106 ABSTRACTS OF CHEMICAL PAPERS. T e c h n i c a l C h e m i s t r y . Oxalate Developer for Gelatin Plates. By H. W. LORD (Chew, Cmtr., 1885, 668).-10 grams of sodium sulphite are dis- solved in 175 C.C. of a concentrated solution of potassium oxalate and 50 C.C. of a concentrated solution of ferrous sulphate added. About 1 C.C. sulphuric acid is then dropped in, until the mixture smells of sulphurous acid. This forms a very energetic developer, and the same quantity may be used several times. L. T. T. New Photographic Copying Paper. By H. J. SHAWCROSS (Chenz. Ceiztr., 1885, 668) .-The author covers the prepared paper with the powdered solid developer (tnnnic acid or other compound giving coloured precipitates with ferric but none with ferrous salts), which is well rubbed in.After exposure under the drawing to be copied the paper is laid in water, and the excess of developer removed with the aid of a sponge. A separate developing bath is thus avoided. L. T. T. Electric Aecumulators. By S. SCHENEK and S. FARBAKY (Dingl. polyt. J., 257, 357-369 and 458465).-1n 1883 the Academy of Mining and Forestry in Schemnitz, Hungary was furnished with incandescent lamps, the electric current being supplied by about 90 accumulators. The present paper describes the construction of the accnmulators employed, and gives an account of some observa- tions made by the authors. To study the behaviour of the sulphuricTECHNICAL CHEMISTRY. 107 acid during the condensation and the discharge of the current, a series of experiments was made. It was found that when the accumulators are charged the sulphates are decomposed, sulphuric acid being liberated, whilst on discharging, the sulphates are again formed, the free acid being recombined.To determine the, ratio of accrnmulated energy to acid set free, and the ratio of dis- charged energy to acid fixed, a further series of trials had to be made. The results appear to show that when the acciimulators are charged, 2.23 grams of sulphuric acid are liberated per ampitre per hour, and that during their discharge 2.25 gmms of acid are fixed, giving a mean value of 2.24. The authors term this number the electro- chemical equivalent of sulphuric acid for an electric force of one amfire per hour. From this value, some useful data in regard to the preparation, treatment, and application of electric accumulators are said to be derived.Selenium Battery. By C. E. FRITTS (Diiigl. polyt. J., 258, 44). -The author in conjunction with Hopkinson has patented selenium cells of a certain construction, capable ot generating a current of electricity under the action of rays of light. A description of this battery is given in the original paper and more fully in Engineering, 39, 398 (see also this vol., p. 2). Gas Analyses. By F. FISCRER (Dirtgl. polyt. J. 258, 28).- Analyses of the gases from regenerative furnaces of the Hasse-Didier type and from pyrites kilns are given. Liquid Carbonic Anhydride. By H. HERBERTS (Chew,. Centr., 188.5, 543-5444 558-560, and 57d).-The author describes in detail the various methods at present employed f o r the manufacture of this product on the large male, as well as the objects and uses to which it may be applied.He has patented an apparatus and method for making the gas by the action of sodium bisnlphite ou a suitable carbonate, and also describes a process for obtaining it from alkaline bicarbonates. He proposes to employ liquid carbonic anhydride as a motive power where fuel is expensive. Further Experiments on the Decomposition of Ammonium Sulphate by Means of Sodium Sulphate. By G. BLATTNER (Dingl. polyt. J., 25 7, 4?4--479).-1n a previous communication (Abstr., 1885, 613), the author gave an account of some experi- ments made with the view of testing the correctness of Carey and Hurter’s reaction of obtaining ammonia from ammonium sulphate by decomposition with sodium sulphate, the sulphuric acid being utilised simultaneously.These experiments were made without the use of superheated steam, and it was found that from 1 5 t o 18 per cent, of the ammonia originally present in the ammonium sulphate employed was lost by decomposition. The object of the present investigation was to ascertain whether by the use of superheated steam it was possible to avoid the loss of ammonia or to reduce it to a minimum. The results showed that although the loss of ammonia was diminished (to from 1 to 3 per cent.), a large pro- D. B. D. B. I). B. J. K. C.I08 ABSTRACTS OF CHEMICAL PAPERS. portion remained in the residue, and sublimed in the form of hydrogen ammonium sulphate, only from SO t o 90 per cent. of the ammonia being liberated as such, The author considers that the success of this process on a large scale depends on the complete removal of these difEcul ties.D. B. Treating Celestin and Heavy Spar. By I?. KONTHER (Dingl. polyt. J., 258, 46).