,~~R’205rrRJ’?0, in which RO, = molybdic or tungstic oxide, whilht R’2@5 and R”O5 = two different oxides of the same type ; for example, P2O5 and V,O,. It has not as Jet been proved that any two known oxides of the type R205 can enter together into such compounds. The following are some examples of these salts :-162 ABSTRACTS OF CHEMICAL PAPERS. 14M003,8Vz05,Pz0,,8Amz0 + 50Aq. 48MoO3,V205,2PzO6,7Arn20 + 30Aq. 60W03,Vz05,SPz05,10Am20 + 60Aq. But the compounds containing Moo3 or WO, in combination with oxides of two types are still more numerous. They have the follow- ing general formulae :- 16~03,3V205,P20,,5A~lzO + 37Aq.rnR03,nR’~051pR”z03,rR”‘z0 ; mR03,nR’2U5pR20;~,rR’‘’z0 ; in which Rz05 may be Pz06, V205, As,05, Sbz05, and probably NbZ05 and T%05, whilst RzOs may be B303, P203, V&, Asz03 Sbz03. The author has also prepared salts belonging to the ternary compounds with the general formula mR03,nRz05,pR”Oz,rR”’02. None of this series containing R‘*03 in place of R20a have as yet been prepared. Quarternary compounds also exist, for the author has obtained the following in well-defined crystals :-GO WO3,3P2O~,V2Q~,V0~,18€3a,Q + 150H,O, which is reducible to the general formula :- mR03,nR”~05,~R’zOa,rR’‘’zO ; ~R~Z,U~~’~~~,~R”~O~,~R”’O~,~R’‘’It is evident that the possible number of various combinations in this group is very great. Besides the above types, the author has obtained other compounds containing neither molybdenum nor tungsten ; for example : p hosp h o-vanada tes, arseno-vanadates, and aniimon y-vana- dates, which are frequently crystalline, and hare the general formula m ft’z05,nR’’z05,pR20.I), A. L.148 ABSTRACTS OF CHEMICAL PAPERS.I n o r g a n i c Chemistry.Critical Temperature and Pressure of Liquid Oxygen. ByS. WRORLEWSKI (Compt. rend., 97, 309-310).-When oxygen isliquefied by pressure in a bent tnbe surroutided by liquid ethylenewhich is caused to evaporate rapidly, it is found that, as the amountof liquefied oxygen increases so that it rises above the surface of theethylene, the pressure necessary to continue liquefaction graduallyincreases, and when the liquid oxygen rises t o a certain height in thetube, the meniscus becomes indistinct and finally disappears.Theseresults are due to the fact that the temperature of that part of thetube above the liquid ethylene gradually increases as the distancefrom the ethylene increases. The disappearance of the meniscus takesplace at a, pressure of about 50 atmos., and on slightly reducing thepressure the meniscus reappears.Carbonic anhydride was liquefied by pressure in a tube, the lowerpart of which was placed in melting ice, whilst the upper part washeated to 50°, the intermediate portions being of course at inter-mediate temperatures. As the liquefied gas approached the heatedportion of the tube, the pressure required to continue liquefactiongradually increased until at about 76 atmoa.the meniscus disap-peared, but it reappeared on slightly reducing the pressure and con-sequently reducing the volume of the liquid.The disappearance and reappearance of the meniscus in both casesevidently takes place at that part of the tube which is at the criticaltemperature for the particular gas, and the pressure observed at thetime of disappearance is the critical pressure. The critical pressurefor oxygen is about 50 atmos., and the critical temperature isapproximately - 113". C. H. BINORGANIC CHEMISTRY. 149Critical Point of Oxygen. By E. SARRAU (Compt. rend., 97,G9-490) .-The critical pressure and temperature calculated bymeans of Clausius’ formula from the results of Amagat’s experimentson the compressibility of oxygen, are 48.7 atmos., and - 105.4”respectively.These values agree fairly well with Wroblewski’sdeterminations (see preceding Abstract).Conduct of Moist Phosphorus and Air towards CarbonicOxide. By I. REMSEN and E. H. KEISER (Chenz. News, 48, 199-201).-In reference to the work of Hoppe-Seyler (dbstr., 1880, 3),Baumann (ibid., 1882,691), Traube (ibid., 1882, 795), and Leeds (ihid.,1880, 237), on the existence of an active form of oxygen distinct fromozone, the authors have repeated some of the experiments. A repeti-tion of Traube’s experiment led the authors t o confirm his statement,viz., that the oxidation of palladium-hydrogen is due to bhe formationof hydrogen dioxide. And again, several repetitions of Leeds’s andBaumann’s experiments, in which great care was taken to prevent themixed gases from inside the apparatus coming in contact with organicmatter, led the authors to negative Leeds’s and Baumann’s conclu-sions; under these conditions no oxidation of carbon monoxide todioxide took place.In these experiments ad1 the stoppers were covered with water ormercury, connections were made with pieces of glass tubing bent twicea t right angles, so as 00 avoid india-rubber joints, and all necessaryplugs were of asbestos.I n some experiments, the asbestos plugs werereplaced by cotton-wooll with the result that the gas which previouslycontained no carbonic anhydride, now precipitated baryta-water ; thisexplains Leeds’s error. No satisfactory explanation is given of thenegative results obtained by Leeds and Baumann when no carbonicoxide was used.The ant,hors are of opinion that the action of airand moist phosphorus on carbonic oxide furnishes no evidence of theexistence of the so-called active oxygen.C. H. B.D. A. L.Atomic Refraction of Sulphur. By R. NASINI (Gazzetta, 13,2 9 6 4 1 1 ) .