96 ABSTRACTS OF CHEMICAL PAPERS. A n a 1 y t i c a 1 Chemistry. Apparatus for the Quick Reduction of Measured Gas Volumes to Normal Condition. By C. WINKLER (Be?.., 18,2533- 2535).-A modification o€ Kreusler's apparatus (Abstr., 1884, 775). New Arrangement of the Volumetric System. By C. WINKLER (Ber., 18, 2527-2533) .-The author thinks that the volumetric system should be derived from the molecular weights, and not from the equivalent weights, as is the case a t present. A Method of Filtration by Means of easily soluble and easily volatile Filters. By F. A. GOOCH (Amer. Chem. J., 7,87- 90).-Anthracene is proposed as a substitute for asbestos for filtering in cases where the use of paper is objectionable. The anthracene is moistened with alcohol, then mixed with water, and applied to a per- forated cone or crucible in the same way as asbestos.If necessary, a finer coating, made by dissolving anthracene in hot alcohol and pre- cipitating by water, is afterwards added. .After filtration, the anthra- cene may be removed by treating in a small beaker with warm benzene ; on adding water the benzene solution rises, and may be removed by filtration through a wet filter-paper if thought necessary. The anthracene may also be removed by gentle heating. H. B. Estimation of Water of Crystallisation in Organic Corn- pounds By E. OSTERHAYER (Chem. Celztr., 1885, 603-604) .-The method described by the author is one employed to estimate the amount of water in the salts of iodonaphtholsulphonic acid, which, like many other organic compounds, loses iodine on heating.A weighed quantity of the salt is heated in a current of dry air in a tube placed in an oil-bath a t 110-120" ; the tube is connected with one containing a silver spiral, and this with a chloride of calcium tube. The silver is gently heated, and combines with the iodine given off, whilst the water is collected by the calcium chloride, the increase in weight of the latter giving the amount of water. Diphenylamine as a Reagent for Free Chlorine. By H. HAGER (Chem. Centr., 1835, 588).-As a very delicate test for traces P. P. B.ANALYTICAL CHEMISTRY. 97 of free chlorine, the author nses a solution of diphenylamine in strong sulphuric acid, poured gently down the side of the vessel containilig the liquid to be t,ested. Should no blue coloration be formed, even after standing for a few minutes with subsequent agitation, a small quantity of pure concentrated sulphuric acid should be added, when even very small traces of free chlorine will show themselves bv a blue ring forming a t the junction of the two liquids.Naphthol as a Reagent for Free Chlorine and Bromine. Bp H. HAGER (Chem. Centr., 1885, 692--693).-A 1 per cent. alcoholic solution is used ; about; 0.5 C.C. of this is poured gently into a narrow cylinder containing 4-5 C.C. of the liquid to be tested. After standing for a few minutes, traces of free chlorine or bromine are shown by the formation of a; milky ring where the two liquids meet. Nitric acid and ferric chloride should be well diluted before apdying the test. J. K. C. J. K. C. Estimation of Iodine.By G. WEISS (Chem. Centr., 1885, 634, and ?12--713).-The author has lately received samples of iodine, which, when estimated by the ordinary method of titration with hyposulphite, gave over 100 per cent. of iodine. This was found to be due to the presence of about 3 per cent. of bromine, an impurity due to the fact that the iodine was obtained from the last mother- liquors in the preparation of nitre, by precipitation as cuprous iodide. The greasy nature of this precipitate renders the complete washing out of the chlorides and bromides present exceedingly uncertain. The author describes a simple method for the quantitative separa- tion of iodine, bromine, and chlorine. The halogens must be present in the form of simple and easily decomposable metallic compounds.Concentrated ferric sulphate solution is added and the whole boiled, when the following reaction takes place : Fe,(S04)9 + 2KI = 2FeS04 + KZSO, + Iz. During the heat'ing, a current of air is passed through the solution, and then into a solution of potassium iodide. When all the iodine has been carried over int,o this latter, it is removed for titra- tion and replaced by dilute ammonia. After the residue in the decomposing flask has cooled, a slight excess of potassium perman- ganate is added to it, and the flask warmed to 50-60". Evolution of bromine soon commences, and the latter is carried over into the ammonia by the current of air, and thvn estimat,ed gravimetricdly or by titration. The chlorine can be estimated in the residue, or better, by difference, from a determination of the total quantity of iodine, bromine, and chlorine present in the original substance.If the halogens are present as oxy-acids, they must be reduced by sulphuretted hydrogen o r other suitable means ; if in the free state they are best converted into zinc iodide by treatment with zinc-dust. L. T. T. Detection and Determination of Fluorine. By G. TAMMANX (Zeit. anal. Chem., 24, 328-343) .-Fresenius' method (Zeit. anal. Chew., 5, 190) of absorbing t,he silicon fluoride by water and weighing gives good results. For destroying admixed carbonates, evaporation with potash-alum is as effective as boiling with acetic acid. Sulphurous VOL. L. h98 ABSTRACTS OF CHEMlOAL PAPERS. anhydride may be arrested by a tube containing chromic acid dissolved in strong sulphuric acid. This does not retain silicon fluoride; whereas solutions of potassium dichromate and permanganate in sulphuric acid, and peroxide of lead as proposed by Kupfer, all absorb the fluoride.I n substances free from boron, fluorine may be detected by heating with quartz powder and sulphuric acid a t 170" in a stream of air, which is then passed through water. As little as 0.0002 gram of fluorine yields a ring of silica in the wetted part of the tube. The water will then contain hydrofluosilicic acid, besides silica, sulphuric acid and a trace of sulphurous acid. Hydrofluosilicic acid is best precipitated by an alcoholic solution of barium bromide or acetate. Barium silicofluoride can be completely washed with 50 per cent. alcohol, 1 litre of which dissolves 0.0257 gram of it.If evaporation be required, the acetate must be used, since acetic acid does not expel hydrofluosilicic acid, whilst hydrobromic acid does. The acetate ~hould be strongly acidified, and the residue must be treated with hydrobrornic acid, to reconvert into silicofluoride any barium fluoride which may ha,ve been formed. It is then washed with 75 per