INORGAXIC CHEMISTRY. I n or g a n i c C h e m i s t r y . 11 Conversion of Calcium Hypochlorite into Calcium Chlorafe. By G. LUNGE (J. SOC. Chem. h d , 4, 722--724).-1t has already been shown by the author that the reaction 6Ca0C12 = 5CaC12 + Ca(C10& does not take place completely and without considerable loss of oxygen, except in presence of an excess of chlorine, idthough that chlorine does not appear in the equation. The author’s experiments point to the following conclusions :-The most13: ABSTRAOTS OF CHEMICAL PAPERS. favourable way of converting hypochlorite into chlorate is t o raise the temperature of the solution, and simultaneously have an excess of chlorine present therein. A large excess of chlorine is useless, perhaps i-sjurions, for the yield of chlorate.On the large scale, it is not necessary to raise the temperature by artificial means, the heat produced by the reaction being sufficient to complete it. The con- version at the ordinary temperature proceeds almost at once to the limit of about 70 per cent., but subsequently makes very slow pro- gress, so that it is impracticable to wait for its completion without heating. D. B. A Crystalline Silico-carbonate from Soda Liquors. By C. RAMMELSBERG (CYhem. Id., 9, 110-11 l).-Two specimens of crystals removed from the pump of a carbonating tower at the " Hermannia " Chemical Works at Schonebeck had the following composition :- COz. Si02. AlZO3. CaO. Na,O. HzO. I. 22.75 14-99 7.38 13.28 22-37 19.23 = 100 11. 21.50 15-00 8.03 12.41 21.66 21.40 = 100 Allowing for adhering soda liquor, these numbers lead to the formula Na18Ca6A12(Si,C)210R3 + 3oH20, or the substance is a, com- pound of the isomorphous normal carbonates and silicates 3 [3Nh( Si, C) 0,,2Ca (Si, C) Oy ],2A1( Si, C),O,,.The crystals are rhombic, exhibiting the form of the primary pyramid with its acuter terminal edges truncated, or frequently a tabular form due to the development of the end face ; the ratio of the axes is 0.5295 : 1 : 1.73. These crystals were first observed in 1880, but the specimen then analysed contained an admixture of gay-lussite, and the silica and alumina were not recognised as essential constituents. X. J. $. Sodium-calcium Carbonates from the Soda, Manufacture. By C. REIDEMEISTER (Chem. Ind., 9, lll).-In the Chemische Iyadustrie for 1884 the author described the rhornbic crystals analysed by Ram- melsberg (see preceding Abstract) as a hydrated sodium calcium carbonate.They are now found to occur in both the crude and car- bonated liquors. In the former, in which formerly only gay-lussite had been recognised, they have now been observed with crystals of gay-lussite deposited on their surfaces. The gay-lussite crystals are chiefly deposited from liquors in process of cooling; the silico- carbonate from those undergoing slow evaporation. M. J. S. Double Nitrites of Caesium and of Rubidium. By T. ROSEN- BLADT (Bey., 19, 2531-2535).-The double nitrite of cesium and eobalt, ~CSNO,CO(NO~)~ + H20! is formed by boiling equal parts of cvbztlt nitrate and sodium acetate in water (15 parts), filter- ing, and adding to the cold solution first acetic acid (20 parts), and then a, strong solution of sodium nitrite until tho liquid has an orange cdour, it irs then filtered, and treated with a solution of aINORGANIC OHEMISTRT.13 eaesium salt. The double salt 3RbN02,Co(N02), + HzO is prepared in a similar manner. They are both lemon-coloured crystalline salts, and resemble in their behaviour Fischer's potassium-compound, except in their solubility in water, the czesium salt dissolving only in 20,100 parts of water at 17", and the rubidium salt in 19,800 parts of water. The method employed in analysing these compounds is described. Thallium also yields a double salt with cobalt nitrite ; it is a red crystaliine compohd, soluble in 23,810 pai.ts of water. . N.H. M. Decomposition of Glass by Carbonic Anhydride condensed on its Surface. By R. BUNSEN (Ann. Phys. Chem. [2], 29, 161- 165) .