-Bruhl’s labours on atomic refraction have shown thatthe same element may have different. atomic refractions according toits mode of union with the other elements, but up to the present timethe atomic refraction of sulphur in its various compounds has notbeen made the object of special study.After noticing what bas been already done i n determining therefractive indices of various sulphur compounds, the author pointsout that the questions he proposes to solve are:1.To ascertain the value of the atomic refraction of sulphur cor-responding with oxygen, where bivalent sulphur is united with twounivalent groups, as i n the mercaptans.2. Its atomic refraction where the two valencies of sulphur aresatisfied by the same carbon-atom.3. To ascertain whether a variation in valency has any influenceon its atomic refraction, by a study of inorganic sulphides and deri-vatives of carbon acids in which the sulphur is quadrivalent orsexavalen t150 ABSTRACTS OF CHEMICAL PAPERS.?a. ----5 ' 01.32.83.49.82 - 4The experiments were all made with liquids: these for the mostpart were supplied by Kahlbaum, but were purified before the deker-minations were made. The author employed the empirical formulan-1 used by Landolt and Bruhl, as being but little affected by varia-tions of temperature.H. A. Lorentz and L. Lorenz have recentlyshown (Wied. Ann., 9, 64, and 11, 70) that the formula 7is the correct expression for the refractive power of a substance ; itgives excellent results, and has also been used bg the author. Thevalues for this formula, calculated by Landolt from Bruhl's nume-rous experiments, are given in the subjoined table, where ra andrA represent the atomic refmctions of the elements with respect tothe line a of the hydrogen spectrum, and with respect to the con-n--1. stant A of Cauchy's formula as functions of the old formula - d 'and T ' ~ and r'* the same values for the new formula.9?? - 1n + 2 dr A .4.861-292-713.299-532'00Carbon c ..................Hydrogen H ..................Chlorine c1..................Increment for each double bond.. ........Oxygen (alcoholic) 0' ................ .. (aldehydic) 0" ................2-481.041.582.346-021*78?i-1d ' ~2'431.021-562-295.891.59n2-1(a: + 2)d'The determinations of the refractive index were nearly all made at20" with a spectrometer of Bartels and Diedcrichs, by the method ofminimum deviation, using the lines a, p, and y of the hydrogenspectrum and the D sodium line. The sp. gr. of the substance wasdetermined at 20°, referred to water at 4", reducing it t o a vacuum bymeans of the formula dt4 = - (2-1) +A, where rn is the weight of thesubstance at a temperature t, w that of the water at the same ternpe-rature, and X the mean density of the atmosphere.The substances examined were ethyl mercaptan, EtHS ; ethyl sul-phide, Et,S ; ethyl bisulphide, EtS, ; isobutyl mercaptan, C4H,.SH ;ethyl monothiocarbonate, OC(OEt)(SEt) ; isopentyl mercaptan,C,H,,.SH ; isopentyl sulphide, ( C5HI,),S ; diethyl dithiocarbonate,OC( SEt), ; carbon bisulphide, CS, ; the compound, CS( OEt), ; sul-phurous anhydride, SO, ; and sulphuric acid, H2SOa. The results aregiven in three tables, and from an inspection of them it appears thatthe atomic refraction of sulphur, like that of oxygen, has two values,according as the two vdencies are satisfied by two differeut univalentrnINORGANIC CHEMISTRY.151Sulphur with two single bonds .. . . . . . . . . ,, ,, a double bond . . . . .. .. .. . .groups, as in mercaptian, &c., or by the same carbon-atom as in carbonbisulphide. These two values are as follows :-ra . VA. r', . r'A. -- -- ---14 -10 13 -53 7 *87 7-6515-61 15-09 9.02 8-04n2- 1(.Z + 2)d'I n the case o€ the oxygenated compounds of sulphur, it wouldseem that the atomic refraction has only one value, although it differsconsiderably from those given above.It is now established that the atomic refraction of an element mayvar-y, not only as it is more or less closely united with other elements-that is, by single or double bonds-but also that the nature of theatoms or variation in the capacity of saturation of the element maygreatly influence the value of the refraction-constant. Comparativeresearches on other mnltivalent elements, such as phosphorus andarsenic, will no doubt throw light on this most important question.C.E. G.Basic Sulphates. By 5. HABERMANN (Monatsh. Chem., 4, 78i).-Preliminary Notice.-The basic copper sulphate, 6Cu0,2S03,5H,0,which Reindel obtained as a blue-green precipitate on adding ammo-nia in sufficient quantity to a boiling solutioii of normal cupric sul-phate (Gmelin-Kraut, 6 Aufl., vol. iii, p. 628), is also formed byboiling a solution of the normal sulphate (Pickering, C. J., 1883,Abstr., 853), and the author of the present notice has obtained it bytreating the solution of the normal sulphate with ammonia or withsodium carbonake in certain proportions.Basic sulphates of nickel, cobalt, zinc, and cadmium are formed inlike manner with either of these precipitants, but the salts thus ob-tained are not analogous in composition to the copper salt.Furtherdetails are promised. H. W.Action of Potassium Permanganate on certain Sulphur-compounds. By 11. HONIG and E. ZATZEK (nlonatsh. Chem., 4, 738-'752).