106 ABSTRACTS OF CElEMIOAL PAPERS. In o r g a n i c C h e mi s t r y. Hydrogen Peroxide. By G. TANMANN (Zeit. physikal. Chem., 4, 441-443) .-The spontaneous decomposition of hydrogen peroxide in alkaline solution is found to be independent of the amount or nature of the base which is present. It appears probable from the author's experiments that it is really caused by the presence of traces of metallic oxides, such as the oxide of iron, dissolved in the alkali. It is shown that the addition of small quantities of such oxides in- creases enormously the rate of decomposition. The freezing points of aqueous solutions of hydrogen peroxide were determined, and from these a molecular reduction of 8-79 was found. Hydrogen peroxide being a, non-electrolyte, this number would correspond with the formula H404.[3 3, 1, 695--699).-A review of the known hydrochlorides of chlorides, and a discussion of their probable constitution. H. C. Hydrochlorides of Chlorides. By R. ENGEL (BUZZ. SOC. Chim. T. G. N. Iodic Acid. By H. LESCEUR (BiiZZ. SOC. Chim. [3], 1, 563).-The crystals of iodic acid deposited from its solution in dilute or moderately concentrated nitric acid are monohydrated, TV hereas those obtained from the solution of iodic acid in concentrated nitric acidINORQANIO CHEMISTRY. 107 are anhydrous. The author thinks that the crystals deposited from solution in nitric acid of intermediate strength are mixtures of the hydrated and anhydrous varieties. Iodic Acid; Double Salts of Iodic Acid with other Acids. B.y C. W. RLOMSTRAND ( J .p r . Chem. [g], 40, 305-340 ; compare Abstr., 1887, 337) .-In the oxygen-acids of phosphorus and iodine only one atom of oxygen is strongly united to the phosphorus and iodine, the radicles being PO-0 and 10.0 respectively, thus differing from the oxygen-acids of nitrogen, chlorine, and bromine, where two atoms of oxygen are equally strongly united to the nitrogen, chlorine, or bromine, the radicIes being NO,, C102, and BrO, respectively. I n support of the above statement, the author has prepared double salts of iodic acid with other acids which may be regarded as conden- sation-products, requiring for their formation an extra-radicle oxygen atom, analogous to that which is allowed to exist in aldehyde and to be the cause of the easy polymerisation of that substance; thus, C,H,:O + O:C,H, = C2H,:O2:CzB4.The formula for iodic acid thus becomes HO-IO:O. Potassium sulphatoiodate was obtained by mixing potassium pyro- sulphate (1 mol.) and iodate (If mol.) in concentrated solution, and its formula found to be identical with that of Marignac's salt KO-1 O(OH)*O*SO,*OK. Potussium molybdoiodate, KO*IO(OH)*O~MoO,~OH + H,O, is ob- tained as a white precipitate on adding a concentrated solution of potassium nitrate to a solution of sodium molybdate and iodic acid in nitric acid ; it crystallises with disculty in short needles, and is sparingly soluble in water. Ammonium moly bdoiodate is obtained in the same way, and has similar properties, but contains no water of crystallisation. The thallium and lead salts were obtained.Molybdo- iodic acid is obtained as a yellowish, transparent mass on evaporating the solution formed by the action of dilute sulphuric acid on a mixture of barium iodate and molybdate. Several of its reactions with in- organic and organic salts are given. Potassium tungstoiodate, KO. WO,.O-IO(OH)OK + H20, is obtained by adding, by degrees, a solution of iodic acid to one of potassium tungstate ; after some hours, a crystalline magma is obtained, more than 90 per cent. of which consists of slender needles of the tungsto- iodate, the rest being tabular crystals of acid tungstate. Potassium chromoiodate bas been described by Berg (Abstr., 1887, 776) ; the author's analyses of this salt leave some doubt both as to the amount of water it contains and as to its formula.T. G. N. The author has also obtained an ammoniwm triiodate, NH,O*IO( OH).O.IO( OH)*O*IO,, of which the crystallography is given, and a sodium triiodate, N a ~ * I O ( O H ) ~ O ~ I ~ ~ O ~ ) * O ~ I ~ ~ + +H,O. Specific Gravity of Ammonia Solutions. By G. LUNGE and T. WIERNIK (Zeit. m g . Chem., 1889, 181--183).