-Heavy spar, celestin, or gypsum is introduced into fused sodium or potassium chloride, when the impurities sink to the bottom. The fused mass is then drawn off, cooled, and lixiviated with water, the object being to obtain the sulphates in a finely divided state suitable for further chemical treatment (with sodium carbonate, ammonium carbonate, &c.). The resulting mass may be used also as a pigment for stucco-work, &c. Treating Raw Phosphates. By P. DIETRICH (DingZ. poZyt. J., 25 7 , 484) .-Crude phosphates containing calcium oxide or carbonate are treated with sdphurous anhydride to form gypsum, so that by the subsequent treatment with dilute acids only tlhe phosphate is attacked.To effect the complete conversion of the calcium oxide into gypsum, a mixture of air and sulphurous anhydride is allowed to act on the phosphate in the presence of superheated steam. D. B. D. B. Preparation of Alumina. By G. ROSENTHAL (Dingl. polyt. J., 257, 539) .-On evaporating a solution of aluminium sulphate and magnesium chloride, alumina, magnesium sulphnte, and hydrochloric acid are obtained. The residue is mixed with a small amount of caustic lime, and subjected to the action of superheated stea,m a t 300". After lixiviation, alumina mixed with ferric oxide remains. Owing to the higher specific gravity of the latter, its separation from the alumina may be effected by elutriation.D. B. Preparation of Chromic Acid. By W. A. ROWELL (Dingl. polyt. J., 258,47).-It is proposed to treat the solution of a chromate with a soluble stront'ium salt, a precipitate of strontium chromate being obtained. The filtrate, contaiiiing some strontium chromate in solution, is treated with barium chloride. The barium chromate thus formed is decomposed with hot dilute sulphuria acid in large excess. The mixture of dilute chromic and sulphuric acids having been separated from barium sulphate is treated hot with an amount of strontium chromate equivalent to the sulphuric acid present. This results in the formation of chromic acid. which is seDarated from the precipitate of strontium sulphnte and evaporated to dryness.D. B. Irregularities in the Composition of Steel Ingots. By P. ZETSCHE (Dingl. yoZyt. J., 258, 2l).--From an examination of the composition of different sections of steel ingots, the author infers that the metttlloids sulphur and phosphorus predominate in the inner parts of the castings, whilst silicon and manganese are found mainly in the outer portions, D, B.TECHNICAL CHEMISTRY. 109 Improvements in Metallurgy. (Dingl. polyk. J., 258, 31- 39.)-To work up tin scrap, Lambotte proposes subjecting the metal to the action of dilute gaseous chlorine a t a temperature exceeding the boiling point of chloride of tin. The rapours of stannic chloride evolved are condensed in chambers or passed into a solution of stannic chloride. For the production of an alloy of high conductivity Shaw mixes 100 parts of copper with 1 to 5 parts of aluminium, and adds 0.05 to 1 part of phosphorus.The aluminium previously mixed with palm oil is gradually stirred into the fused copper. The phosphorus is then introduced, and the mass poured into flat moulds. Guillemin prepares alloys of copper and cobalt of great' firmness and tenacity by fusing copper and cobalt with boric acid and charcoal. The tensile strengt,h of the resulting alloy amounted to 40 kilos. per square mm. It contained 48.3 per cent. of cobalt, 50.3 per cent. of copper, 1 per cent. of nickel, and 0.4 per cent. of iron. According to Crooke molten lead does not take up the silver, arsenic, and antimony from copper ores unless it is mixed intimately with the ore at a temperature below the fusing point of copper. In precipitating copper from sulphate solutions by electrolysis, using insoluble anodes, Hartmann prevents polarisation by saturating the solution with sulphurous anhydride aud heating it.The electro- lytic purification of copper is discussed in detail by Kiliani in the original paper (see also Bergund, Hi&. Zeit., 1885, 249). Demercurising Gold. By B. FISCEER (Chern. Centr., 1885, 447).-The gold is rubbed well with a paste of powdered iodine and alcohol, and then placed in strong potassium iodide solution. This process is repeated until all the mercury is dissolved, and the gold is then polished with whiting. Electrolytic Extraction of Gold. By H. R. CASSELL (Chem. Centr., 1885, 6'23-624 and 637-638) .