cent. alcohol, converted into snlphate and weighed. Test analyses showed that even in highly dilute solutions, the fluorine can be thus deter- mined without serious loss. Soluble fluorides can be annlysed in similar manner after conversion into silicofluorides by addition of hydrobromic acid and silica. The excess of silica is removed by hydrofluoric a d d after the washing with alcohol.Barium silicofluoride may be separated from the sulphate by igniting the mixture, and extracting the fluoride of barium by hydrochloric acid. Attempts to determine fluorine in fluorspar and cryolite by the above processes gave very low results, owing to the fact observed by Landolt, that the action of moist air on silicon fluoride produces an insoluble compound containing fluorine (5-12 per cent.). This body is not decomposed by evaporation with baryta, but is easiIy solubIe in potash. This led to the following method, which gave good results. To the water in which the silicon fluoride has been absorbed, an excess of potash is added, and the whole evaporated to dryness. The residue is treated with hydrochloric acid, and excess of potassium acetate added.It is then mixed with 3 vols. of 80 per cent. alcohol, and the precipitated potassium silicofluoride titrated with potash (Stolba). The same process may be applied without distillation to soluble fluorides, adding silica before the acid, but with fluorspar, &c., distilla- tion is necessary. Lastly, the author condemns Wilson's method for estimating fluorine in organic compounds, and shows that a loss of from 7 t,o as much as 68 per cent. of the fluorine may take place during the incinera- tion alone, even when much sodium carbonate or baryta is added. M. J. S. Estimation of Carbon in Iron and Steel. By W. GINTL (BingZ. poZyt. J., 257, 527).-The estimation of carbon in iron, according to Wohler's method-heating in a current cif chlorine and igniting the residue to convert the carbon into carbonic anhydride-isANALYTICAL CELEMlSTRY.99 said to give low results, owing to the difficulty of obtaining chlorine free from oxygen. The author proposes to wash and dry the gas carefully, and pass it over a layer of red-hot charcoal, pre- viously ignited in a current of chlorine before applying it to Wiihler's method. D. B. Detection of Thiosulphates i n Water- By G. NEUHUFFER (Chem. Cmty., 16, 459)-Such impurities are to be found in the water obtained from the neighbourhood of gasworks, and at times from those in the neighbGurhood of vineyards. The presence of thio- sulphates may be ascertained by adding lead acetate to a litre of the water, collecting the precipitate, washing, and boiling it with sodium carbonate solution.The filtmte is evaporated to dryness, and the residue is tested for thiosulphates by treating it with hydrochloric acid and pure zinc. P. P. B" Ferrous Ammonium Sulphate as a Reagent for Nitric Acid, By A, ROSA (Gazxetta, 15,295-296) .-Ferrous ammonium snlphate is a delicate reagent for the presence of nitric acid ; it is much more sensitive than ferrous sulphate (compare Abstr., 1884, 493). U. H. V. Diphenylarnine and Crystallised Phenol as Reagents for Nitrates and Nitrites. By H. HAGEB (Chem. Centr., 183.5, 536- 588).-As stock solution, 1 gram of diphenylamine is dissolved in 30 C.C. of absolute alcohol and mixed with four or five times its bulk of pure concentrated sulphuric acid. The liquid to be tested is poured into a test-tube, and the diphenylamine solution allowed to run gently down the side: nitric or nitrous acid in the strength of one drop of a 30 per cent.solution to 60 C.C. of water is easily detected by this test, a blue coloration being formed at the point of contact of the two liquids. The absence of all ohher axidiz- ing or reducing substances must of course be first asoentained. That the blue coloration is not due to chlorine may be ascertained by a control experiment with crystallised phenol in hydrucldoric acid : the liquid to be tested is mixed with this in a test-tube, and sulphuric acid poured gently down the side : a, red coloration is. formed by the presence of nitrogen acids. J. I(. C. Naphthol and Sulphuric Acid as a Reagent for Nitric and Nitrous Acids and Free Chlorine. By H. HAGEE (Chem, Centr., 1885, 693-694).-Mix the liquid to be tested with half its bulk of a, 1 per cent.alcoholic naphthol solution, and pour sulphuric acid gently down the side of the vessel: a brownish-red coloration denotes the presence of nitrogen acids or free chlorine : if no ring is formed, shake up, allow t o stand for a few minutes, and pour in gently pure con- centrated sulphuric acid. J. K. C. Arsenic in Bleaching Powder and in Potassium Chlorate. By L. GARNIER (J. Phann. [ 5 ] , 11, 9).-In 1881, Schlagdenhauffen and the author detected the prssence of arsenic in certain samples of hi4I00 ABSTRACTS OF CHEMICAL PAPERS. bleaching powder. The author reports that recently potassium chlorate, intended to be used in Fresenius and Babo’s method of arsenic estimation in organic matter, was found to contain decided traces of arsenic.The presence of the metal is ascribed to impurity in the chlorine employed in manufacturing the salt. J. T. Estimation of Arsenic in Ores, Mattes and Metallic Copper. By G. W. LEHMANN and W. MAGER (Amer. Chem. J., 7, 112--113). -R. Pearce’s met(hod (Enyin. Mi%. J., 1883, 256) is found to be the most trustworthy and convenient. The material is fused with nitre and sodium carbonate, and the filtered solution acidified with nitric acid and boiled. Silver nitrate and ammoni:t are added, the pre- cipitate of silver arsenate is washed, and the silver in it estimated by Volhsrd’s method. Metallic copper must be dissolved in nitric acid, and the arsenic precipitated as ferric arsenate by addition of a ferric salt and ammonia in excess; the precipitate obtained is treated as above.Satisfactory test analyses are given. H. B. Swedish Method of Testing for Arsenic. By A. ATTERBERG (Chem. Centr., 16, 600-602).