-The authors have redetermined with extreme care the sp. gr., referred to water a t 15", percentage of ammonia, and coefficient of expansion of ammonia A. G. B.108 ABSTRACTS O F CHEMICAL PAPERS. solutions of 24 different strengths. their table :- The following is an abstract of I--- --- 0 -990 0.980 0 -970 0.960 0 *950 0 *940 2 -31 4 30 7 -31 9 -91 12 -72 15 *63 Correction of t,he sp. gr. for f lo. Specific gravity at 15". 0 -00020 0 -00023 0 -00025 0 *00029 0 *00034 0 -00039 0 '930 0 -920 0 910 0 *goo 0 *890 0 -880 Percentage of NH? -- 1.8 -64 21 *75 24 *99 28 *33 31 *75 35 -60 Correction of t.he ep.gr. for f lo. --- 0 *00042 0 -00047 0 *00052 0 -00057 0 -00061 - M. J. S. A Derivative of Boric and Phosphoric Acids. By G. MEYER (Ber., 22, 2919).-When a mixture of boric and phosphoric acids is heated to redness, a very inert, white substance, P04B, is formed. It reddens moist litmus paper, but seems not to be dissolved by boiling water, and only to be very slowly attacked by boiling aqueous alkalis. Fusion with alkalis or alkaline carbonates causes instant decomposition, and fusioE with sodium chloride also yields a soluble inel t . L. T. T. By E. P. HARRIS (Ckem. Cent., 1889, ii, 283-284) .-The author has successf idly prepared silicon by means of Gatterman's method, ignition of fine sand with magnesium powder, and in addition to the already known halogen-derivatives, he has prepared a &con nitride, NH2*SiN, by acting on silicon chloride or silicon iodide with dry ammonia, whereby a considerable development of heat takes place.If the flux, obtained in the pre- paration of the silicon, be treated with dilute hydrochloric acid to dissolve out the magnesium oxide. silicon chloroform is obtained Silicon. It is a snow-white powder. u as a light, colourless, inflammable liquid, boiling a t 42-44". J. W. L. Preparation of the Chlorides of Silicon, Aluminium, &c. By H. N. WARREN (Chem. News, 60, 158).-Iron alloys of silicon or aluminium are heated to redness in a clay crucible and a current of chlorine gas is passed into the mass, suitable means being adopted to collect the volatile products. With chlorine and silicon-iron, the ferric chloride is condensed first, then the silicon chloride ; if hydrogen chloride is used instead of chlorine, the ferrous chloride formed re- mains in the crucible and silicon chloroform distils off.The aluminium chloride obtained from aluminium-iron is purified by mixing with iron borings and distilling, or if the aluminium-iron alloy is mixed with common salt previous to submitting it to the action of chlorine, a sublimate of aluminium sodium chloride is obtained. D. A. L. Combining Energy of Rubidium. By N. BEKETOFF (Chew.. Centr., 1889, ii, 245, from Bull. Acad., St. Pe'tsrsbourg [2], 1, 117-118).-Preparation of the metal.-Rubidium hydroxide is precipitated fromINORQANIC GHEMl STRY. 109 the sulphate by barium hydroxide, calcined in a silver dish, and heated with fine aluminium clippings in an iron cylinder in a furnace ; the cylinder being connected with a glass tube by means of an iron tube. A mixture of 1 equivalent of rubidium hydroxide and 1: equiva- lents of aluminium gives the best results. From 113 grams of hydroxide and 31 grams of aluminium, 31 grams of very pure rubidium was obtained. J. W. L. Potassium Plumbate. Crystalline Hydrated Thallic Oxide. By D. CARNEGIE (Chern. News, 60, 113).