-Formerly the author attributed the absorption of carbonic anhydride by glass-wool rather to an interpenetration of the glass by the molecules of the liquefied gas rather than to any chemical change (Abutr., 1884, 146). This view would also be confirmed by the obser- vations on the stability of glass towards the most concentrated hydro- chloric acid. However, if the glass-wool be damp, whereby the absorption of the gas is remarkably increased (Abstr., 1885, 867), the possibility of a chemical change is not precluded. Accordingly the glass (49.453 grams) used in the experiment was exhausted with water, and a residue obtained from it corresponding to the decompo- sition of 2.882 grams of glass, or 5-83 per cent.of the whole. Even if the chemical change consists in the production at first of sodium carbonate, which would take up a further quantity of carbonic anhydride, corresponding with the formation of sodium hydrogen carbonate, which on subsequent heating would again be driven off, yet all the carbonic anhydride absorbed caunot be accounted for in this way. The phenomenon is thus not only one of chemical change, but also of absorption, the particular degree of each of which cannot be estimated. If, then, carbonic acid can decompose glass, the same is to be expected of water. Observations in the course of experiments on the determination of the tension of aqueous vepour at high temperatures are quoted to show that glass tubes containing water-vapour when heated at 88" are converted into n white porcelain-like mass, and that their inner diameter is diminished by one-tenth.Note.-On the decomposition of glass by carbonic anhydride under high pressures compare Pfaundler (Abstr., 1885, 868). Purification O f Yttria. By L. DE BOISBAUDRAN (Compt. rend., 103, 627-629).-A comparatively very pure sample of yttria was sub- jected to 32 series of fractionations by means of ammonia. The product of the last precipitation of the thirty-second series showed 8 less brilliant fluorescence than the original earth, and the bands of Za and 2/3 in the spectrum had diminished considerably in intensity, whilst the bands of samarium retained their original vigour. The colour of the fluorescence had changed from y ellowish-green to orange- yellow.This last precipitate was submitted to 26 series of fractionations by meam of oxalic acid. The brilliancy of the fluorescence continu- V. H. V. V. H. V.14 ABSTRACTS OF CHEMICAL PAPERS. ally diminished, but, contrary to the phenomena observed during the first fractionation, the samarium bands diminished in intensity much more rapidly than the bands of Za and ZP. The earth from the oxalate precipitated at the end of the fifth fractionation showed very faintly the citron band and the double green band of Za and ZP, with a trace of the red bands of samarium. The oxalate from the twenty-sixth fractionation yielded a very white earth which showed a trace of the citron band of Za, but none of the red, green, blue, and violet bands in the spectrum described by Crookes.This yttria gave no fluorescence when mixed with lime, but its hydrochloric acid solution gave a brilliant spark spectrum of yttrium. The sulphate prepared from the last precipitate f ~ o m the fractiona- tion with oxalic acid gave a rose-coloured fluorescence due to the presence of a trace of bismuth. Heating and Cooling of Cast Steel. By OSMOND (Compt. rend., 103, 743-746) .-The phenomena which accompany the heating and cooling of cast steel were investigated by means of a thcrmo- electric couple connected with an aperiodic galvanometer. Barrett observed that when a bar of hard iron is cooled from a white heat there is a sudden development of heat at dull redness, and the magnetic properties of the iron change abruptly.He distin- guished this phenomenon by the name recalescence. Chatelier and Yinchon found that at about 700" a molecular modification of pure iron is formed. The author's experiments show that as the proportion of carbon increases from 0.16 to 1-25 per cent. the temperature at which the molecular alteration takes place falls, whilst the point of recalescence rises, until in hard steel the t v o points coincide. The rate at which heating takes place has no influence on the temperature at which the two changes take place, but these temperatures are affected by the rate of cooling, and are lower the greater the rapidity with which cooling takes place. In quick tempering, no such phenomena are observed ; the heat corresponding with the non-effected changes remains in the iron.The two critical points also fall somewhat if the initial tem- perature of heating is raised. During annealing after tempering, the latent heat of tempering is liberated gradually and not abruptly. By T. KNIESCHE (Chenz. Zeit., 10, 1067--1068).