-A small portion of the substance is treated in a test-tube with dilute hydrochloric acid, zinc and ferrous sulpbate. A plug of cotton-wool moistened with lead acetate is placed above the mixture, and in the mouth of the test-tube are sus- pended two strips of paper moistened with lead acetate and silver nitrate respectively. If the silver nitrate remains unaltered after 12 hours, the substance is declared free from arsenic. If arsenic is found by the above method, then the substance is distilled with hydrochloric acid and ferrous sulphate. A portion of the distillate is tested for arsenic as above, and in another portion, the arsenic is pre- cipitated RS sulphide, and metallic arsenic obtained from the sulphide by reduction with potassium cyanide and sodium carbonate in a current of carbonic anhydride ; the density of the arsenic mirror de- termining the condemnation, or otherwise, of the goods.The author proposes to evaporate the distillate with nitric acid: the arsenic is then obtained in the form of arsenic acid, the presence of which can be easily recognised by the characteristic reaction with silver nitrate. Eyster’s Scheme for Qualitative Analysis. By R. B. WARDER P. P. B. (Arner. Chem. J., 7, 110-112). Eyster’s scheme is described in Amer. Chem. J., 7, 21-26 ; a modification is here proposed for the detection of cadmium, copper, nickel, and cobalt : the cadmium is precipitated by ammonium sulphide in presence of potassium cyanide ; addition of acetic acid to the filtrate throws down the copper as sulphide, and On adding hydrochloric acid to the filtrate from this, nickel is pre- cipitated as sulphide, whilst the cobalt remains in solution.H. B. Separation of Iron and Aluminium. By M. ILINSPI and G. V. KEORRE (Ber., 18, 2728-2734).-The metals must be present as sul- phates or chlorides, as in the case of nickel and cobalt (this vol., p. 840). The very slightly acid solution is treated with an equal volume of 50 per cent. acetic acid, and an excess of nitroso-P-naphthol (dis-ANALYTICAL CHEMISTRY. 101 solved in 50 per cent. acetic acid), and the whole stirred.After 6-8 hours it is filtered, and the precipitated ferrinitrosonaph tho1 mashed, first with cold 50 per cent. acetic acid, t'hen with water, dried, ignited with pure oxalic acid, and weighed as Fe203. Ferrircitroso-p-nnphthoz, (CIoHsO-N0)3Fe, forms a voluminous brownish-black precipitate, soluble in warm moderately dilute hydro- chloric or sulphuric acid ; it is also soluble in glacial acetic acid and in alcohol. Benzene, aniline, and phenol dissolve it with formation of dark-brown solutions. Warm concentrated potash solution decom- poses it with formation of ferric hydroxide and a green potassium salt of nitrosonaphthol. Ferroiiitroso-P-na~hthol is formed when a very dilute solution of a ferrous salt is treated with an aqueous solution of nitroso-naphthol : the solution becomes green, and after a long time a separation of green flakes of ferronitrosonaphthol takes place.This compound is very susceptible towards free mineral acids, and is therefore not formed in a strong solution of ferrous sulphate. N. H. M. Estimation of Manganese. By DEEHL (Chem. Centr., 1885, 713-714) .-The author previously recommended the estimation of manganese in the presence of iron by precipitation of the mixed oxides, FerOs and MnO,, by hydrogen peroxide, conversion of these by ignition intoMn,O, and Fe203, and estimation of the iron by titra- tion and of the manganese by difference. He now finds that unless carbonates or organic salts of the fixed alkalis are present,, the old method of precipitation of the mixed oxides, Mn,O, and Fe?04, by bromine and ammonia, is as quick, and more exact.Volumetric Estimation of Manganese by Means of Potas- sium Chlorate. By W. HAMPE (Chem. Centr., 1885, 714--715).-1t is well known that potassium chlorate precipibates manganese as peroxide from a boiling solution in concentrated (1.4) nitric acid. The author employs this process in the estimation of manganese in alloys of manganese and iron, &c. The alloy is dissolved in boiling nitric acid, the peroxide precipitated, collected, and titrated. The results are very good. The process may also be used for the estima- tion of manganese in ores, &c. The presence of cobalt, lead, and bismuth is injurious, and necessitates a re-solution and second pre- cipitation of the peroxide. Sulphuric and hydrochloric acids, if present, must be removed by barium nitrate or by boiling with nitric acid respectively.L. T. T. L. T. T. Assay of Nickel Coins. By W. C . ROBERTS (Pharm. J. Trans. [3], 15, 1072).-Half a gram of the alloy is dissolved in a small quantity of nitric acid, 1.5 gram of strong sulphuric acid is added, and the whole evaporated to dryness. The residue is dissolved, diluted to about 60 c.c., put int,o a platinum dish which forms the negative elec- trode of an electric circuit, the positive electrode being a flat platinum spiral suspended in the liquid ; the solution should be distinctly acid ; two pint " gravity " cells are sufficient for the deposition of the cop- per, which is complete in 12 hours, when the copper is washed, &c.102 ABSTRACTS OF CHEMICAL PAPERS.The solution and washings are heated, made ammoniacal, any pre- cipitated iron removed, and evaporated to about 60 c.c., the solution is then put into a platinum dish, and electrolysed, using three cells ; the nickel is deposited forming a white, coherent layer. Nitrates must not be present except in the smallest possible quantity. D. A. L. Electrolysis of Molybdenum Solutions. By E I?. S b m H and W. S. HOSKINSON (Amer. Chem. J., 7, 90--92).-In a previous paper (Amer. Chem. J., 1, No. 5 ) if was shown that molybdenum could be completely separated by electrolysis from alkaline molybdic acid solu- tions, but only after a lapse of 100 hours. It, has since been found that precipitatisn is complete in two to three hours if the solutions employed are faintly acid or neutral.The dense black deposit is in all cases Mo2o3,3H20, and not metallic molybdenum, as stated in the Handaoorterbuch der Chenzie. A number of very satisfactory teat analyses are given. H. B. By J. HERZ (Chem. Certtr., 1885, 5'23),-200 C.C. of the beer are acidified with phosphoric acid, and 100 C.C. distilled over ; the amonnt of sulphurous acid in the distillate is finally determined as barium snlphate. Beer brewed a t the Court Brewery gave by this method from 0.00179 to 0.00261 gram SO2 per litre, whilst 0.00373 gram per litre represents the mean of the results obtained with 84 samples of different beers. In the light of these results, the author would regard as suspicious any beer which, when treated as above, .yields a distillate giving from 5-10 mgrms.of barium sulphate, and if above 10 mgrms. of barium sulphate there can be no doubt as to the presence of sulphites. Oxidation of Carbohydrates by Means of Chromic Acid. By C. F. CROSS and E. J. BEVAN (Chem. News, 52, 207-208).