-Potassium plumbate is formed when potassium plumbite, obtained by dissolving litharge in molten potash, is strongly heated, with free access of air, for some time.The colourless aqueous solution has strongly oxidising pro- perties ; it evolves chlorine with excess of dilute hydrochloric acid or with dilute sulphuric acid when the latter is added rapidly in excess, lead sulphate being also formed, the chlorine in this case being derived from the potassium chloride present as an impurity in the potash ; when boiled with litharge, it yields lead peroxide and potassium plumbite ; whilst with mnnganous sulphate it gives hydrated man- ganic oxide, and dilute sulphuric acid added slowly produces a brown precipitate of hydrated lead peroxide, Pb02,H20. Fused potash dissolves small quantities of thallic oxide, and the resulting yellow mass when treated with water yields a reddish- brown precipitate of the hydrated thallic oxide.If, however, the fusion is continued for some time, a mass of very light, glistening, microscopic, hexagonal plates is produced, of the composition T1,0,,3H20; they are brown in colour but transmit yellow light. They are unaffected by a temperatnre of 340", and are readily soluble in dilute hydrochloric and sulphuric acids, but generally a slight reduction to thalloas salt takes place. D. A. L. Influence of Hydrogen Chloride on the Solubility of Cuprous Chloride and of Lead Chloride. By R. ENGEL (Bull. SOC. C'hi?~., [3], 1, 693--695).-The amount of cuprous chloride dissolved bv hydrochloric acid increases with the hydrogen chlor ide present. A saturated solution of cuprous chloride in hydrochloric acid when cooled to -40" deposits cuprons chloride crystals, no hydrochloride of cuprous chloride being formed.The presence of hydrogen chloride a t first determines a diminished solubility of lead chloride, and it is not until a considerable amount of hydrogen chloride is present that an increasing solubility obtains ; this the author thinks is due to tbe formation of the soluble hydro- chloride of lead chloride. Solubility tables for each of the above salts in hydrochloric acid of various strengths are given. Oxysulphides of Mercury. By T. POLECK (Ber., 22,2859-2861 ; compare Poleck and Goercki, Abstr., 1888, 1166j.--The anthop's further experiments have shown that the oxysulphides of mercury are not known, and that their existence is highly improbable. T. G. N. I!'. S. K.110 ABSTRAOTS OF CHEMICAL PAPERS. Aluminium Amalgam and its use in Thermochemistry.By J. B. BAILLE and C. FERY (Ann. Chim. Phys. [S], 17, 246-256).- Aluminium amalgam was first described by one of the authors iu 1875. Experiments in sealed tubes in an atmosphere of indifferent gas show that solution of aluminium by mercury proceeds more rapidly the higher the temperature, and i~ especially active a t the boiling point of mercury. It is, however, the liqnid metal and not its vaponr which attacks the aluminium. The quantity of aluminium dissolved a t first increases with the time, but attains a maximum at the end of about two hours ; it is independent of the pressure inside the tube and of the extent of metallic surface ia contact, but is pro- portional to the quantity of mercury present. When the mercury cools, crystals of the amalgam separate as a thick paste on the surface ; it has the composition A1,Hg3.In moist air it rapidly oxidises with formation of the hydroxide, Al?O(OH),. It decomposes water at the ordinary temperature, the change being especially rapid with very thin sheets of aluminium amalgamated on the surface. T t is attacked by nit& acid, which has no action on aluminium alone, and rapidly decomposes a solution of potassium hydroxide with evolution of hydrogen. If aluminium amalgam is mixed with antimony amalgam, metallic antimony separates at the surface in small crystals, and after a time the aluminium oxidises, so that the mercury is obtained free from both metals. When, on the other hand, lead amalgam is added to the aluminium amalgam, the aluminium separates at the surface and is rapidly oxidised.This phenomenon is analogous to the expulsion of aluminium from its alloys with copper, tin, &c., by mixing the fused alloys with lead. The action of moist air on amalgamated aluminium foil in the calorimeter was utilised for the determination of the heat of forma- tion of aluminium oxide and the hydroxides. The results obtained were as follows :-Al2O3? 