-1n treating tungsten ores, sodium tungstate is first obtained, then from this tungstic acid, which i n its turn is reduced at a temperature of 1600" to metallic tungsten. The preparation of the chemically pure metal is simply a question of time; any way, as obtained at present, it is useful in steel making. It must be added only when the irou is in it perfectly fluid state. Sodium tungstate is used for rendering inflam- mable materials fireproof. C. H. B. C. H. R. Tungsten. D.A. L. Titanium. By 0. v. PFORDTEN (AnnuZen, 234, 257--299).-The sulphides of those metals which have a strong affinity for oxygen cannot be obtained in the pure date by passing carbon bisulphide over the metallic oxides at a red heat, but they can be prepared by theINORGANIC CEEMISTRY. 15 action of pure sulphuretted hydrogen on the metallic chlorides. The gas must be passed through chromons chloride to remove traces of oxygen, and is then dried by means of phosphoric oxide. The author disputes Thorpe's statement (Trans., 1885, 492) that sulphuretted hydrogen can be dried by passing thegas through sulphuric acid. At the ordinary temperature, sulphure tted hydrogen reduces titanic chloride to titanous chloride ; at a higher temperature, a compound is precipitated, which is probably a sulphochloride.Crystals of titanium disulphide, TiS2, are deposited when sulphuretted hydro- gen and the vapour of titanium tetrachloride are passed through a red-hot tube from which atmospheric air has been carefully expelled. The bisulphide is not attacked by hydrogen at a red heat in the presence of an excess of sulphuretted hydrogen. A t a red heat, it is oxidised completely by carbonic anhydride, and it splits up into the sesquisulphide, Ti2&, and sulphur in an atmosphere of hydro- gen or nitrogen. The sequisulphide is a metallic grey substance, insoluble in sodium hydroxide solution; it dissolves in nitric and strong sulphuric acids with a green coloration. The author is of opinion that the sesquisulphide described by Thorpe (Zoc.cit.) is an impure Rubstance, and that its green colour is due to the presence of vanadium. The sesquisulphide is reduced to monosulphide by hydrogen a t a higher temperature than that at which refractory glass softens. The crystals of the monosulphide are dark red. Dilute nitric acid attacks the monosulphide with difficulty ; in other respects, this substance Atomic Weight of Germanium. By L. DE BOISBAUDRAN (Corn@. rend., 103, 452--453).-Winkler's recent determination of the atomic weight of germanium, 72.32 (hbstr., 1886, 985), agrees perfectly with the value calculated by the author from the wave-lengths of the lines in the germanium spectrum (Abstr., 1886, 768). The law of proportionality between the variations in the atomic weights of the elements, and the variations in the wave-lengths of the lines in their respective spectra, thus receives further confirmation.resembles the sesquisulphide. w. c. w. C . H. B. Gold Oxides. By G. K R ~ S S (Bey., 19, 2541--9549).-Aurons oxide, Au20, could not be obtained in the pure state by any of the known methods. It is prepared by treating the double bromide of gold with aqueous sulphurous acid at 0" until the intense red colour of the bromide has disappeared. The colourless solution of aurous bromide so formed is warmed with potash, which causes a separation of aurous hydroxide. The oxide is dark violet when moist, greyish- violet when dry ; when freshly precipitated, it dissolves in cold mater, yielding an indigo-coloured solution with a brownish fluorescence ; it is insoluble in hot water.The solution has a characteristic absorp- tion spectrum showing a band at X = 587.0. Hydrochloric and hydrobromic acids convert it into gold and the corresponding auric compounds ; other acids have no action. The hydroxide parts with water at 200", and at 2.50" gives up its oxygen. Aurosoauric oxide, Autoz (compare Schottlander, Abstr., 1883,853),16 ABSTRACTS OF C€€EMICAL PAPERS. 