- Having observed considerable qcantities of carbonic oxide in the gas evolved during the oxidation of cellulose, sugar, &c., by means of a mixture of chromic and salphuric acids, the authors have resorted for quantitative work to a volumetric method, and have successfully employed a modification of Schei bler's carbonic anhydride apparatus for the purpose. The chromic acid is introduced in a small tube into a small flask connected with the apparatus, and containing the sub- stance mixed with stroug sulphuric acid, the levels are adjusted, and then the contents of the flask are mixed by inclining and shaking.The authors intend extending the application of this method. Estimation of Uric Acid. By E. LUDWIG (Ghem. Centr., 1885, 523).--100 C.C. of the urine are treated with magnesia mixture and an ammoniacal solution of silver nitrate ; in this way a precipitate of magnesium silver urate and magnesium ammonium phosphate is obtained. The precipitate is digested with a solution of potassium sulphide and filtered, the filtrate cont'ains potassium urate, from which, after concentration, the uric acid is precipitated by hydrochloric acid. The uric acid is collected on a filter of glass-wool, freed from sulphur by washing with carbou bisulphide, dried and weighed. If the urine Determination of Sulphurous Acid in Beer.P. P. B. D. A. L.ANALYTICAL CHEWISTRY. 103 contains albumin this must be first removed by boiling with solution of salt and acetic acid, and treating the filtrate as above. The author finds the precipitation of uric acid by hydrochloric acid is never complete, even after several days. P. P. B. The Detection of Adulteration. in Oils. By 0. C. S. CARTER (Amer. Chem. J., 7, 92-96).-Cotton-seed oil may be detected when added to olive oil or to lard oil, by adding 5 vols. of absolute alcohol and an equal volume of a 1 per cent. solution of silver nitrate in absolute alcohol ; if cot,ton-seed oil is present, the mixture will rapidly darken on warming to 84". The presence of much of the drying oils, such as linseed, hemp-seed, or poppy-seed oil, is shown by treatment with nitrogen peroxide ; they do not solidify from formation of elaidin. The ease and completeness with which an oil may be saponified is a valuable test ; lard oil saponifies easily ; shark-liver oil and African fish oil resist saponification.Detection of Fat Oils in Mineral Oils. By F. Lux (Zeit. anal. Chent., 24, 357--362).--Wben colza oil is heated with potassium, or sodium, or their solid hydroxides, soaps are formed. The higher the temperature, the more rapid is the saponification. Between 200" and 250" the soaps dissolve in the oil, which, on slight cooling, gelatinises or even solidifies (varying with the alkali used). Mineral oils simi- larly treated do not alter in fluidity. The author tested numerous mixtures of petroleum and lubricating oils with colza, linseed, and olive oils, and found that 2 per cent.of the fat oil in all cases, and per cent. in some, could be detected with certainty by the gelatini- sation which occurred on cooling, after 15 minutes' heating a t 300" with sodium or solid caustic soda. With less than 2 per cent., it is necessary to heat the test-tube in a paraffin-bath and to avoid agita- tion during both heating and cooling, but with larger proportions a short boiling over the free flame suffices. Examination of Oils containing Unsaponifiable Fats. By T. MORAWSKI aiid H. DEMSKI (Dinyl. polyt. J., 258, 39-42).-For the estimation of unsaponifiable fats in oils, the authors recommend the following method, having special reference to the difficulty experienced in completely separating the saponified oil from the unsaponifiable fat.10 grams of the oil are treated in a flask with -50 C.C. of alcohol and 5 grams of caustic potash dissolved in a small amount of water. The mixture is boiled for half an hour in a reflux apparatus. The liquid is then diluted with 50 C.C. of water, cooled as ra.pidly as possible, transferred to a separating funnel, and agitated with light petroleurn. The mixture is allowed to settle, the lower layer drawn off, and the petroleum washed repeatedly with water. To remove t'he last particles of water, the petroleum extract is first poured into a dry flask and then transferred to a, tared flask from which the petro- leum is expelled by distillation. Test for Adulteration in Butter. By A. WAGNER (Chem.Centr., 2885, 412--413).-This method depends on the fact that natural H. B. M. J. S. D. B.104 ABSTRACTS OF CHERlICAL PAPERS. butter forms an emulsion much more easily t,han other fats. About 0.6 gram of butter is put in a flask with 12 C.C. of water and 2 drops of a 2 per cent. soda solution, and the whole well shaken ; it is then heated on a water-bath at 37", and transferred to a separating funnel, being washed out with water at the same temperature. From time to time, the emulsion is allowed to run out, being replaced with water at 37" until the water becomes quite clear; it is then carefully run out, and after cooling, the walls of the funnel are covered with a finely divided cheese-like mass if pure butter has been operated'upon, but the presence of any other fat is made apparent by oily drops which are visible also during the previous process.J. K. C. Critical and Experimental Study of the Knop - Hiifner Method of determining Urea. By C. JACOBJ (Zeit. anaZ. Chern., 24, 307-328).-The author defends the hypobromite process against the objections of Arnold (Bbstr., 1883, 1141), and maintains that if the operation be carried out in a uniform way, the use of an empirical constant for calculabing the nitrogen into urea will always give satisfactory results. Hufner by using 5 C.C. of a 1 per cent. urea solu- tion and 100 C.C. of Knop's original bypobromite reagent, obtained 354.3 C.C. of nitrogen (at 0" and 760 mm.) from 1 gram of urea. Using this constant, the author made a series of determiuations with pure urea solutions, varying in strength from 0.666 to 3.0 per cent. by both the Liebig-Pfluger and the Knop-Hiifner methods, and found that the latter gave on the whole the smaller errors.These were in almost all cases errors of deficit, and the deficiency increased some- what-though not proportionally-with the strength of the urea solution, whilst Liebig's method gave more irregular results, some- times much above the truth. With normal urine, and also with that of fever patients, Liebig's method invariably gave higher numbers than Hufner's, the difference being greatest with the pathological urine. With diabetic urine, containing 3 or 4 per cent. of sugar, Hufner's method still gave the lower numbers, but with a specimen containing 6 per cent., the use of the constant 354.3 led to a result higher than that yielded by Liebig's process. Determinations by both methods in solutions of pure urea, to which