392.6 Cals. ; Al2O(0H),, 394.6 Cals. ; A12(0H),, 395.6 Gals. The formation of the aluminium amalgam and the displacement of the aluminium by lead are accompanied by no appreciable thermal disturbance. C. H. B. Preparation of Manganese from Manganese Chloride and Magnesium. By E. GLATZEL (Ber., 22, 2857-2859).-Manganese can be prepared by heating a mixture of finely divided, anhydrous manganese chloride (1 00 gmms) and dry, powdered potassium chloride (200 grams) in a covered Hessian crucible until it just melts, and then adding magnesium (15 grams) in portions of 3-4 grams, a t intervals of 2-3 minutes; if the fused mass is too hot a very violent reaction occurs, and the contents of the crucible are thrown out.The crucible is covered again, heated more strongly, and then allowed to cool slowly i n the furnace. The yield of manga- nese is 20-25 grams, the metal containing traces only of silica, and being quite free from magnesium. The specific gravity of manganese, as the average of four determi- nations, was found to be 7.3921 at 22". F. S . K.MINERALOGICAL CHEMISTRT. 11 t Reduction of Ferric Bromide by Boiling.By L. L. DE KONINCK (Zeit. ang. Chsm., 1889, 149) .-A solution of ferric bromide containing excess of bromine begins to show the presence of a ferrous salt as soon as the excess of bromine has been expelled by boiling. Ferric bromide, free from bromine and from ferrous salt, can only be obtained by passing air through the solution in the cold. The excess of bromine is very tenaciously retained. M. J. S.106 ABSTRACTS OF CElEMIOAL PAPERS.In o r g a n i c C h e mi s t r y.Hydrogen Peroxide. By G. TANMANN (Zeit. physikal. Chem., 4,441-443) .-The spontaneous decomposition of hydrogen peroxide inalkaline solution is found to be independent of the amount or natureof the base which is present. It appears probable from the author'sexperiments that it is really caused by the presence of traces ofmetallic oxides, such as the oxide of iron, dissolved in the alkali.Itis shown that the addition of small quantities of such oxides in-creases enormously the rate of decomposition.The freezing points of aqueous solutions of hydrogen peroxidewere determined, and from these a molecular reduction of 8-79 wasfound. Hydrogen peroxide being a, non-electrolyte, this numberwould correspond with the formula H404.[3 3, 1, 695--699).-A review of the known hydrochlorides of chlorides,and a discussion of their probable constitution.H. C.Hydrochlorides of Chlorides. By R. ENGEL (BUZZ. SOC. Chim.T. G. N.Iodic Acid. By H. LESCEUR (BiiZZ. SOC. Chim. [3], 1, 563).-Thecrystals of iodic acid deposited from its solution in dilute ormoderately concentrated nitric acid are monohydrated, TV hereas thoseobtained from the solution of iodic acid in concentrated nitric aciINORQANIO CHEMISTRY. 107are anhydrous.The author thinks that the crystals deposited fromsolution in nitric acid of intermediate strength are mixtures of thehydrated and anhydrous varieties.Iodic Acid; Double Salts of Iodic Acid with other Acids.B.y C. W. RLOMSTRAND ( J . p r . Chem. [g], 40, 305-340 ; compareAbstr., 1887, 337) .