70". -- 81-0 31'0 12.0 - is prepared by gradually heating pure auric hydroxide up to 160" until the weight remains constant. It is a fine dark yellowish- brown powder, is very hygroscopic, and can only be kept over phosphoric anhydride. When heated above 173", it gives off oxygen. Auric oxide, AuZ03, is conveniently obtained by treating auroauric chloride (1 part) with water (50 part's), boiling the solution, and adding finely powdered magnesia nlba, stirring the whole time, until the red colour of the auric chloride has disappeared.The gold trihydroxide is filtered, mixed with water (20 parts), treated with nitric acid, sp. gr. 1.4 (10 parts), and left for 24 hours. The residue, after filtering, is mixed with an equal amount of water and nitric acid, and heated for six hours at 100". The undissolved portion is now free from magnesia, and is washed with water to remove nitric acid. The pure auric hydroxide has a yellowish-brown colour when moist, and is rather readily soluble in nitric acid. When kept for weeks over phosphoric anhydride, it is converted into aurylic hydroxide, AuO*OH, and when carefully heated yields auric oxide.The so-called " purple oxide of gold " appears to be gold in a finely divided state. The author was unable to obtain Prat's gold siiperoxide and Figuier's auric acid (Compt. rend., 70, 844), or any other oxide of gold than the three described. This behaviour of gold is in accord- ance with the position (between platinum and mercury) assigned to it in the periodic arrangement of the elements. Solubility of some Gold Compounds. By T. ROSEKBLADT (Bw., 19, 2535--2538).-The following table shows the amounts of the anhydrous double salts contained i n 100 pnpts by weight of aqueous solution at the given temperatures :- N. H. M. 80". - I 85.7 35.3 16.3 -- 1 10". 60.2 57'7 38.2 9.0 0 - 8 NaAuC1, LiduC4 RbAuC1, KAuC14 CsAuCl4 64.0 62.5 48-7 13.4 1.7 69.4 67.3 59'2 17'2 3.2 20".1 30". 7'7-5 72.0 70.0 22.2 5.4 1 40". 1 50". 58 '2 53 -1 27 -7 4 . 6 0 . 5 60". 90 *o 76 -4 80 *2 26 -6 8 - 2 90". - 39 -7 21 -7 looo. - 44.2 2'7 -5 ~~~~ ~ ~ ~ ~~~~~~~~~~~ The solubilities of the double salts (with exception of the lithium salt) are inversely proportional to the molecular weights of the salts. N. EL. M.INORGAXIC CHEMISTRY.I n or g a n i c C h e m i s t r y .11Conversion of Calcium Hypochlorite into CalciumChlorafe. By G. LUNGE (J. SOC. Chem. h d , 4, 722--724).-1t hasalready been shown by the author that the reaction 6Ca0C12 =5CaC12 + Ca(C10& does not take place completely and withoutconsiderable loss of oxygen, except in presence of an excess ofchlorine, idthough that chlorine does not appear in the equation.Theauthor’s experiments point to the following conclusions :-The mos13: ABSTRAOTS OF CHEMICAL PAPERS.favourable way of converting hypochlorite into chlorate is t o raise thetemperature of the solution, and simultaneously have an excess ofchlorine present therein. A large excess of chlorine is useless,perhaps i-sjurions, for the yield of chlorate. On the large scale, it isnot necessary to raise the temperature by artificial means, the heatproduced by the reaction being sufficient to complete it. The con-version at the ordinary temperature proceeds almost at once to thelimit of about 70 per cent., but subsequently makes very slow pro-gress, so that it is impracticable to wait for its completion withoutheating. D. B.A Crystalline Silico-carbonate from Soda Liquors.By C.RAMMELSBERG (CYhem. Id., 9, 110-11 l).-Two specimens of crystalsremoved from the pump of a carbonating tower at the " Hermannia "Chemical Works at Schonebeck had the following composition :-COz. Si02. AlZO3. CaO. Na,O. HzO.I. 22.75 14-99 7.38 13.28 22-37 19.23 = 10011. 21.50 15-00 8.03 12.41 21.66 21.40 = 100Allowing for adhering soda liquor, these numbers lead to theformula Na18Ca6A12(Si,C)210R3 + 3oH20, or the substance is a, com-pound of the isomorphous normal carbonates and silicates3 [3Nh( Si, C) 0,,2Ca (Si, C) Oy ],2A1( Si, C),O,,.The crystals are rhombic, exhibiting the form of the primarypyramid with its acuter terminal edges truncated, or frequently atabular form due to the development of the end face ; the ratio of theaxes is 0.5295 : 1 : 1.73.These crystals were first observed in 1880, but the specimen thenanalysed contained an admixture of gay-lussite, and the silica andalumina were not recognised as essential constituents.X. J. $.Sodium-calcium Carbonates from the Soda, Manufacture.By C. REIDEMEISTER (Chem. Ind., 9, lll).