varying quantities of grape-sugar had been added, showed that the amount of nitrogen liberated increases with increasing quantities of sugar, although with as much as 6 per cent.it did not reach its theoretical limit. Sub- stituting f o r the sugar 1 to 5 per cent. of ethylic acetoacetate (the presence of which in diabetic urine has been suspected), practically the theoretical quantity of nitrogen was obtained, instead of the usual deficiency of 8 per cent., and with healthy urine, to which 1 per cent. of the ether had been added, the use of the theoretical constant 371.4 gave approximately the same results as the use of 354.3 in the ab- sence of the ether.Liebig's method gave higher results, supporting the view that mercuric nitrate precipitates other substances from urine besides urea. The author recommends that 4 per cent. of the ether should be added to diabetic urine, and the constant 371.4 used in the calculation. Finally it is argued that the results of this method are affectedANALYTICAL CHEMISTRY. 105 only to an insignificant extent by the other nitrogenous constituents of urine, except albumin and ammonia salts, of which the former is easily removed, and the latter, even if it be not right to calculate it as urea (which is almost certainly formed in the system by the de- hydration of ammonium carbonate), can be determined by Schlosing's or Schmiedeberg's method, and allowed for.M. J. S. Presence of Glutamine in Sugar-beet. By E. SCHULZE and E. BOSSHARD (Landw. Versuchs-Xtat., 1885, 129--136).-1n a previous communicat,ion (Abstr., 1885, 658), the authors have shown that glutaminc can be precipitated by means of mercuric nitrate from the juice of sugar-beet ; Scheibler has also obtained glutamic acid from beet molasses. In this paper the method employed to precipitate and estimate the glutamine in the crude juice is described; the quantity (1 gram per litre) obtained by this process is far below that which is really present (5.96 grams per litre) ; the difference is due to the imperfect precipitation, &c. It is this glutaminc which, after boiling, is converted into the glutamic acid detected by Scheibler. Estimation of Alkaloids in the Leaves of Atropa Bella- donna.By W. R. DUNSTAN and P. RANSOM (Pharm. J. Tyans. [3], 16, 237-238).--20 grams of dried and finely-powdered leaves are exhausted with about 100 C.C. of absolute alcohol. The alcoholic liquid is diluted with about an equal volume of water slightly acidified with hydrochloric acid, warmed and extracted with chloroform to remove chlorophyll, fat, &c. The aqueous residue is rendered alkaline with ammonia and again extracted with chloroform. The chloroform solution on evaporation leaves a residue of the pure alkaloid which is dried at 100" and weighed. Foreign leaves have been found to con- tain 0.22 per cent. total alkaloid, and English leaves overheated in drying 0.15 per cent. E. W. P. D. A. L. Sulpho-conjugate Colouring Matter in Wines. By CARLES (J.Phscrm. [5], 11, 109--110).-The author finds that the method recommended for the detection of these colouring matters in wine is not generally applicable. It consists in removing sulphates by means of barium chloride, removing the barium salt by means of an alkaline carbonate, then evaporatirig and calcining the residue ; sulphates thus produced are supposed to indicate the artificial colouring matters jn question. Erroneous results were obtained not only with wines known to be pure non-plastered, but also with wines made by the author from choice grapes in glass vessels (1) without any addition, ( 2 ) plastered with sulphurous gelatin. J. T. By W. CHLUDINSKY (Landw. Versuchs-Stat., 1885, 117--128).-The author describes his method of estimating the composition of fleeces, and enters into considerable detail concerning the apparatus (Eurianalyser) which he has designed for the removal of the grease by means of carbon bisulphide.As regards the composition of various wools, it is stated that the hygroscopic properties of different wools are almost Composition of Long-wool and Merino Fleeces.106 ABSTRACTS OF CHEMICAL PAPERS. identical ; merino fleeces have less impurity in them than other fleeces, but are richer in insoluble suint ; of other than merinos, Southdown fleeces are most largely contaminated with impurities, whilst the highest percentage of pure wools is found in fleeces from short-tailed sheep. E. W. P. Diagnosis of Keratin in Animal Tissues. By H. STEINBREGGE (Zeit. Biol., 21, 631--635).-The author has applied Ewald and Kuhne’s method (Verh.Med. Vereins z. Beidelberg, 1, 4.51) to the investigation of the tissues of the ear of mammalia for the presence of keratine as a normal constituent, which was a probability to be inferred from the morphological relationship of the tissues to the ectoderm of the ovum. The sections examined were 20 in number, obtained from various sources. They were digested in a trypsin solution prepared in the usual way from pancreas. Very divergent results were obtained in regard to the degree of resistance to the act,ion of this solution, which was the criterion adopted by the authors above mentioned for the presence of keratin. Investigation showed that these divergencies corresponded with the degree of action of the hardening solutions employed in preparing the tissues for cutting, and that the criterion in questioc is worthless.C. F. C.96 ABSTRACTS OF CHEMICAL PAPERS.A n a 1 y t i c a 1 Chemistry.Apparatus for the Quick Reduction of Measured GasVolumes to Normal Condition. By C. WINKLER (Be?.., 18,2533-2535).-A modification o€ Kreusler's apparatus (Abstr., 1884, 775).New Arrangement of the Volumetric System. By C. WINKLER(Ber., 18, 2527-2533) .-The author thinks that the volumetricsystem should be derived from the molecular weights, and not fromthe equivalent weights, as is the case a t present.A Method of Filtration by Means of easily soluble andeasily volatile Filters. By F. A. GOOCH (Amer. Chem. J., 7,87-90).-Anthracene is proposed as a substitute for asbestos for filteringin cases where the use of paper is objectionable.The anthracene ismoistened with alcohol, then mixed with water, and applied to a per-forated cone or crucible in the same way as asbestos. If necessary, afiner coating, made by dissolving anthracene in hot alcohol and pre-cipitating by water, is afterwards added. .After filtration, the anthra-cene may be removed by treating in a small beaker with warm benzene ;on adding water the benzene solution rises, and may be removedby filtration through a wet filter-paper if thought necessary. Theanthracene may also be removed by gentle heating. H. B.Estimation of Water of Crystallisation in Organic Corn-pounds By E. OSTERHAYER (Chem. Celztr., 1885, 603-604) .