-In the oxygen-acids of phosphorus and iodineonly one atom of oxygen is strongly united to the phosphorus andiodine, the radicles being PO-0 and 10.0 respectively, thus differingfrom the oxygen-acids of nitrogen, chlorine, and bromine, where twoatoms of oxygen are equally strongly united to the nitrogen, chlorine,or bromine, the radicIes being NO,, C102, and BrO, respectively.I n support of the above statement, the author has prepared doublesalts of iodic acid with other acids which may be regarded as conden-sation-products, requiring for their formation an extra-radicle oxygenatom, analogous to that which is allowed to exist in aldehyde and tobe the cause of the easy polymerisation of that substance; thus,C,H,:O + O:C,H, = C2H,:O2:CzB4. The formula for iodic acid thusbecomes HO-IO:O.Potassium sulphatoiodate was obtained by mixing potassium pyro-sulphate (1 mol.) and iodate (If mol.) in concentrated solution, andits formula found to be identical with that of Marignac's saltKO-1 O(OH)*O*SO,*OK.Potussium molybdoiodate, KO*IO(OH)*O~MoO,~OH + H,O, is ob-tained as a white precipitate on adding a concentrated solution ofpotassium nitrate to a solution of sodium molybdate and iodic acidin nitric acid ; it crystallises with disculty in short needles, and issparingly soluble in water.Ammonium moly bdoiodate is obtained inthe same way, and has similar properties, but contains no water ofcrystallisation. The thallium and lead salts were obtained. Molybdo-iodic acid is obtained as a yellowish, transparent mass on evaporatingthe solution formed by the action of dilute sulphuric acid on a mixtureof barium iodate and molybdate. Several of its reactions with in-organic and organic salts are given.Potassium tungstoiodate, KO.WO,.O-IO(OH)OK + H20, is obtainedby adding, by degrees, a solution of iodic acid to one of potassiumtungstate ; after some hours, a crystalline magma is obtained, morethan 90 per cent. of which consists of slender needles of the tungsto-iodate, the rest being tabular crystals of acid tungstate.Potassium chromoiodate bas been described by Berg (Abstr., 1887,776) ; the author's analyses of this salt leave some doubt both as tothe amount of water it contains and as to its formula.T. G. N.The author has also obtained an ammoniwm triiodate,NH,O*IO( OH).O.IO( OH)*O*IO,,of which the crystallography is given, and a sodium triiodate,N a ~ * I O ( O H ) ~ O ~ I ~ ~ O ~ ) * O ~ I ~ ~ + +H,O.Specific Gravity of Ammonia Solutions. By G. LUNGE andT.WIERNIK (Zeit. m g . Chem., 1889, 181--183).-The authors haveredetermined with extreme care the sp. gr., referred to water a t 15",percentage of ammonia, and coefficient of expansion of ammoniaA. G. B108 ABSTRACTS O F CHEMICAL PAPERS.solutions of 24 different strengths.their table :-The following is an abstract ofI--- ---0 -9900.9800 -9700.9600 *9500 *9402 -314 307 -319 -9112 -7215 *63Correctionof t,he sp. gr.for f lo.Specificgravityat 15".0 -000200 -000230 -000250 *000290 *000340 -000390 '9300 -9200 9100 *goo0 *8900 -880Percentageof NH?--1.8 -6421 *7524 *9928 *3331 *7535 -60Correctionof t.he ep. gr.for f lo.---0 *000420 -000470 *000520 -000570 -00061-M. J.S.A Derivative of Boric and Phosphoric Acids. By G. MEYER(Ber., 22, 2919).-When a mixture of boric and phosphoric acids isheated to redness, a very inert, white substance, P04B, is formed. Itreddens moist litmus paper, but seems not to be dissolved by boilingwater, and only to be very slowly attacked by boiling aqueousalkalis. Fusion with alkalis or alkaline carbonates causes instantdecomposition, and fusioE with sodium chloride also yields a solubleinel t . L. T. T.By E. P. HARRIS (Ckem. Cent., 1889, ii, 283-284) .