-In this paper the authors describe a large number of expe-riments on the action of potassium permanganate on the thiosulphates,sulphites, and sulphides of the alkali-metals, the results of which maybe summarised as follows :-1. The thiosulphates of the alkali-metals are completely oxidisedby the permanganate at ordinary temperatures, only in alkaline solu-tion. Whatever may be the concentration of the permanganatesolution, the complete oxidation of 1 part sodium thiosulphate(Na$3,0,,5H20) requires 1.6366 part potassium permangsnate.Th152 ABSTRACTS OF CHEMICAL PAPERS.composition of the resulting precipitate is best represented by thefor mu1 a KH,Mn,O,.2. The s u l p h i t e s of the alkali-metsls are completely oxidised atordinary temperatures both in neutral and in alkaline solution. Thequantity of permanganate required for oxidation of I part by weightof sodium sulphite (Na,S03) depends on the concentration of thepermangsnate solution, being less in proportion as that solution ismore dilute, The composition of the resulting manganese precipitateis variable, m d likewise depends on the concentration of the per-manganate solution.3.The action of permanganate at ordinary temperatures on themono- a,nd poly-sulphides of the alkali-metals gives rise to sul-phuric acid, trithionic acid, and free sulphur ; at the boiling heat allor nearly all the sulphur is oxidised to sulphuric acid.Direct Union of Nitrogen and Hydrogen. By H. B. BAKER(Chem. News, 48, 187--188).-This communication is a reply toJohnson (Trans., 1881, 128,130). The author describes various expe-riments with Johnson's and other apparatus, and ultimately comesto the conclusion that nitrogen prepared from air, either by the removalof the oxygen by cold phosphorus, or by patassium pyrogallate, or byhydrogen in the presence of warmed platinum sponge, does not com-bine directly with hydrogen to form ammonia.When, however, thehydrogen was passed through a solution of silver nitrate, and subse-quently through three bottles containing a saturated solution offerrous sulphate, the author always obtained a brown coloration inthe second Nessler tube.Note.-Johnson has discontinued the use of silver nitrate for thepur$catiort of his hydrogen (Chem. News, 48,202).H. W.D. A. L.Nitrogen Iodides. By A. GUYARD (Compt. rend., 97, 526-531).-Nitrogen iodide in contact with water or aqueous ammonia is assensitive to luminous vibrations as to calorific, sonorous, or materialvibrations. When exposed to light, the iodide is rapidly decomposedwith effervescence and gives off pure nitrogen, ammonium iodide anda small quantity of ammonium iodate being also formed.I n presenceof water, the decomposition usually terminates in a violent explosion,but in presence of ammonia it proceeds quietly to the end. Nitroqeniodide is as sensitive to diffused light as to direct rays, the rapidity ofdecomposition being proportional to the intensity of the light. Thedecomposition takes place equally well a t lo, 5", lo", or the ordinarytemperature. The infra-red spectrum has no influence on the decom-position, but the visible spectrum acts powerfully, the maximumeffect being produced by the yellow rays and the minimum by theviolet.Nitrogen iodide of the composition NH, is decomposed by light inpresence of water, without explosion, in accordance with the equation2NBJ = NHJ, + N. Nitrogen iodide, however, rarely has thiscomposition, and usually contains a greater or lesser proportion ofother iodides.The compound therefore generally decomposes a t firstin accordance with the above equation, but explodes when the iodideINORGANIC CHEMISTRY. 153NH31, begins to decompose. The decomposition of the typical iodide,NH12, in presence of ammonia, takes place in accordance with theequation 5NH1, + = lONHII + 7N. One and the samenitrogen iudide will give off more nitrogen in presence of ammoniathan in presence of water; in the first case ammonium iodide isformed, in the second the diiodide.The decomposition of nitrogen iodide in ammonia may be usedphotometrically to determine the chemical and mechanical equivalentof light. The apparatus employed consists of a small flask with along neck graduated in cubic centimeters, and provided with astopper.The neck also carries a side tube similar to that of a Gay-Lussac burette. 1.27 gram of iodine is placed in the flask, which isthen completely filled with ammonia of 22", carefully stoppered, withexclusion of air babbles, and exposed to light. 1.27 gram of iodinegives off 33.5 C.C. of nitrogen. The final reaction is the same whethernitrogen iodide or a mixture of iodine and ammonia is employed, andwhether the mixture of iodine and ammonia is exposed t o light atonce, or time is given for the formation of nitrogen iodide. Thedecomposition takes place in accordance with the equation 13NH3 + 101 = 10NHIL + 3N.Preparation of Ammonium Iodide and Iodwte.