-The author employs nascent chlorine, liberated from a chloride of sodium solution by electrolysis, as a solvent for the gold to be extracted. The chlorine appears to have a selective affinity for the gold, gold chloride being formed before any of the other metals present are acted on.The solution must be kept alkaline by the addition of slaked lime, as otherwise the hydrochloric acid which is always formed by the electrolptic process, acts on the iron present in the ore to form ferrous chloride, which a t once precipitates the gold that has gone into solution. As long as excess of lime is present, no ferrous chloride is formed. The apparatus employed consists of a vertical cylinder about 3 feet long and 4 feet in diameter, revolving in a wooden vat.The cylinder is isolated from the vat, and has its surface of porous material. The positive wire from the dynamo passes into the cylinder and terminates in a number of thick carbon rods, the negative wire ends in the vat, in zt roll of copper foil. Both vat and cylinder are charged with a strong solution of sa.lt, and the dynamo started. The pulverised ore is then gradually introduced into the upper end of the cylinder (which is given about ten revolutions per minute) so that in falling D. B. J. K. C.110 ABSTRACTS OF CHEMICAL PAPERS. it comes in contact with the positive poles of the battery. The process takes about four hours for completion. The solution con- taining all the gold can then be decanted or filtered off, and the gold precipitated by iron or other suitable substance.If the surface of the cylinder is covered with asbestos cloth, or other suitable filtering material, the gold chloride passes through, and the gold is then pre- cipitated as a black powder a t the copper negative pule, and may be collected and melted. This latter plan is the best in general practice. Solubility of Mercuric Iodide in Fatty Compounds and other Solvents. By C. MBHU (J. Pharm. [ 5 ] , 11, 249--255).-0iZ of sweet almonds heated on a steam-bath dissolves about 13 parts of iodide per 1000 of oil, but on cooling about two-thirds of this is deposited. Heated a t 180°, about 80 parts iodide per 1000 parts oil are dissolved, but 8 considerable proportion is deposited at 150" in yellow crystals, which rapidly pass into the red modification on the filter. About 4 parts per 1000 may be considered as the amount retained in the cold. This amount can be increased by the addition of potassium iodide.Olive &Z behaves in much the same manner as oil of sweet almonds. White oil at. 100" dissolves 15.35 parts of iodide per 1000. A solu- tion of 10 parts per 1000 remained quite clear when kept for six days in a cellar. Nut oil a t 100" dissolves about 15 parts per 1000, and retains 13 parts in the cold. Castor oil is one of the most powerful solvents for mercuric iodide. About 40 parts per 1000 are dissolved a t 100". About 20 parts are retained on cooling. A mixture of 80 parts iodide with 48 parts mercuric chloride is dissolved in 1000 parts of oil on the steam-bath, and on cooling only a small quantity of the mixture separates out.About 100 parts of a mixture of equal equivalents of the iodide and chloride are almost completely retained in solution by 1000 parts of oil. L. T. T. Potassium iodide largely increases the solubility of the iodide. Lard retains about 4.5 parts iodide per 1000 in the cold. Vaseline dissolves only about 0.25 part per 1000. Phenol retains less than 10 parts per 1000. Bei~zewe dissolves 20 grams a t loo", but retains only 4 parts per 1000 in the cold. The author has experimented with mercury benzoate and other compounds, with a view to obtaining oils containing metallic com- pounds, but the results obtained with mercuric iodide appear most valuable. J. T. Preparation of Ferrocyanides. By A. STERNRERG (Din g l . polyt. J., 257, 539).-The author has found that the sulphur contained in the thiocyanogen-group CNS is readily given up to a metal if the latter can form ferrocyanides simultaneously.The thiocyanate to be treated is mixed with twice the weight of iron filings required to form iron sulphide, and twice the a,mount of freshly precipitated ferrous hydroxide required to form ferrocyanide. The mixture is agitated in a closed vessel a t 110--120". After twelve hours' digestion aboutTECHNICAL CHEMISTRY. 111 80 per cent. of the thiocyanate will have been converted into Prussian blue and ferrocyanide. D. B. Improvements in the Manufacture of Sugar. (DingZ. pdyt. J., 257, 372-378 and 420--$31).-1t is stated by Koch that on storing beet highly manured with nitrogen, it loses much saccharine matter.Van Hennekeler has recently tried Despeissis’ process of refining sugar by electrolytic means. He found that the mineral constituents pass from the positive to t$e negative pole, and that the amount of cane-sugar a t the positive pole is augmented. Landolt has attempted the destruction of the colouring matters in beet juice by electricity, but has been unsuccessful. I n discussing the processes used for refining beet-juice, Degener observed that for the treatment of bad roots the sulphurous acid process was indispensable, on account of the antiseptic properties of this acid. Although, according to Bergmann, it is more economical and less troublesome to refine without animal charcoal, the