-Theauthor has successf idly prepared silicon by means of Gatterman'smethod, ignition of fine sand with magnesium powder, and in additionto the already known halogen-derivatives, he has prepared a &connitride, NH2*SiN, by acting on silicon chloride or silicon iodide withdry ammonia, whereby a considerable development of heat takesplace.If the flux, obtained in the pre-paration of the silicon, be treated with dilute hydrochloric acid todissolve out the magnesium oxide. silicon chloroform is obtainedSilicon.It is a snow-white powder.u as a light, colourless, inflammable liquid, boiling a t 42-44".J. W. L.Preparation of the Chlorides of Silicon, Aluminium, &c.By H. N. WARREN (Chem. News, 60, 158).-Iron alloys of silicon oraluminium are heated to redness in a clay crucible and a current ofchlorine gas is passed into the mass, suitable means being adopted tocollect the volatile products. With chlorine and silicon-iron, theferric chloride is condensed first, then the silicon chloride ; if hydrogenchloride is used instead of chlorine, the ferrous chloride formed re-mains in the crucible and silicon chloroform distils off.The aluminiumchloride obtained from aluminium-iron is purified by mixing withiron borings and distilling, or if the aluminium-iron alloy is mixedwith common salt previous to submitting it to the action of chlorine,a sublimate of aluminium sodium chloride is obtained.D. A. L.Combining Energy of Rubidium. By N. BEKETOFF (Chew..Centr., 1889, ii, 245, from Bull. Acad., St. Pe'tsrsbourg [2], 1, 117-118).-Preparation of the metal.-Rubidium hydroxide is precipitated froINORQANIC GHEMl STRY. 109the sulphate by barium hydroxide, calcined in a silver dish, andheated with fine aluminium clippings in an iron cylinder in a furnace ;the cylinder being connected with a glass tube by means of an irontube.A mixture of 1 equivalent of rubidium hydroxide and 1: equiva-lents of aluminium gives the best results. From 113 grams ofhydroxide and 31 grams of aluminium, 31 grams of very purerubidium was obtained. J. W. L.Potassium Plumbate. Crystalline Hydrated Thallic Oxide.By D. CARNEGIE (Chern. News, 60, 113).-Potassium plumbate isformed when potassium plumbite, obtained by dissolving litharge inmolten potash, is strongly heated, with free access of air, for sometime. The colourless aqueous solution has strongly oxidising pro-perties ; it evolves chlorine with excess of dilute hydrochloric acid orwith dilute sulphuric acid when the latter is added rapidly in excess,lead sulphate being also formed, the chlorine in this case being derivedfrom the potassium chloride present as an impurity in the potash ;when boiled with litharge, it yields lead peroxide and potassiumplumbite ; whilst with mnnganous sulphate it gives hydrated man-ganic oxide, and dilute sulphuric acid added slowly produces a brownprecipitate of hydrated lead peroxide, Pb02,H20.Fused potash dissolves small quantities of thallic oxide, and theresulting yellow mass when treated with water yields a reddish-brown precipitate of the hydrated thallic oxide.If, however,the fusion is continued for some time, a mass of very light, glistening,microscopic, hexagonal plates is produced, of the compositionT1,0,,3H20; they are brown in colour but transmit yellow light.They are unaffected by a temperatnre of 340", and are readily solublein dilute hydrochloric and sulphuric acids, but generally a slightreduction to thalloas salt takes place.D. A. L.Influence of Hydrogen Chloride on the Solubility of CuprousChloride and of Lead Chloride. By R. ENGEL (Bull. SOC. C'hi?~.,[3], 1, 693--695).-The amount of cuprous chloride dissolved bvhydrochloric acid increases with the hydrogen chlor ide present. Asaturated solution of cuprous chloride in hydrochloric acid whencooled to -40" deposits cuprons chloride crystals, no hydrochlorideof cuprous chloride being formed.The presence of hydrogen chloride a t first determines a diminishedsolubility of lead chloride, and it is not until a considerable amount ofhydrogen chloride is present that an increasing solubility obtains ;this the author thinks is due to tbe formation of the soluble hydro-chloride of lead chloride.Solubility tables for each of the above salts in hydrochloric acid ofvarious strengths are given.Oxysulphides of Mercury. By T.POLECK (Ber., 22,2859-2861 ;compare Poleck and Goercki, Abstr., 1888, 1166j.