-When a mixture ofiodine with excess of ammonia is exposed to light, nitrogen is givenoff, the free iodine entirely disappears, and ammonium iodide andiodate are formed.The ammonia is driven off and the liquid con-centrated, when the ammonium iodide cryddlises out, and the iodateremains in solution..When iodine is mixed with aqueous ammonia, part of the iodineforms ammonium iodide, and the remainder is converted into nitrogeniodide. Afterwards, in presence 0% light and an excess of ammonia,more ammonium iodide is formed and nitrogen is given off. The firstpart of the change is chemical, the second photochemical. The principalreaction is represented by Odling'sequation 3NH3 -t 21, = 2NHJ +NH12. When the iodine is in excess, ammonium diiodide is formed,and the nitrogen iodide produced has approximately the compositionNHJ ; with proper proportions of iodine and ammonia, the nitrogeniodide has approximately the composition NHI, ; with an excess ofammonia, a greater proportion of ammonium iodate is formed.Nitrogen iodide of the composition NHI, is but slightly affected bywashing with pure water.Ammonia added to ammonium diiodideforms nitrogen iodide with the second atom of iodine.Under ordinary conditions, z(NH,O) + 233(NH40) + I,, =NH,O,I& + 154NHdI + 10(N8Hg115) + 227H0 + x(NH40),* whereaNHIO represents the excess of ammonia which must always beused, is the simplest equation which expresses the observed facts.The formula N,HgIl5 is approxima'tely 8NHIz. With twice the excessof ammonia, about twice the amount of ammonium iodate is formed,and the nitrogen iodide consists mainly of N,H,15, or approximately3NH I,.The formulae given by previous investigators are probablycorrect, b u t refer to bodies prepared under different conditions.* This equation is given exactly as it is in the original, it is, however, incorrect,aa the two sides are N233,H932,1303,(328 = N:36,H93pT305,0Q39.YOL. XLVI. 154 ABSTRACTS OF CIIEMICAL PAPERS.Nitrogen iodides are decomposed even by very dilute sulphuric,hydrochloric, or sulphurous acid, a t first with effervescence, butafterwards with violent explosion. They dissolve in sodium thiosul-phate, with formation of sodium iodide, ammonium snlphate, and freeammonia. The free ammonia is that existing in the nitrogen iodide ;the ammonium in the ammonium sulphate is derived from thenitrogen existing in the nitrogen iodide in the form of triiodamine.Nitrogen iodide is partially decomposed by potassium iodide in thedark, with formation of potassium diiodide free from ammonia, and anitrogen iodide insoluble in the alkaline iodide, that is, the iodide NHI,loses an equivalent, or part of an equivalent, of iodine, and yields anew iodide.When exposed t o light, however, the nitrogen iodide iscompletely decomposed by the potassinm iodide, and the liquid con-tains ammonium iodide. Potassium cyanide dissolves nitrogen iodideeven in the dark, with evolution of nitrogen.Nitrogen Copper Iodide.-When an ammoniacal solution of a coppersalt is mixed with potassium diiodide, a brilliant, crystalline, garnetLcoloured precipitate of the composition Cu12,2NH21 is graduallydeposited.When dried, this compound is very stable, but it isentirely decomposed by water, with formation of ammonium diiodide,and a bronze-coloured cupric oxyiodide, CuOJ, which is decomposedby heat into black cupric oxide, iodine, and oxygen. The doublecopper nitrogen iodide is decomposed by aqueous ammonia, with for-mation of an ammoniacal solution of cupric iodide and a residue ofan explosive nitrogen iodide free from copper. When the doubleiodide is heated, iodine and the products of the decomposition ofnitrogen iodide are given off, and a residue of perfectly pure cuprousiodide is left. When distilled, the double iodide yields cuprousiodide, and brown, violet, and ammoniacal vapours.The brownvapours condense to a black product, decomposed by water witohformation of a black crystalline nitrogen iodide, which resemblesiodine in appearance, but which differs from all the other nitrogeniodides by dissolving with effervescence in a solution of potash orsoda, nitrogen or hydrogen being given off, and a, considerable quan-tity of ammonia formed.When Schweitzer’s reagent, prepared by Peligot’s method, is mixedwith potassium diiodide, a crystalline black double iodide of nitrogenand copper is formed, which resembles the preceding compound in itsgeneral properties, but yields an explosive cupreous residue whendecomposed by washing with water.By I.REMSEN and E. H. REISER (Chem.News, 48, 201--202).-1n course of the experiments alluded to inthis vol, p. 149, the authors had a suspicion that the phosphoruswith which they were working might have contained some carbon-aceous matter. To remove this the phosphorus was distilled in anatmosphere of purified hpdrogen, and the vapour condensed in coldwater. The distilled phosphorus presented a peculiar appearance ; itfloated on the surface of the water, forming a snow-white layer, andwhen placed in warm water changed into ordinary phosphorus. Aftermany experiments the authors found that this variety of phosphorusC. H. B.White PhosphorusINORGANIC CHEMISTRY. 