-Themethod described by the author is one employed to estimate theamount of water in the salts of iodonaphtholsulphonic acid, which,like many other organic compounds, loses iodine on heating.Aweighed quantity of the salt is heated in a current of dry air in a tubeplaced in an oil-bath a t 110-120" ; the tube is connected with onecontaining a silver spiral, and this with a chloride of calcium tube.The silver is gently heated, and combines with the iodine given off,whilst the water is collected by the calcium chloride, the increase inweight of the latter giving the amount of water.Diphenylamine as a Reagent for Free Chlorine. By H.HAGER (Chem. Centr., 1835, 588).-As a very delicate test for tracesP. P. BANALYTICAL CHEMISTRY. 97of free chlorine, the author nses a solution of diphenylamine in strongsulphuric acid, poured gently down the side of the vessel containiligthe liquid to be t,ested.Should no blue coloration be formed, evenafter standing for a few minutes with subsequent agitation, a smallquantity of pure concentrated sulphuric acid should be added, wheneven very small traces of free chlorine will show themselves bv a bluering forming a t the junction of the two liquids.Naphthol as a Reagent for Free Chlorine and Bromine. BpH. HAGER (Chem. Centr., 1885, 692--693).-A 1 per cent. alcoholicsolution is used ; about; 0.5 C.C. of this is poured gently into a narrowcylinder containing 4-5 C.C. of the liquid to be tested. After standingfor a few minutes, traces of free chlorine or bromine are shown bythe formation of a; milky ring where the two liquids meet.Nitricacid and ferric chloride should be well diluted before apdying thetest. J. K. C.J. K. C.Estimation of Iodine. By G. WEISS (Chem. Centr., 1885, 634,and ?12--713).-The author has lately received samples of iodine,which, when estimated by the ordinary method of titration withhyposulphite, gave over 100 per cent. of iodine. This was found tobe due to the presence of about 3 per cent. of bromine, an impuritydue to the fact that the iodine was obtained from the last mother-liquors in the preparation of nitre, by precipitation as cuprous iodide.The greasy nature of this precipitate renders the complete washingout of the chlorides and bromides present exceedingly uncertain.The author describes a simple method for the quantitative separa-tion of iodine, bromine, and chlorine.The halogens must be presentin the form of simple and easily decomposable metallic compounds.Concentrated ferric sulphate solution is added and the whole boiled,when the following reaction takes place : Fe,(S04)9 + 2KI = 2FeS04 + KZSO, + Iz. During the heat'ing, a current of air is passed throughthe solution, and then into a solution of potassium iodide. When allthe iodine has been carried over int,o this latter, it is removed for titra-tion and replaced by dilute ammonia. After the residue in thedecomposing flask has cooled, a slight excess of potassium perman-ganate is added to it, and the flask warmed to 50-60". Evolutionof bromine soon commences, and the latter is carried over into theammonia by the current of air, and thvn estimat,ed gravimetricdly orby titration. The chlorine can be estimated in the residue, or better,by difference, from a determination of the total quantity of iodine,bromine, and chlorine present in the original substance.If the halogens are present as oxy-acids, they must be reduced bysulphuretted hydrogen o r other suitable means ; if in the free statethey are best converted into zinc iodide by treatment with zinc-dust.L. T.T.Detection and Determination of Fluorine. By G. TAMMANX(Zeit. anal. Chem., 24, 328-343) .-Fresenius' method (Zeit. anal.Chew., 5, 190) of absorbing t,he silicon fluoride by water and weighinggives good results. For destroying admixed carbonates, evaporationwith potash-alum is as effective as boiling with acetic acid.SulphurousVOL. L. 98 ABSTRACTS OF CHEMlOAL PAPERS.anhydride may be arrested by a tube containing chromic acid dissolvedin strong sulphuric acid. This does not retain silicon fluoride;whereas solutions of potassium dichromate and permanganate insulphuric acid, and peroxide of lead as proposed by Kupfer, allabsorb the fluoride.I n substances free from boron, fluorine may be detected by heatingwith quartz powder and sulphuric acid a t 170" in a stream of air,which is then passed through water. As little as 0.0002 gram offluorine yields a ring of silica in the wetted part of the tube. Thewater will then contain hydrofluosilicic acid, besides silica, sulphuricacid and a trace of sulphurous acid.Hydrofluosilicic acid is bestprecipitated by an alcoholic solution of barium bromide or acetate.Barium silicofluoride can be completely washed with 50 per cent.alcohol, 1 litre of which dissolves 0.0257 gram of it. If evaporationbe required, the acetate must be used, since acetic acid does not expelhydrofluosilicic acid, whilst hydrobromic acid does. The acetate~hould be strongly acidified, and the residue must be treated withhydrobrornic acid, to reconvert into silicofluoride any barium fluoridewhich may ha,ve been formed. It is then washed with 75 per cent.alcohol, converted into snlphate and weighed. Test analyses showedthat even in highly dilute solutions, the fluorine can be thus deter-mined without serious loss.Soluble fluorides can be annlysed insimilar manner after conversion into silicofluorides by addition ofhydrobromic acid and silica. The excess of silica is removed byhydrofluoric a d d after the washing with alcohol.Barium silicofluoride may be separated from the sulphate by ignitingthe mixture, and extracting the fluoride of barium by hydrochloricacid.Attempts to determine fluorine in fluorspar and cryolite by the aboveprocesses gave very low results, owing to the fact observed by Landolt,that the action of moist air on silicon fluoride produces an insolublecompound containing fluorine (5-12 per cent.). This body is notdecomposed by evaporation with baryta, but is easiIy solubIe in potash.This led to the following method, which gave good results.To thewater in which the silicon fluoride has been absorbed, an excess ofpotash is added, and the whole evaporated to dryness. The residueis treated with hydrochloric acid, and excess of potassium acetateadded. It is then mixed with 3 vols. of 80 per cent. alcohol, and theprecipitated potassium silicofluoride titrated with potash (Stolba).The same process may be applied without distillation to solublefluorides, adding silica before the acid, but with fluorspar, &c., distilla-tion is necessary.Lastly, the author condemns Wilson's method for estimatingfluorine in organic compounds, and shows that a loss of from 7 t,o asmuch as 68 per cent. of the fluorine may take place during the incinera-tion alone, even when much sodium carbonate or baryta is added.M.J. S.Estimation of Carbon in Iron and Steel. By W. GINTL(BingZ. poZyt. J., 257, 527).