quantity of sugar yielded is largely affected. Experiments conducted a t the Dahmen Sugar Works proved that with the use of animal charcoal it was possible to obtain about 8 per cent.more sugar, a8 against a saving in working expenses of 6 pfennigs per 100 kilos. of beet realised when animal charcoal was not employed. According to Frost, an important element in the success of the defecation process is the use of lime in a finely divided state, and its freedom from grit. Steffen recommends heating the waste liquors and removing the last portions of calcium saccharate by hot filtration. The latter may then be added to fresh molasses, or washed with hot water and mixed with calcium saccharate from preceding operations. Bodenbender, in referring to the determination of invert sugar, an operation of some importance as it is required by the English market, observed that other substances present in beet affect copper solutions in a manner similar to invert sugar.To obtain results approaching nearer to accuracy, it is suggested that the sugar under treatment should be titrated with Fehling’s solution before and after boiling with caustic soda. The use of Schmidt and Hansch’s polarisation apparatus is recommended by Sickel. Landolt doubts the accuracy of plates of quartz, and expresses the opinion that more trustworthy results are obtained when polarising apparatus are tested with saccharine solu- tions of definite composition. Kleemann proposes the use of pulverised lignite for the purification of saccharine juices. Degener has made a series of experiments with the object of studying the influence of lead acetate on the optical behaviour of certain nonsaccharine substances present in beet-juice.He finds that lead acetate converts the levo-rotation of asparagine into a d e x t r o p a t e action. The laevo-rotation of the potassium salt under- goes a similar change when an excess of lend acetate is used. Alcohol increases the rotary power of this salt. Glutamic acid is dextro-112 ABSTRACTS OF CHEMICAL PAPERS. rotary, and insoluble in alcohol. Its potassium salt is soluble i n alcohol. Lead acetate imparts to glutamic acid a laevorotary action. Malic acid is lzevorotary, its optical power however depends on the concentration and alkalinity of its soliitions. Alcoholic solutions are optically inactive. The malates are insoluble in alcohol, but, in the presence of a large excess of lead acetate a laevorotary action is obtained.Arabic acid, if present in small quantities, does not affect the polarisation of saccharine juices. Tartaric acid is optically inactive. Caustic alkalis or carbonates impart to saccharose a Zaevorotary action. Lead acetate first decreases the dextrorotary power of saccharose, and finally changes it t o lsevo-rotation. Aqueous solutions of albumin are not precipitated by lead acetate. I n spite of these reactions Degener concludes that the degree of accuracy obtainable with the methods involving the use of alcohol and lead acetate is illfinitely greater than that obtained by the use of other processes hitherto recommended. It is necessary, however, to adhere strictly to the conditions as to the proportion of alcohol and sugar (3 vols.t o 1 vol.), and to moderate the quantity of lead acetate employed as much as possible. (DhqZ. poZyt. J., 25 7, 812.) -According to the Budische -4nilin urtd Xodufubrik, tetrachlorindigo is obtained by treating orthonitrodichlorobenzaldehyde witb acetone and caustic soda. A dye is produced which closely resembles indigo. (Compare Absfr., 1884, 1028.) Percentage of Water in Different Wood-papers. By B. LEPSIUS (Ber., 18, 2491--2492).-1n commerce, paper is bought by its '' air-dry " weight, and this is taken as the weight, a t 100" + 12 per eerit. added for moisture. The author has examined several papers, and finds that whereas for mechanically-pulped aspen and pine papers (holzschleifstoffen) this is true, for chemically-prepared (soda, or sul- phite processes) cellulose papers the addition should only be 10 per cent.L. T. T. Chemical Products of Putrefaction in their Relation to Dis- infection, By B. SANDERSON (Pharm. J. Trans. [3], 15, 897-898, 911-912, and 991-992), from the Thirteent.h Annual Report of the Local Government Board. Modification of Siemens' Pyrometer. By J. SPOHR (Dingl. pobyt. J., 257, 315).-The author proposes the use of the telephone in the place of the Toltameter. High Pressure Digesters (Autoclaves) for Chemical Labo- ratories. By R. MUENCKE (Dingl. polyt. J., 25 7, 283) .-The appa- ratus consists of a cylindrical copper vessel, provided with a cover, which is firmly fastened down by a screw. In order to close the vessel hermetically a leaden ring is placed between the edge8 of the cover and the vessel.For low tensions (under 25 atmos.) the cover is made of gun-metal or cast iron, whilst for higher tensions phosphor- bronze is employed. The interior of the cylinder may be lined with lead or enamelled as required. D. B. Preparation of Tetrachlorindigo. D. B. D. B. D. B.106 ABSTRACTS OF CHEMICAL PAPERS.T e c h n i c a l C h e m i s t r y .Oxalate Developer for Gelatin Plates. By H. W. LORD(Chew, Cmtr., 1885, 668).