155could be prepared in the following manner : Sticks of phosphorus areplaced in a tuhulated retort, the neck of which is inclined upwards,and projects into a double-necked globular receiver, containing alayer of water and ice 18 in.deep in the deepest part. The receiveris supported in a vessel of cold water, and the bent tube, which passesfrom the other neck of the receiver, dips into cold water. A glasstube is fitted into the tubulure of the retort to supply purified hydro-gen, which is passed until the apparatus is filled with i t ; the currentis then stopped, and the distillation proceeded with ; this is conductedsteadily so that the vapour as it issues from the retort does not con-dense to a liquid. In successful operations a thin white cake is foundfloating on the water. The apparatus is allowed to cool, the retortdisconnected, and the receiver with its contents put under water todisplace the hydrogen and remove the phosphorus ; if this precautionis not taken, the phosphorus is liable to take fire, and give rise to anexplosion of the mixture of hydrogen and air.White phosphorus islight and plastic ; if it is placed on bibulous paper as it dries, itfumes, melts without taking fire, and changes to ordinary phosphorus,with which its melting point is identical. It iR soluble in carbonbisulphide, and is not affected by sunlight so readily us ordinaryphosphorus ; a sample after a year became slightly yellow, but wasotherwise unchanged. I). A. L.By A. GAVAZZI(Gazzetta, 13, 324-325) .-0 n passing gaseous hydrogen phosphidethrough a neutral aqueous solution of platinic chloride, an ochreousyellow precipitate of the composition PtPHz is obtained: this isinsoluble in water and hydrochloric acid.It ignites when heated to100-llO", or when moistened with fuming nitric acid.Arsenic phosphide, ASP, is formed by the action of hydrogen phos-phide on a solution of arsenious anhydride in hydrochloric acid.An aqueous solution of potassium permanganate absorbs hydrogenphosphide at a low temperature, the reaction being represented byequations-Reactions of Gaseous Hydrogen Phosphide.PH, + 2RMnQa = KzHPOs + 2MnOz + HzOPH, + 2KMnOd = KzHPOd + Mnz03 + H20.C. E. G.Preparation of Phosphorus Oxychloride. By E. DERVIN(Compt. rend., 97, 576--578).-When phosphorus trichloride is mixedwith potassium chlorate a violent reaction takes place, phosphorusoxychloride and potassium chloride being formed in accordance withthe equation KC10, + 3PC1, = 3Pocl3 + KC1. This reaction maybe utilised for the preparation of phosphorus oxychloride. 500 gram8of pure phosphorus trichloride free from uncombiried phoPphorus areplaced in a retort of 750-1000 C.C.capacity, connected with aninverted condenser, and 160 p m s of finely powdered potassiumohlorate is added through the tubulure i n quantities of about 4 gramsst a time, care being taken to wa.t each time uirtil ebullition ceasesbefore adding more chlorate. When the whole of the chlorate has beenadded, the liquid is distilled. The yield is very satisfactory, and theoxychloride contains but mere traces of chlorine. C.H. B.m 156 ABSTRACTS OF CHEMICAL PAPERS.Action of Sunlight on Phosphorous Anhydride. By A.IRVING (Chem. News, 48, 173).-The author prepared his phosphorousanhydride by passing a slow current of dry air over molten phos-phorus, and found that the product turned brown, and changed intofree phosphorus and phosphoric anhydride when exposed in sealed tubesto direct sunlight (compare Lewes, Trans., 1884, 10). D. A. L.Boron. By A. JOLY (Cornpt. rend., 97, 456-458).-The productsof the reduction of boric anhydride by aliirninium are : (1.) Theboride, BAl, which forms golden-yellow hexagonal lamellze, describedby Deville and Wohler. (2.) The boride, B6A1, which forms largeblack la,mells, analysed by Hampe (Annnlen, 183, p. 75).(3.) Yellowquadratic crystals of adamantine lustre containing carbon and alu-minium. (4.) A boron carbide, or more probably several carbidesformed by the alteration of the preceding compounds, at a high tem-perature, in presence of carbon and excess of boric anhydride. Thiscarbide forms small black very hard crystals, with a bright metalliclustre, insoluble in boiling nitric acid. They have a sp. gr. of2.542 a t 17", and contain 15.7 per cent. of carbon, correspondingwith the formula B,C. C. H. B.New Silver Compounds. By T. POLECK and K. TH~~MMEL (Ber.,16, 2435-2448) .-Gutzeit has shown (Plznrm. Zeit., 1879, 263) thatwhen gases containing arseniuretted hydrogen impinge on a piece offilter-paper moistened in its centre with one drop of a concentratedsolution of silver nitrate, the wet spot assumes a lemo~-yellow colonr,whilst a t the periphery a brownish-black ring forms, which slowlybroadens towards the centre until the whole spot becomes black.Ifthe spot, whilst still yellow, is moistened with water, it blackens overthe whole surface, and a t the same time shows a strongly acid reaction.Hydrogen sulphide, phosphide, and antimonide give similar results.The present paper details experiments on the chemical nature of thesereactions.Hydrogen sulphide is passed into a concentrated solution of silvernitrate (1 part AgNO, in 0.7-1.0 part, water) kept constantly agitated,when a yellowish-green precipitate of the formula Ag2S,AgNOa is ob-tained. The supernatant liquid has a strongly acid reaction, does notcontain sulphuric acid, and yields a considerable quantity of ammoniawhen distilled with potash.The precipitate can be heated to 180"without decomposition, and then forms a dark-green powder. It isdecomposed into silver nitrate and silver sulphide by treatment withwater or alcohol. On oxidation with nitric acid of sp. gr. 1.18 anorange-red coloured powder is frequently obtained. This compoundis also obtained by the action of sulphur on a boiling concentratedsolution of silver nitrate, and after purification gave results corre-sponding with the foraiula Ag,S, Ag,S04. It dissolves in boilingnitric acid, is decomposed by boiling water into silver sulphide andsulphate, and by cold hydrochloric acid into silver