-The estimation of carbon in iron,according to Wohler's method-heating in a current cif chlorine andigniting the residue to convert the carbon into carbonic anhydride-iANALYTICAL CELEMlSTRY. 99said to give low results, owing to the difficulty of obtainingchlorine free from oxygen. The author proposes to wash and drythe gas carefully, and pass it over a layer of red-hot charcoal, pre-viously ignited in a current of chlorine before applying it to Wiihler'smethod. D. B.Detection of Thiosulphates i n Water- By G. NEUHUFFER(Chem. Cmty., 16, 459)-Such impurities are to be found in thewater obtained from the neighbourhood of gasworks, and at timesfrom those in the neighbGurhood of vineyards.The presence of thio-sulphates may be ascertained by adding lead acetate to a litre of thewater, collecting the precipitate, washing, and boiling it with sodiumcarbonate solution. The filtmte is evaporated to dryness, and theresidue is tested for thiosulphates by treating it with hydrochloricacid and pure zinc. P. P. B"Ferrous Ammonium Sulphate as a Reagent for Nitric Acid,By A, ROSA (Gazxetta, 15,295-296) .-Ferrous ammonium snlphate isa delicate reagent for the presence of nitric acid ; it is much moresensitive than ferrous sulphate (compare Abstr., 1884, 493).U. H. V.Diphenylarnine and Crystallised Phenol as Reagents forNitrates and Nitrites.By H. HAGEB (Chem. Centr., 183.5, 536-588).-As stock solution, 1 gram of diphenylamine is dissolved in30 C.C. of absolute alcohol and mixed with four or five times its bulkof pure concentrated sulphuric acid. The liquid to be tested ispoured into a test-tube, and the diphenylamine solution allowed torun gently down the side: nitric or nitrous acid in the strengthof one drop of a 30 per cent. solution to 60 C.C. of water is easilydetected by this test, a blue coloration being formed at the pointof contact of the two liquids. The absence of all ohher axidiz-ing or reducing substances must of course be first asoentained. Thatthe blue coloration is not due to chlorine may be ascertained by acontrol experiment with crystallised phenol in hydrucldoric acid : theliquid to be tested is mixed with this in a test-tube, and sulphuricacid poured gently down the side : a, red coloration is.formed by thepresence of nitrogen acids. J. I(. C.Naphthol and Sulphuric Acid as a Reagent for Nitric andNitrous Acids and Free Chlorine. By H. HAGEE (Chem, Centr.,1885, 693-694).-Mix the liquid to be tested with half its bulk of a,1 per cent. alcoholic naphthol solution, and pour sulphuric acid gentlydown the side of the vessel: a brownish-red coloration denotes thepresence of nitrogen acids or free chlorine : if no ring is formed, shakeup, allow t o stand for a few minutes, and pour in gently pure con-centrated sulphuric acid. J. K. C.Arsenic in Bleaching Powder and in Potassium Chlorate.By L.GARNIER (J. Phann. [ 5 ] , 11, 9).-In 1881, Schlagdenhauffen andthe author detected the prssence of arsenic in certain samples ofhiI00 ABSTRACTS OF CHEMICAL PAPERS.bleaching powder. The author reports that recently potassiumchlorate, intended to be used in Fresenius and Babo’s method ofarsenic estimation in organic matter, was found to contain decidedtraces of arsenic. The presence of the metal is ascribed to impurityin the chlorine employed in manufacturing the salt. J. T.Estimation of Arsenic in Ores, Mattes and Metallic Copper.By G. W. LEHMANN and W. MAGER (Amer. Chem. J., 7, 112--113).-R. Pearce’s met(hod (Enyin. Mi%. J., 1883, 256) is found to be themost trustworthy and convenient. The material is fused with nitreand sodium carbonate, and the filtered solution acidified with nitricacid and boiled.Silver nitrate and ammoni:t are added, the pre-cipitate of silver arsenate is washed, and the silver in it estimated byVolhsrd’s method. Metallic copper must be dissolved in nitric acid,and the arsenic precipitated as ferric arsenate by addition of a ferricsalt and ammonia in excess; the precipitate obtained is treated asabove. Satisfactory test analyses are given. H. B.Swedish Method of Testing for Arsenic. By A. ATTERBERG(Chem. Centr., 16, 600-602).-A small portion of the substance istreated in a test-tube with dilute hydrochloric acid, zinc and ferroussulpbate. A plug of cotton-wool moistened with lead acetate isplaced above the mixture, and in the mouth of the test-tube are sus-pended two strips of paper moistened with lead acetate and silvernitrate respectively.If the silver nitrate remains unaltered after12 hours, the substance is declared free from arsenic. If arsenicis found by the above method, then the substance is distilled withhydrochloric acid and ferrous sulphate. A portion of the distillate istested for arsenic as above, and in another portion, the arsenic is pre-cipitated RS sulphide, and metallic arsenic obtained from the sulphideby reduction with potassium cyanide and sodium carbonate in acurrent of carbonic anhydride ; the density of the arsenic mirror de-termining the condemnation, or otherwise, of the goods. The authorproposes to evaporate the distillate with nitric acid: the arsenic isthen obtained in the form of arsenic acid, the presence of which canbe easily recognised by the characteristic reaction with silver nitrate.Eyster’s Scheme for Qualitative Analysis.By R. B. WARDERP. P. B.(Arner. Chem. J., 7, 110-112). Eyster’s scheme is described in Amer.Chem. J., 7, 21-26 ; a modification is here proposed for the detectionof cadmium, copper, nickel, and cobalt : the cadmium is precipitatedby ammonium sulphide in presence of potassium cyanide ; additionof acetic acid to the filtrate throws down the copper as sulphide, andOn adding hydrochloric acid to the filtrate from this, nickel is pre-cipitated as sulphide, whilst the cobalt remains in solution. H. B.Separation of Iron and Aluminium. By M. ILINSPI and G. V.KEORRE (Ber., 18, 2728-2734).-The metals must be present as sul-phates or chlorides, as in the case of nickel and cobalt (this vol.,p.840). The very slightly acid solution is treated with an equal volumeof 50 per cent. acetic acid, and an excess of nitroso-P-naphthol (disANALYTICAL CHEMISTRY. 