-10 grams of sodium sulphite are dis-solved in 175 C.C. of a concentrated solution of potassium oxalate and50 C.C. of a concentrated solution of ferrous sulphate added. About1 C.C. sulphuric acid is then dropped in, until the mixture smells ofsulphurous acid. This forms a very energetic developer, and thesame quantity may be used several times.L. T. T.New Photographic Copying Paper. By H. J. SHAWCROSS(Chenz. Ceiztr., 1885, 668) .-The author covers the prepared paperwith the powdered solid developer (tnnnic acid or other compoundgiving coloured precipitates with ferric but none with ferrous salts),which is well rubbed in. After exposure under the drawing to becopied the paper is laid in water, and the excess of developer removedwith the aid of a sponge. A separate developing bath is thusavoided. L. T. T.Electric Aecumulators. By S. SCHENEK and S. FARBAKY (Dingl.polyt. J., 257, 357-369 and 458465).-1n 1883 the Academy ofMining and Forestry in Schemnitz, Hungary was furnished withincandescent lamps, the electric current being supplied by about90 accumulators.The present paper describes the constructionof the accnmulators employed, and gives an account of some observa-tions made by the authors. To study the behaviour of the sulphuriTECHNICAL CHEMISTRY. 107acid during the condensation and the discharge of the current,a series of experiments was made. It was found that when theaccumulators are charged the sulphates are decomposed, sulphuricacid being liberated, whilst on discharging, the sulphates areagain formed, the free acid being recombined. To determine the,ratio of accrnmulated energy to acid set free, and the ratio of dis-charged energy to acid fixed, a further series of trials had to be made.The results appear to show that when the acciimulators are charged,2.23 grams of sulphuric acid are liberated per ampitre per hour, andthat during their discharge 2.25 gmms of acid are fixed, giving amean value of 2.24.The authors term this number the electro-chemical equivalent of sulphuric acid for an electric force of oneamfire per hour. From this value, some useful data in regard to thepreparation, treatment, and application of electric accumulators aresaid to be derived.Selenium Battery. By C. E. FRITTS (Diiigl. polyt. J., 258, 44).-The author in conjunction with Hopkinson has patented seleniumcells of a certain construction, capable ot generating a current ofelectricity under the action of rays of light. A description of thisbattery is given in the original paper and more fully in Engineering,39, 398 (see also this vol., p.2).Gas Analyses. By F. FISCRER (Dirtgl. polyt. J. 258, 28).-Analyses of the gases from regenerative furnaces of the Hasse-Didiertype and from pyrites kilns are given.Liquid Carbonic Anhydride. By H. HERBERTS (Chew,. Centr.,188.5, 543-5444 558-560, and 57d).-The author describes in detailthe various methods at present employed f o r the manufacture of thisproduct on the large male, as well as the objects and uses to which itmay be applied. He has patented an apparatus and method formaking the gas by the action of sodium bisnlphite ou a suitablecarbonate, and also describes a process for obtaining it from alkalinebicarbonates. He proposes to employ liquid carbonic anhydride as amotive power where fuel is expensive.Further Experiments on the Decomposition of AmmoniumSulphate by Means of Sodium Sulphate. By G.BLATTNER(Dingl. polyt. J., 25 7, 4?4--479).-1n a previous communication(Abstr., 1885, 613), the author gave an account of some experi-ments made with the view of testing the correctness of Careyand Hurter’s reaction of obtaining ammonia from ammoniumsulphate by decomposition with sodium sulphate, the sulphuricacid being utilised simultaneously. These experiments were madewithout the use of superheated steam, and it was found thatfrom 1 5 t o 18 per cent, of the ammonia originally present in theammonium sulphate employed was lost by decomposition. The objectof the present investigation was to ascertain whether by the use ofsuperheated steam it was possible to avoid the loss of ammonia orto reduce it to a minimum.The results showed that although the lossof ammonia was diminished (to from 1 to 3 per cent.), a large pro-D. B.D. B.I). B.J. K. CI08 ABSTRACTS OF CHEMICAL PAPERS.portion remained in the residue, and sublimed in the form of hydrogenammonium sulphate, only from SO t o 90 per cent. of the ammoniabeing liberated as such, The author considers that the success of thisprocess on a large scale depends on the complete removal of thesedifEcul ties. D. B.Treating Celestin and Heavy Spar. By I?. KONTHER (Dingl.polyt. J., 258, 46).