sulphide andchloride.Arsenic trihydride acting on dilute solution of silver nitrate haslong been known t o yield metallic silver, arsenious anhydride, anINORGANIC CHEMISTRY.157nitric acid; with a concentrated solution, however, the reaction isvery different. The first few bubbles of gas produce a deep lemon-yellow coloiation, no precipitate is formed, and the liquid acquiresan acid reaction; this colomtion remains for one or two devs,then the liquid becomes colourless, silver is precipitated, and thesolution contains arsenious m d arsenic acids. If a r,ipid stream ofarsenic trihydride be passed into a concentrated solution of silvernitrate a t O", the whole liquid solidifies to a yellow crjstalline mass,but rapidly blackens from separation of silver.Many experimentswere tried to isolate tbe compound, but its instability was toogreat. Analysis by an indirect method pointed to the formulaWith Concentrated solutions of silver nitrate, hydrogen phospbidegave results exactly similar in appearance to those obtained witharsenic trih ydride. The composition of the yellow precipitate fromindirect determinations was Ag3P,3 A gN 0,.d ello ow precipitate is also obtained by the action of antimony hri-hydride on concentrated solution .of silver nitrite. It could not beisolated, but indirect determinations gave the formula Ag,Sb,3AgN03.Unlike arsenic, phosphorus, and sulphur, metallic antimony does notyield the double compound ; when it is placed in a solution of silvernitrate, A@b is first formed, but is soon converted into antimoniousoxide and silver.A. J. G.Ag3 AS. 3 AgN03.Silver Nitrite and Ammonia. By A. REYCBLER (Bey., 16,2425-2428) .-On dissolving silver nitrite in concentrated aqueousammonia heat is evolved, aud the liquid soon deposits well-formedbrilliant yellow prisms of the formula AgNO,,NH,, soluble in water,sparingly soluble in alcohol, nearly insoluble in ether, and melt.ing at70". Long-continued heating above the melting point decomposesthe compound, all the ammonia being expelled, and the residue con-sisting mainly of silver nitrite. On gently heating the compoundwith ethyl iodide, it yields silver iodide, ethyl nitrite, and ammonia.On heating the nionammonia compound with alcoholic ammoniaand precipitating with ether, the diammonia compound SgNO,[NH,),is obtained as a white crystalline mass, rapidly losing ammonia onexposure to air.The finely powdered monammonia compound rapidly absorbsammonia gas, with considerable evolution of gas, and apparentlyyields a triammonia compound, AgN02(NH3), ; it, is readily solublein water, and rapidly loses ammonia on exposure to the ah.Crystallised Calcium Silicophosphate produced in theDephosphorisation of Iron.By A. CARNOT and RICHARD (Comptqserid., 97, 316--320).-The slag formed in working the Thomas-Gilchrist process at Joeuf (Meurthe-et-Moselle) has a brownish 01.blackish colonr, and is more or less crystalline, some parts consistingof transparent crystalline matter, which acts strongly on polarisedlight, whilst other parts have a reddish colour, and resemble brownImmatite. The surface of the slag is covered with black crystals,some of which are slender needles, whilst others are right' rhombicA.J. a158 ABSTRACTS OF CHEMICAL PAPERS.prisms with brilliant faces. These crystals are frequently aggregatedin columnar masses, which terminate i n small vitreous perfectlytranslucid blue crystals. Similar blue crystals are found in thecavities in the slag, and appear to form one of its principal con-stituents. These are very constant in composition, but frequentlyenclose small black needles or particles, which can, however, beremoved by means of a magnet. The blue crystals have h e com-position-Pz05 SiO,. Al2O3. CaO. MgO. FeO. MnO.29.65 16-42 2.76 53.20 traces 1.80 traces = 99.83.Vanadium could not be detectred. The numbers correspond with theformula 8P,0,,8SiOa,A1,0,,Fe0,36Ca0.Regarding the crystals asconsisting essentially of calcium silicophosphate, the formula becomesP,05,Si02,5Ca0 or Ca,P20B + C%,SiO,. The composition of thecrystalline slag is variable ; it contains a lower proportion of phos-phoric acid than the blue crystals, and a considerable excess of ferrousand manganese oxides.The calcium silico-phosphate crystals belong to the rhombic system,the angles being riam = 113” 10’ and e’e’ (on p ) = 64’. They arestrongly doubly refractive, and exhibit well-marked dichroism. Whenthe plane of their optical axis is parallel with the principal section ofthe Nicol’s prism, they have a cobalt-blue colour; when i t is perpen-dicular, they are almost colourless. C .H. B.Presence of Yttrium in the Sphene of Biellese Syenite. 13;.COSSA (Gazzetla, 13, 326)’.-The author has found yttrium arid ceriumin the sphene of Biellese syenite to the amount of about 2.3 per cent.This is an important fact, as it affords additional evidence of theanalogy between the syeiiite of Biellese and those of Planceuschen-giund and Sweden. Besides showing that substances exist in theAlps which were formerly believed to be exclusively confined toNorthern Europe, it proves that these rare metals are widely diffused,and their association with calcium compounds may be important inrelation to their valency. C. E. G.Separation of Gallium.By L. DE BOWBAUDRAN (Compt. rend.,97, 295-297, and 521--522).