-In the Chemische Iyadustriefor 1884 the author described the rhornbic crystals analysed by Ram-melsberg (see preceding Abstract) as a hydrated sodium calciumcarbonate. They are now found to occur in both the crude and car-bonated liquors. In the former, in which formerly only gay-lussitehad been recognised, they have now been observed with crystals ofgay-lussite deposited on their surfaces. The gay-lussite crystals arechiefly deposited from liquors in process of cooling; the silico-carbonate from those undergoing slow evaporation.M. J. S.Double Nitrites of Caesium and of Rubidium. By T. ROSEN-BLADT (Bey., 19, 2531-2535).-The double nitrite of cesium andeobalt, ~CSNO,CO(NO~)~ + H20! is formed by boiling equal partsof cvbztlt nitrate and sodium acetate in water (15 parts), filter-ing, and adding to the cold solution first acetic acid (20 parts),and then a, strong solution of sodium nitrite until tho liquid has anorange cdour, it irs then filtered, and treated with a solution of INORGANIC OHEMISTRT. 13eaesium salt. The double salt 3RbN02,Co(N02), + HzO is preparedin a similar manner. They are both lemon-coloured crystalline salts,and resemble in their behaviour Fischer's potassium-compound, exceptin their solubility in water, the czesium salt dissolving only in20,100 parts of water at 17", and the rubidium salt in 19,800 parts ofwater.The method employed in analysing these compounds isdescribed.Thallium also yields a double salt with cobalt nitrite ; it is a redcrystaliine compohd, soluble in 23,810 pai.ts of water..N. H. M.Decomposition of Glass by Carbonic Anhydride condensedon its Surface. By R. BUNSEN (Ann. Phys. Chem. [2], 29, 161-165) .-Formerly the author attributed the absorption of carbonicanhydride by glass-wool rather to an interpenetration of the glass bythe molecules of the liquefied gas rather than to any chemical change(Abutr., 1884, 146). This view would also be confirmed by the obser-vations on the stability of glass towards the most concentrated hydro-chloric acid.However, if the glass-wool be damp, whereby theabsorption of the gas is remarkably increased (Abstr., 1885, 867),the possibility of a chemical change is not precluded. Accordinglythe glass (49.453 grams) used in the experiment was exhausted withwater, and a residue obtained from it corresponding to the decompo-sition of 2.882 grams of glass, or 5-83 per cent. of the whole.Even if the chemical change consists in the production at first ofsodium carbonate, which would take up a further quantity of carbonicanhydride, corresponding with the formation of sodium hydrogencarbonate, which on subsequent heating would again be driven off, yetall the carbonic anhydride absorbed caunot be accounted for in thisway.The phenomenon is thus not only one of chemical change, butalso of absorption, the particular degree of each of which cannot beestimated.If, then, carbonic acid can decompose glass, the same is to beexpected of water. Observations in the course of experiments on thedetermination of the tension of aqueous vepour at high temperaturesare quoted to show that glass tubes containing water-vapour whenheated at 88" are converted into n white porcelain-like mass, and thattheir inner diameter is diminished by one-tenth.Note.-On the decomposition of glass by carbonic anhydride underhigh pressures compare Pfaundler (Abstr., 1885, 868).Purification O f Yttria. By L. DE BOISBAUDRAN (Compt.rend., 103,627-629).