-Heavy spar, celestin, or gypsum is introducedinto fused sodium or potassium chloride, when the impurities sink tothe bottom.The fused mass is then drawn off, cooled, and lixiviatedwith water, the object being to obtain the sulphates in a finely dividedstate suitable for further chemical treatment (with sodium carbonate,ammonium carbonate, &c.). The resulting mass may be used also asa pigment for stucco-work, &c.Treating Raw Phosphates. By P. DIETRICH (DingZ. poZyt. J.,25 7 , 484) .-Crude phosphates containing calcium oxide or carbonateare treated with sdphurous anhydride to form gypsum, so that bythe subsequent treatment with dilute acids only tlhe phosphate isattacked. To effect the complete conversion of the calcium oxide intogypsum, a mixture of air and sulphurous anhydride is allowed toact on the phosphate in the presence of superheated steam.D.B.D. B.Preparation of Alumina. By G. ROSENTHAL (Dingl. polyt. J.,257, 539) .-On evaporating a solution of aluminium sulphate andmagnesium chloride, alumina, magnesium sulphnte, and hydrochloricacid are obtained. The residue is mixed with a small amount ofcaustic lime, and subjected to the action of superheated stea,m a t300". After lixiviation, alumina mixed with ferric oxide remains.Owing to the higher specific gravity of the latter, its separationfrom the alumina may be effected by elutriation. D. B.Preparation of Chromic Acid. By W. A. ROWELL (Dingl.polyt. J., 258,47).-It is proposed to treat the solution of a chromatewith a soluble stront'ium salt, a precipitate of strontium chromatebeing obtained. The filtrate, contaiiiing some strontium chromate insolution, is treated with barium chloride.The barium chromate thusformed is decomposed with hot dilute sulphuria acid in large excess.The mixture of dilute chromic and sulphuric acids having beenseparated from barium sulphate is treated hot with an amount ofstrontium chromate equivalent to the sulphuric acid present. Thisresults in the formation of chromic acid. which is seDarated from theprecipitate of strontium sulphnte and evaporated to dryness.D. B.Irregularities in the Composition of Steel Ingots. ByP. ZETSCHE (Dingl. yoZyt. J., 258, 2l).--From an examination of thecomposition of different sections of steel ingots, the author infers thatthe metttlloids sulphur and phosphorus predominate in the innerparts of the castings, whilst silicon and manganese are found mainlyin the outer portions, D, BTECHNICAL CHEMISTRY.109Improvements in Metallurgy. (Dingl. polyk. J., 258, 31-39.)-To work up tin scrap, Lambotte proposes subjecting the metalto the action of dilute gaseous chlorine a t a temperature exceeding theboiling point of chloride of tin. The rapours of stannic chlorideevolved are condensed in chambers or passed into a solution of stannicchloride.For the production of an alloy of high conductivity Shaw mixes100 parts of copper with 1 to 5 parts of aluminium, and adds 0.05 to1 part of phosphorus. The aluminium previously mixed with palmoil is gradually stirred into the fused copper. The phosphorus is thenintroduced, and the mass poured into flat moulds.Guillemin prepares alloys of copper and cobalt of great' firmnessand tenacity by fusing copper and cobalt with boric acid and charcoal.The tensile strengt,h of the resulting alloy amounted to 40 kilos.persquare mm. It contained 48.3 per cent. of cobalt, 50.3 per cent. ofcopper, 1 per cent. of nickel, and 0.4 per cent. of iron.According to Crooke molten lead does not take up the silver,arsenic, and antimony from copper ores unless it is mixed intimatelywith the ore at a temperature below the fusing point of copper.In precipitating copper from sulphate solutions by electrolysis,using insoluble anodes, Hartmann prevents polarisation by saturatingthe solution with sulphurous anhydride aud heating it. The electro-lytic purification of copper is discussed in detail by Kiliani in theoriginal paper (see also Bergund, Hi&. Zeit., 1885, 249).Demercurising Gold.By B. FISCEER (Chern. Centr., 1885,447).-The gold is rubbed well with a paste of powdered iodine andalcohol, and then placed in strong potassium iodide solution. Thisprocess is repeated until all the mercury is dissolved, and the gold isthen polished with whiting.Electrolytic Extraction of Gold. By H. R. CASSELL (Chem.Centr., 1885, 6'23-624 and 637-638) .