-From Vanadium-(I.) The feeblyacid hydrochloric acid solution is mixed with arsenious acid and anexcess of acid ammonium acetate, and treated with hydrogen sulphide.Vanadium is not precipitated, but the arsenious sulphide carries downthe whole of the gallium. The precipitate is washed with water con-taining ammonium acetate and hydrogen sulphide, and treated withaqua regia. The arsenic acid is reduced with sulphurous acid, and acurrent of hydrogen sulphide is passed through the strongly acidliquid, when the arsenic is precipitated alone, all the gallium remain-ing in solulion. This is the only process which gives accurate resultswhen used alone, and it is especially useful fur separating smallq-ntities of gallium from large quantities of vanadium.(2.) ThINORGANIC CHEMISTRY. 159solution is almost neutralised with ammonia, mixed gradually with anexcess of ammonium sulphide, and agitated. Dilute hydrochloricacid is then added in considerable excess with constant agitation, andthe precipitated vanadyl sulphide is filtered off and washed withdilute hydrochloric acid containing hydrogen sulphide. The filtrateis boiled with aqua regia to destroy ammonium salts, the nitric acid isthen expelled, and precipitation repeated six or seven times. Thevafiadyl sulphide is also dissolved in aqua regia, and reprecipitatedseveral times. (3.) The hydrochloric acid solution is made alkalinewith ammonia, and boiled until the liquid is neutral.The precipitateis redissolved and reprecipitated two or three times ; the filtrake istreated by method (1) in order to separate the last traces of gallium.(4.) The solution is mixed with sulphuric acid and ammonium sul-phate in proper proportions, and the gallium alum is purified byrecrystallisation.If the amount of gallium is very small, process (1) is used ; if theproportion of gallium is large, and that of vanadium small, the greaterpart of the gallium is removed in the form of alum, and the mother-liquid is treated by the following method. When the gallium andvanadium are present in approximately equal proportions, khe liquidis twice boiled with ammonia (2), and the filtrate treated by (1).The precipitated gallium hydroxide is converted into alum, and themother-liquor is again boiled with ammonia.The filtrate is treatedby (1) : the precipitate is mainly converted into gallium alum, andthe mother-liquor is finally treated by (1).From Tungsten.-The tungsten is converted into alkaline tnngstate,and the solution evaporated almost to dryness at a gentle heat in pre-sence of a considerable excess of hydrochloric acid, a small quantityof water is then added, and the liquid again evaporated almost todryness. The residue is treated with a moderately large quantity ofvery dilute hydrochloric acid, gently heated, and the liquid filtered.The filtrate is free from tungsten; the traces of gallium in theprecipitate are removed by dissolving it in ammonia, and repeatingthe process.From Phosphoric Acid.-(1.) The gallium is precipitated by potas-sium ferrocyanide in presence of a large quantity of hydrochloric acid,and the precipitate is washed with water strongly acidified withhydrochloric acid.(2.) The solution is mixed with about one-thirdits volume of strong nitric acid, and the phosphoric acid precipitatedby meam of ammonium molybdate, the gallium and molybdenumbeing afterwards separated by the method previously described.(3.) The feebly acid solution is mixed with arsenious acid andammonium acetate, and treated with hydrogen sulphide, as describedabove. C. H. B.The solution contains small quantities of gallium.Diffusion of Vanadium in the Mineral and Vegetable King-doms. By L. RICCIARDI (Gazzetta, 13,259-262).-After a recapitu-lation of the results obtained by various authors on the occurrence ofvanadium in rocks and minerals, the author gives the results of hisown experiments on the existence of that metal in volcanic emana-tions ancient and modern.These are as follows, the numbers denot160 ABSTRACTS O F CHEMICAL PAPERS.i n g the percentage of vanadium sesquioxide found in the severalsubstances examined :-Lava of Vesuvius (1 868) ........Y , ,, (1871) .........7 , ,, (1872) . . . . . . .Ashes from Vesuvius (18i.2) ....Lava of Vesuvius (1851) ........Lava of Etna (1669) ............7 9 ,, (18’79) ............Basalt of Pachino ..............Basalt of the Isola dei Ciclopi.. .....0.0063 per cent.0.0075 ,,0.013 ,,0.105 ,,0.0081 ),~0.0102 , 70.0034 ),0.006 ,,0.0084 ,,Scacchi has found vanadium in incrustations of the Vesuvian lavaof 1631.E.Rechi (Atti della It. Accademia dei Lincei [3], 3,403 [1878-79]),after having found this element in argillaceous limestones, in schistsand in sands, has established its presence in plante, especially i n thosegrowing on clay soils.The author of the present paper bas also found it in the ashes ofgrasses growing on the Etna lava of 1660, b u t the proportion was toosmall for qnantitative estimation. Its occnrrence in plants may beregarded as having some relation to the isomorphism of vanadic andphosphoric acids. H. W.Sulphur Compounds of Molybdenum. By G. KRGS (Ber., 16,2044--2051).