--The anthop'sfurther experiments have shown that the oxysulphides of mercuryare not known, and that their existence is highly improbable.T. G. N.I!'. S. K110 ABSTRAOTS OF CHEMICAL PAPERS.Aluminium Amalgam and its use in Thermochemistry. ByJ. B. BAILLE and C. FERY (Ann. Chim. Phys. [S], 17, 246-256).-Aluminium amalgam was first described by one of the authors iu1875. Experiments in sealed tubes in an atmosphere of indifferentgas show that solution of aluminium by mercury proceeds morerapidly the higher the temperature, and i~ especially active a t theboiling point of mercury.It is, however, the liqnid metal and notits vaponr which attacks the aluminium. The quantity of aluminiumdissolved a t first increases with the time, but attains a maximum atthe end of about two hours ; it is independent of the pressure insidethe tube and of the extent of metallic surface ia contact, but is pro-portional to the quantity of mercury present.When the mercury cools, crystals of the amalgam separate as athick paste on the surface ; it has the composition A1,Hg3. In moistair it rapidly oxidises with formation of the hydroxide, Al?O(OH),.It decomposes water at the ordinary temperature, the change beingespecially rapid with very thin sheets of aluminium amalgamated onthe surface.T t is attacked by nit& acid, which has no action onaluminium alone, and rapidly decomposes a solution of potassiumhydroxide with evolution of hydrogen.If aluminium amalgam is mixed with antimony amalgam, metallicantimony separates at the surface in small crystals, and after a timethe aluminium oxidises, so that the mercury is obtained free fromboth metals. When, on the other hand, lead amalgam is added tothe aluminium amalgam, the aluminium separates at the surface andis rapidly oxidised. This phenomenon is analogous to the expulsionof aluminium from its alloys with copper, tin, &c., by mixing thefused alloys with lead.The action of moist air on amalgamated aluminium foil in thecalorimeter was utilised for the determination of the heat of forma-tion of aluminium oxide and the hydroxides.The results obtainedwere as follows :-Al2O3? 392.6 Cals. ; Al2O(0H),, 394.6 Cals. ;A12(0H),, 395.6 Gals.The formation of the aluminium amalgam and the displacement ofthe aluminium by lead are accompanied by no appreciable thermaldisturbance. C. H. B.Preparation of Manganese from Manganese Chloride andMagnesium. By E. GLATZEL (Ber., 22, 2857-2859).-Manganesecan be prepared by heating a mixture of finely divided, anhydrousmanganese chloride (1 00 gmms) and dry, powdered potassiumchloride (200 grams) in a covered Hessian crucible until it justmelts, and then adding magnesium (15 grams) in portions of3-4 grams, a t intervals of 2-3 minutes; if the fused mass is toohot a very violent reaction occurs, and the contents of the crucibleare thrown out. The crucible is covered again, heated more strongly,and then allowed to cool slowly i n the furnace. The yield of manga-nese is 20-25 grams, the metal containing traces only of silica,and being quite free from magnesium.The specific gravity of manganese, as the average of four determi-nations, was found to be 7.3921 at 22". F. S . KMINERALOGICAL CHEMISTRT. 11 tReduction of Ferric Bromide by Boiling. By L. L. DEKONINCK (Zeit. ang. Chsm., 1889, 149) .-A solution of ferric bromidecontaining excess of bromine begins to show the presence of a ferroussalt as soon as the excess of bromine has been expelled by boiling.Ferric bromide, free from bromine and from ferrous salt, can onlybe obtained by passing air through the solution in the cold. Theexcess of bromine is very tenaciously retained. M. J. S