-The author employs nascentchlorine, liberated from a chloride of sodium solution by electrolysis,as a solvent for the gold to be extracted. The chlorine appears tohave a selective affinity for the gold, gold chloride being formedbefore any of the other metals present are acted on.The solutionmust be kept alkaline by the addition of slaked lime, as otherwise thehydrochloric acid which is always formed by the electrolptic process,acts on the iron present in the ore to form ferrous chloride, which a tonce precipitates the gold that has gone into solution. As long asexcess of lime is present, no ferrous chloride is formed.The apparatus employed consists of a vertical cylinder about 3 feetlong and 4 feet in diameter, revolving in a wooden vat. The cylinderis isolated from the vat, and has its surface of porous material. Thepositive wire from the dynamo passes into the cylinder and terminatesin a number of thick carbon rods, the negative wire ends in the vat,in zt roll of copper foil. Both vat and cylinder are charged with astrong solution of sa.lt, and the dynamo started.The pulverised oreis then gradually introduced into the upper end of the cylinder(which is given about ten revolutions per minute) so that in fallingD. B.J. K. C110 ABSTRACTS OF CHEMICAL PAPERS.it comes in contact with the positive poles of the battery. Theprocess takes about four hours for completion. The solution con-taining all the gold can then be decanted or filtered off, and the goldprecipitated by iron or other suitable substance. If the surface ofthe cylinder is covered with asbestos cloth, or other suitable filteringmaterial, the gold chloride passes through, and the gold is then pre-cipitated as a black powder a t the copper negative pule, and may becollected and melted.This latter plan is the best in general practice.Solubility of Mercuric Iodide in Fatty Compounds andother Solvents. By C. MBHU (J. Pharm. [ 5 ] , 11, 249--255).-0iZof sweet almonds heated on a steam-bath dissolves about 13 partsof iodide per 1000 of oil, but on cooling about two-thirds of this isdeposited. Heated a t 180°, about 80 parts iodide per 1000 partsoil are dissolved, but 8 considerable proportion is deposited at 150"in yellow crystals, which rapidly pass into the red modification on thefilter. About 4 parts per 1000 may be considered as the amountretained in the cold. This amount can be increased by the additionof potassium iodide.Olive &Z behaves in much the same manner as oil of sweet almonds.White oil at. 100" dissolves 15.35 parts of iodide per 1000. A solu-tion of 10 parts per 1000 remained quite clear when kept for six daysin a cellar.Nut oil a t 100" dissolves about 15 parts per 1000, and retains13 parts in the cold.Castor oil is one of the most powerful solvents for mercuric iodide.About 40 parts per 1000 are dissolved a t 100".About 20 parts areretained on cooling. A mixture of 80 parts iodide with 48 partsmercuric chloride is dissolved in 1000 parts of oil on the steam-bath,and on cooling only a small quantity of the mixture separates out.About 100 parts of a mixture of equal equivalents of the iodide andchloride are almost completely retained in solution by 1000 parts ofoil.L. T. T.Potassium iodide largely increases the solubility of the iodide.Lard retains about 4.5 parts iodide per 1000 in the cold.Vaseline dissolves only about 0.25 part per 1000.Phenol retains less than 10 parts per 1000.Bei~zewe dissolves 20 grams a t loo", but retains only 4 parts per1000 in the cold.The author has experimented with mercury benzoate and othercompounds, with a view to obtaining oils containing metallic com-pounds, but the results obtained with mercuric iodide appear mostvaluable.J. T.Preparation of Ferrocyanides. By A. STERNRERG (Din g l . polyt.J., 257, 539).-The author has found that the sulphur contained inthe thiocyanogen-group CNS is readily given up to a metal if thelatter can form ferrocyanides simultaneously. The thiocyanate to betreated is mixed with twice the weight of iron filings required to formiron sulphide, and twice the a,mount of freshly precipitated ferroushydroxide required to form ferrocyanide.The mixture is agitated ina closed vessel a t 110--120". After twelve hours' digestion abouTECHNICAL CHEMISTRY. 11180 per cent. of the thiocyanate will have been converted into Prussianblue and ferrocyanide. D. B.Improvements in the Manufacture of Sugar. (DingZ. pdyt. J.,257, 372-378 and 420--$31).-1t is stated by Koch that onstoring beet highly manured with nitrogen, it loses much saccharinematter.Van Hennekeler has recently tried Despeissis’ process of refiningsugar by electrolytic means. He found that the mineral constituentspass from the positive to t$e negative pole, and that the amount ofcane-sugar a t the positive pole is augmented.Landolt has attemptedthe destruction of the colouring matters in beet juice by electricity,but has been unsuccessful.I n discussing the processes used for refining beet-juice, Degenerobserved that for the treatment of bad roots the sulphurous acidprocess was indispensable, on account of the antiseptic properties ofthis acid. Although, according to Bergmann, it is more economicaland less troublesome to refine without animal charcoal, the quantityof sugar yielded is largely affected. Experiments conducted a t theDahmen