-According to Berzelius, molybdenum forms not onlyR di- and tri- but also a tetra-Pulphide, MoS,, a compound which wouldpoint to molybdenum as possessing a quanticalence of eight, andwould be analogous to the uranium tetroxide.The author has sue-ceeded in isolating this tetrasulphide by melting molybdic acid withpotassium carbonate, exhausting the melt with water, and passinghydrogen sulphide into the solution when heated to the boiling point.A black powder together with a crystalline substance separates out.This mixed material is washed first with cold water, then with hotwater to dissolve out the molybdennm di- and tri-sulphide, and theresultant chocolate-brown powder is heated in a current of hydrogensulphide until its weight is constant. The result of the analysisshow that this substaiice is molybdenum tetraadphide.The author also describes a series of compounds intermediatebetween the salts of molybdic and sulphomolybdic acids, which maybe designated by the generic term oxythirmolybdates.Ammonium o r t l ~ o x ~ t h i o i ~ ~ ~ l y b d ~ r t e , prepared by passing hydrogensulphide into an ammoniacal solution of ammonium moly bdate, crys-tallises in golden-Fellow needles of the composition (NH&Mo02S,,which was assigned to the substance by Debray.The correspondingpotassium salt, forms reddish- golden needles.Besides the crystalline orthoxythiomolybdnte, a number of amor-phous oxysnlphomolybdates are obtained by the decomposition of themolybdates by the alkaline hydrosulphide. Ammonium pyroxy-thiomolybdate, prepared by decomposing ammonium moly bdate withammonium hydrosulphide, is a reddish-golden precipitate having thtINORGANIC CHEMISTRY.161composition H,Mo,O,S, (= 2H2Mo0,S2 - H2S), which evidentlystands to orthoxymolybdate in the same relation as ortho- t o pyro-phos-phoric acid. The corresponding sodium salt is a golden amorphouspowder.Thiomollybdates. - These compounds were obtained by Berzeliusby passing hydrogen sulphide into the tnolybdates and evaporatingthe liquid; the substances formed by t,he process are, however, farfroin pure, owing to a loss of hydrogen sulphide and formation of theoxythiomolybdates. The potassium salt c m best be prepared byfusing together potassinm carbonate, sulphur, aiid a large excess ofthe natural molybdenum sulphide.Bit hio )n o 2y bclat es.-On passi rig hydrogen sul phid e into a solutionof potassium molybdate containing a large excess of free alkali, anorange-yellow precipitahe separates out ; this has the compositionKGMo2S9, or potassium dithionwly bdute. V. H. V.Complex Inorganic Acids. By W. GIBBS (Chew. News, 48,155) .--Two communications from ,the author on this subject havealready appeared in this Jonrnal (Abstr., 1882, 469, i O 2 ) . In thesecommunications only binary compounds have been referred to, andthese can be represented by the general formula:-mR~03.nR’205.~RJ‘z0,in which m = any even number from 10 to 48 ; R = either molybde-num or tungsten ; R’ either phosphorus or arsenic ; and R” the basicradical. He has now extended the genesalisation, and states that thephosphorus and arsenic may be replaced by vanadium or antimony,or possibly by niobium acd tantalum ; for example, well-defined andbeautifully crystalline vanadio-moly bdates have been obtained haringthe formulae :-~ M o O , , V , ~ ~ , ~ A ~ ~ O , H ~ C ) + 4Aq.16Mo03,V20,,5Ba0,H~0 + 28Aq.Moreover, ihe group R’?05 may be replaced by the group R,O, asAs,O,,Sh 0 Thus the formula of an ammo-nium phosphoroso-molybdate is -O,, and probably V,O,.243100, 2PzO3,5Am20 + 20Aq.These R,03 compounds are converted by oxidation into the salts con-taining the group R205. Klein has described salts containing R,03 ;salts of this class containing hypophosphorous acid have also beenobtained, such as the ammonium hypophosphomolybdate of theformula 24Mo03,6P02,6Am20 + 7Aq. There are a great manyternary compounds of a similar character containing moljbdic ortungstic oxide united with two other oxities. A great many have thegeneral formula, mR03ri,R’205,~~R’205rrRJ’?0, in which RO, = molybdicor tungstic oxide, whilht R’2@5 and R”O5 = two different oxides of thesame type ; for example, P2O5 and V,O,. It has not as Jet been provedthat any two known oxides of the type R205 can enter together intosuch compounds. The following are some examples of these salts :162 ABSTRACTS OF CHEMICAL PAPERS.14M003,8Vz05,Pz0,,8Amz0 + 50Aq.48MoO3,V205,2PzO6,7Arn20 + 30Aq.60W03,Vz05,SPz05,10Am20 + 60Aq.But the compounds containing Moo3 or WO, in combination withoxides of two types are still more numerous. They have the follow-ing general formulae :-16~03,3V205,P20,,5A~lzO + 37Aq.rnR03,nR’~051pR”z03,rR”‘z0 ;mR03,nR’2U5pR20;~,rR’‘’z0 ;in which Rz05 may be Pz06, V205, As,05, Sbz05, and probably NbZ05and T%05, whilst RzOs may be B303, P203, V&, Asz03 Sbz03. Theauthor has also prepared salts belonging to the ternary compoundswith the general formula mR03,nRz05,pR”Oz,rR”’02. None of thisseries containing R‘*03 in place of R20a have as yet been prepared.Quarternary compounds also exist, for the author has obtained thefollowing in well-defined crystals :-GO WO3,3P2O~,V2Q~,V0~,18€3a,Q + 150H,O, which is reducible to the general formula :-mR03,nR”~05,~R’zOa,rR’‘’zO ;~R~Z,U~~’~~~,~R”~O~,~R”’O~,~R’‘’It is evident that the possible number of various combinations in thisgroup is very great. Besides the above types, the author has obtainedother compounds containing neither molybdenum nor tungsten ; forexample : p hosp h o-vanada tes, arseno-vanadates, and aniimon y-vana-dates, which are frequently crystalline, and hare the general formulam ft’z05,nR’’z05,pR20. I), A. L