-A comparatively very pure sample of yttria was sub-jected to 32 series of fractionations by means of ammonia. Theproduct of the last precipitation of the thirty-second series showed8 less brilliant fluorescence than the original earth, and the bands ofZa and 2/3 in the spectrum had diminished considerably in intensity,whilst the bands of samarium retained their original vigour. Thecolour of the fluorescence had changed from y ellowish-green toorange- yellow.This last precipitate was submitted to 26 series of fractionationsby meam of oxalic acid. The brilliancy of the fluorescence continu-V. H. V.V. H. V14 ABSTRACTS OF CHEMICAL PAPERS.ally diminished, but, contrary to the phenomena observed during thefirst fractionation, the samarium bands diminished in intensity muchmore rapidly than the bands of Za and ZP.The earth from the oxalateprecipitated at the end of the fifth fractionation showed very faintlythe citron band and the double green band of Za and ZP, with a traceof the red bands of samarium. The oxalate from the twenty-sixthfractionation yielded a very white earth which showed a trace of thecitron band of Za, but none of the red, green, blue, and violet bands inthe spectrum described by Crookes. This yttria gave no fluorescencewhen mixed with lime, but its hydrochloric acid solution gave abrilliant spark spectrum of yttrium.The sulphate prepared from the last precipitate f ~ o m the fractiona-tion with oxalic acid gave a rose-coloured fluorescence due to thepresence of a trace of bismuth.Heating and Cooling of Cast Steel.By OSMOND (Compt. rend.,103, 743-746) .-The phenomena which accompany the heating andcooling of cast steel were investigated by means of a thcrmo-electric couple connected with an aperiodic galvanometer.Barrett observed that when a bar of hard iron is cooled from awhite heat there is a sudden development of heat at dull redness, andthe magnetic properties of the iron change abruptly. He distin-guished this phenomenon by the name recalescence. Chatelier andYinchon found that at about 700" a molecular modification of pureiron is formed.The author's experiments show that as the proportion of carbonincreases from 0.16 to 1-25 per cent. the temperature at which themolecular alteration takes place falls, whilst the point of recalescencerises, until in hard steel the t v o points coincide.The rate at whichheating takes place has no influence on the temperature at which thetwo changes take place, but these temperatures are affected by the rateof cooling, and are lower the greater the rapidity with which coolingtakes place. In quick tempering, no such phenomena are observed ;the heat corresponding with the non-effected changes remains in theiron. The two critical points also fall somewhat if the initial tem-perature of heating is raised. During annealing after tempering, thelatent heat of tempering is liberated gradually and not abruptly.By T. KNIESCHE (Chenz. Zeit., 10, 1067--1068).-1ntreating tungsten ores, sodium tungstate is first obtained, then from thistungstic acid, which i n its turn is reduced at a temperature of 1600"to metallic tungsten.The preparation of the chemically pure metalis simply a question of time; any way, as obtained at present, it isuseful in steel making. It must be added only when the irou is in itperfectly fluid state. Sodium tungstate is used for rendering inflam-mable materials fireproof.C. H. B.C. H. R.Tungsten.D. A. L.Titanium. By 0. v. PFORDTEN (AnnuZen, 234, 257--299).-Thesulphides of those metals which have a strong affinity for oxygencannot be obtained in the pure date by passing carbon bisulphideover the metallic oxides at a red heat, but they can be prepared by thINORGANIC CEEMISTRY.15action of pure sulphuretted hydrogen on the metallic chlorides. Thegas must be passed through chromons chloride to remove traces ofoxygen, and is then dried by means of phosphoric oxide. The authordisputes Thorpe's statement (Trans., 1885, 492) that sulphurettedhydrogen can be dried by passing thegas through sulphuric acid. Atthe ordinary temperature, sulphure tted hydrogen reduces titanicchloride to titanous chloride ; at a higher temperature, a compoundis precipitated, which is probably a sulphochloride. Crystals oftitanium disulphide, TiS2, are deposited when sulphuretted hydro-gen and the vapour of titanium tetrachloride are passed througha red-hot tube from which atmospheric air has been carefullyexpelled. The bisulphide is not attacked by hydrogen at a red heatin the presence of an excess of sulphuretted hydrogen.A t a redheat, it is oxidised completely by carbonic anhydride, and it splits upinto the sesquisulphide, Ti2&, and sulphur in an atmosphere of hydro-gen or nitrogen. The sequisulphide is a metallic grey substance,insoluble in sodium hydroxide solution; it dissolves in nitric andstrong sulphuric acids with a green coloration. The author is of opinionthat the sesquisulphide described by Thorpe (Zoc. cit.) is an impureRubstance, and that its green colour is due to the presence ofvanadium.The sesquisulphide is reduced to monosulphide by hydrogen a t ahigher temperature than that at which refractory glass softens. Thecrystals of the monosulphide are dark red.Dilute nitric acid attacksthe monosulphide with difficulty ; in other respects, this substanceAtomic Weight of Germanium. By L. DE BOISBAUDRAN (Corn@.rend., 103, 452--453).