Sugar Works proved that with the use of animal charcoal itwas possible to obtain about 8 per cent. more sugar, a8 against a savingin working expenses of 6 pfennigs per 100 kilos. of beet realised whenanimal charcoal was not employed.According to Frost, an important element in the success of thedefecation process is the use of lime in a finely divided state, and itsfreedom from grit.Steffen recommends heating the waste liquors and removing the lastportions of calcium saccharate by hot filtration.The latter may thenbe added to fresh molasses, or washed with hot water and mixed withcalcium saccharate from preceding operations.Bodenbender, in referring to the determination of invert sugar, anoperation of some importance as it is required by the English market,observed that other substances present in beet affect copper solutionsin a manner similar to invert sugar. To obtain results approachingnearer to accuracy, it is suggested that the sugar under treatmentshould be titrated with Fehling’s solution before and after boilingwith caustic soda.The use of Schmidt and Hansch’s polarisation apparatus isrecommended by Sickel.Landolt doubts the accuracy of plates ofquartz, and expresses the opinion that more trustworthy results areobtained when polarising apparatus are tested with saccharine solu-tions of definite composition.Kleemann proposes the use of pulverised lignite for the purificationof saccharine juices.Degener has made a series of experiments with the object ofstudying the influence of lead acetate on the optical behaviour ofcertain nonsaccharine substances present in beet-juice. He findsthat lead acetate converts the levo-rotation of asparagine into ad e x t r o p a t e action.The laevo-rotation of the potassium salt under-goes a similar change when an excess of lend acetate is used. Alcoholincreases the rotary power of this salt. Glutamic acid is dextro112 ABSTRACTS OF CHEMICAL PAPERS.rotary, and insoluble in alcohol. Its potassium salt is soluble i nalcohol. Lead acetate imparts to glutamic acid a laevorotary action.Malic acid is lzevorotary, its optical power however depends on theconcentration and alkalinity of its soliitions. Alcoholic solutions areoptically inactive. The malates are insoluble in alcohol, but, in thepresence of a large excess of lead acetate a laevorotary action isobtained. Arabic acid, if present in small quantities, does not affectthe polarisation of saccharine juices. Tartaric acid is opticallyinactive.Caustic alkalis or carbonates impart to saccharose aZaevorotary action. Lead acetate first decreases the dextrorotarypower of saccharose, and finally changes it t o lsevo-rotation. Aqueoussolutions of albumin are not precipitated by lead acetate. I n spiteof these reactions Degener concludes that the degree of accuracyobtainable with the methods involving the use of alcohol and leadacetate is illfinitely greater than that obtained by the use of otherprocesses hitherto recommended. It is necessary, however, to adherestrictly to the conditions as to the proportion of alcohol and sugar(3 vols. t o 1 vol.), and to moderate the quantity of lead acetateemployed as much as possible.(DhqZ. poZyt. J., 25 7, 812.)-According to the Budische -4nilin urtd Xodufubrik, tetrachlorindigois obtained by treating orthonitrodichlorobenzaldehyde witb acetoneand caustic soda. A dye is produced which closely resembles indigo.(Compare Absfr., 1884, 1028.)Percentage of Water in Different Wood-papers. By B.LEPSIUS (Ber., 18, 2491--2492).-1n commerce, paper is bought by its'' air-dry " weight, and this is taken as the weight, a t 100" + 12 pereerit. added for moisture. The author has examined several papers,and finds that whereas for mechanically-pulped aspen and pine papers(holzschleifstoffen) this is true, for chemically-prepared (soda, or sul-phite processes) cellulose papers the addition should only be 10 percent. L. T. T.Chemical Products of Putrefaction in their Relation to Dis-infection, By B. SANDERSON (Pharm. J. Trans. [3], 15, 897-898,911-912, and 991-992), from the Thirteent.h Annual Report of theLocal Government Board.Modification of Siemens' Pyrometer. By J. SPOHR (Dingl.pobyt. J., 257, 315).-The author proposes the use of the telephone inthe place of the Toltameter.High Pressure Digesters (Autoclaves) for Chemical Labo-ratories. By R. MUENCKE (Dingl. polyt. J., 25 7, 283) .-The appa-ratus consists of a cylindrical copper vessel, provided with a cover,which is firmly fastened down by a screw. In order to close thevessel hermetically a leaden ring is placed between the edge8 of thecover and the vessel. For low tensions (under 25 atmos.) the cover ismade of gun-metal or cast iron, whilst for higher tensions phosphor-bronze is employed. The interior of the cylinder may be lined withlead or enamelled as required.D. B.Preparation of Tetrachlorindigo.D. B.D. B.D. B