-Winkler's recent determination of the atomicweight of germanium, 72.32 (hbstr., 1886, 985), agrees perfectly withthe value calculated by the author from the wave-lengths of thelines in the germanium spectrum (Abstr., 1886, 768). The law ofproportionality between the variations in the atomic weights of theelements, and the variations in the wave-lengths of the lines in theirrespective spectra, thus receives further confirmation.resembles the sesquisulphide. w. c. w.C . H. B.Gold Oxides. By G. K R ~ S S (Bey., 19, 2541--9549).-Auronsoxide, Au20, could not be obtained in the pure state by any of theknown methods.It is prepared by treating the double bromide ofgold with aqueous sulphurous acid at 0" until the intense red colourof the bromide has disappeared. The colourless solution of aurousbromide so formed is warmed with potash, which causes a separation ofaurous hydroxide. The oxide is dark violet when moist, greyish-violet when dry ; when freshly precipitated, it dissolves in cold mater,yielding an indigo-coloured solution with a brownish fluorescence ; itis insoluble in hot water. The solution has a characteristic absorp-tion spectrum showing a band at X = 587.0. Hydrochloric andhydrobromic acids convert it into gold and the corresponding auriccompounds ; other acids have no action. The hydroxide parts withwater at 200", and at 2.50" gives up its oxygen.Aurosoauric oxide, Autoz (compare Schottlander, Abstr., 1883,853)16 ABSTRACTS OF C€€EMICAL PAPERS.70".--81-031'012.0-is prepared by gradually heating pure auric hydroxide up to 160"until the weight remains constant. It is a fine dark yellowish-brown powder, is very hygroscopic, and can only be kept overphosphoric anhydride. When heated above 173", it gives off oxygen.Auric oxide, AuZ03, is conveniently obtained by treating auroauricchloride (1 part) with water (50 part's), boiling the solution, andadding finely powdered magnesia nlba, stirring the whole time, untilthe red colour of the auric chloride has disappeared. The goldtrihydroxide is filtered, mixed with water (20 parts), treatedwith nitric acid, sp. gr. 1.4 (10 parts), and left for 24 hours. Theresidue, after filtering, is mixed with an equal amount of water andnitric acid, and heated for six hours at 100". The undissolvedportion is now free from magnesia, and is washed with water toremove nitric acid. The pure auric hydroxide has a yellowish-browncolour when moist, and is rather readily soluble in nitric acid. Whenkept for weeks over phosphoric anhydride, it is converted into aurylichydroxide, AuO*OH, and when carefully heated yields auric oxide.The so-called " purple oxide of gold " appears to be gold in a finelydivided state.The author was unable to obtain Prat's gold siiperoxide andFiguier's auric acid (Compt. rend., 70, 844), or any other oxide ofgold than the three described. This behaviour of gold is in accord-ance with the position (between platinum and mercury) assigned toit in the periodic arrangement of the elements.Solubility of some Gold Compounds. By T. ROSEKBLADT (Bw.,19, 2535--2538).-The following table shows the amounts of theanhydrous double salts contained i n 100 pnpts by weight of aqueoussolution at the given temperatures :-N. H. M.80".- I85.735.316.3--1 10".60.257'738.29.00 - 8NaAuC1,LiduC4RbAuC1,KAuC14CsAuCl464.062.548-713.41.769.467.359'217'23.220". 1 30".7'7-572.070.022.25.4140". 1 50".58 '253 -127 -74 . 60 . 560".90 *o76 -480 *226 -68 - 290".-39 -721 -7looo.-44.22'7 -5~~~~ ~ ~ ~ ~~~~~~~~~~~The solubilities of the double salts (with exception of the lithiumsalt) are inversely proportional to the molecular weights of the salts.N. EL. M