101solved in 50 per cent. acetic acid), and the whole stirred. After6-8 hours it is filtered, and the precipitated ferrinitrosonaph tho1mashed, first with cold 50 per cent. acetic acid, t'hen with water,dried, ignited with pure oxalic acid, and weighed as Fe203.Ferrircitroso-p-nnphthoz, (CIoHsO-N0)3Fe, forms a voluminousbrownish-black precipitate, soluble in warm moderately dilute hydro-chloric or sulphuric acid ; it is also soluble in glacial acetic acid andin alcohol.Benzene, aniline, and phenol dissolve it with formation ofdark-brown solutions. Warm concentrated potash solution decom-poses it with formation of ferric hydroxide and a green potassiumsalt of nitrosonaphthol.Ferroiiitroso-P-na~hthol is formed when a very dilute solution of aferrous salt is treated with an aqueous solution of nitroso-naphthol :the solution becomes green, and after a long time a separation ofgreen flakes of ferronitrosonaphthol takes place. This compound isvery susceptible towards free mineral acids, and is therefore notformed in a strong solution of ferrous sulphate. N. H. M.Estimation of Manganese. By DEEHL (Chem. Centr., 1885,713-714) .-The author previously recommended the estimation ofmanganese in the presence of iron by precipitation of the mixedoxides, FerOs and MnO,, by hydrogen peroxide, conversion of theseby ignition intoMn,O, and Fe203, and estimation of the iron by titra-tion and of the manganese by difference.He now finds that unlesscarbonates or organic salts of the fixed alkalis are present,, the oldmethod of precipitation of the mixed oxides, Mn,O, and Fe?04, bybromine and ammonia, is as quick, and more exact.Volumetric Estimation of Manganese by Means of Potas-sium Chlorate. By W. HAMPE (Chem. Centr., 1885, 714--715).-1tis well known that potassium chlorate precipibates manganese asperoxide from a boiling solution in concentrated (1.4) nitric acid.The author employs this process in the estimation of manganese inalloys of manganese and iron, &c.The alloy is dissolved in boilingnitric acid, the peroxide precipitated, collected, and titrated. Theresults are very good. The process may also be used for the estima-tion of manganese in ores, &c. The presence of cobalt, lead, andbismuth is injurious, and necessitates a re-solution and second pre-cipitation of the peroxide. Sulphuric and hydrochloric acids, ifpresent, must be removed by barium nitrate or by boiling with nitricacid respectively. L. T. T.L. T. T.Assay of Nickel Coins. By W. C . ROBERTS (Pharm. J. Trans.[3], 15, 1072).-Half a gram of the alloy is dissolved in a smallquantity of nitric acid, 1.5 gram of strong sulphuric acid is added, andthe whole evaporated to dryness. The residue is dissolved, diluted toabout 60 c.c., put int,o a platinum dish which forms the negative elec-trode of an electric circuit, the positive electrode being a flat platinumspiral suspended in the liquid ; the solution should be distinctly acid ;two pint " gravity " cells are sufficient for the deposition of the cop-per, which is complete in 12 hours, when the copper is washed, &c102 ABSTRACTS OF CHEMICAL PAPERS.The solution and washings are heated, made ammoniacal, any pre-cipitated iron removed, and evaporated to about 60 c.c., the solutionis then put into a platinum dish, and electrolysed, using three cells ;the nickel is deposited forming a white, coherent layer.Nitrates mustnot be present except in the smallest possible quantity. D. A. L.Electrolysis of Molybdenum Solutions.By E I?. S b m H andW. S. HOSKINSON (Amer. Chem. J., 7, 90--92).-In a previous paper(Amer. Chem. J., 1, No. 5 ) if was shown that molybdenum could becompletely separated by electrolysis from alkaline molybdic acid solu-tions, but only after a lapse of 100 hours. It, has since been foundthat precipitatisn is complete in two to three hours if the solutionsemployed are faintly acid or neutral. The dense black deposit is inall cases Mo2o3,3H20, and not metallic molybdenum, as stated inthe Handaoorterbuch der Chenzie. A number of very satisfactory teatanalyses are given. H. B.By J. HERZ(Chem. Certtr., 1885, 5'23),-200 C.C. of the beer are acidified withphosphoric acid, and 100 C.C. distilled over ; the amonnt of sulphurousacid in the distillate is finally determined as barium snlphate.Beerbrewed a t the Court Brewery gave by this method from 0.00179 to0.00261 gram SO2 per litre, whilst 0.00373 gram per litre representsthe mean of the results obtained with 84 samples of different beers.In the light of these results, the author would regard as suspiciousany beer which, when treated as above, .yields a distillate giving from5-10 mgrms. of barium sulphate, and if above 10 mgrms. of bariumsulphate there can be no doubt as to the presence of sulphites.Oxidation of Carbohydrates by Means of Chromic Acid.By C. F. CROSS and E. J. BEVAN (Chem. News, 52, 207-208).-Having observed considerable qcantities of carbonic oxide in the gasevolved during the oxidation of cellulose, sugar, &c., by means of amixture of chromic and salphuric acids, the authors have resortedfor quantitative work to a volumetric method, and have successfullyemployed a modification of Schei bler's carbonic anhydride apparatusfor the purpose.The chromic acid is introduced in a small tube intoa small flask connected with the apparatus, and containing the sub-stance mixed with stroug sulphuric acid, the levels are adjusted, andthen the contents of the flask are mixed by inclining and shaking.The authors intend extending the application of this method.Estimation of Uric Acid. By E. LUDWIG (Ghem. Centr., 1885,523).--100 C.C. of the urine are treated with magnesia mixture andan ammoniacal solution of silver nitrate ; in this way a precipitate ofmagnesium silver urate and magnesium ammonium phosphate isobtained.The precipitate is digested with a solution of potassiumsulphide and filtered, the filtrate cont'ains potassium urate, from which,after concentration, the uric acid is precipitated by hydrochloric acid.The uric acid is collected on a filter of glass-wool, freed from sulphurby washing with carbou bisulphide, dried and weighed. If the urineDetermination of Sulphurous Acid in Beer.P. P. B.D. A. LANALYTICAL CHEWISTRY. 103contains albumin this must be first removed by boiling with solution ofsalt and acetic acid, and treating the filtrate as above. The authorfinds the precipitation of uric acid by hydrochloric acid is nevercomplete, even after several days. P.P. B.The Detection of Adulteration. in Oils. By 0. C. S. CARTER(Amer. Chem. J., 7, 92-96).-Cotton-seed oil may be detected whenadded to olive oil or to lard oil, by adding 5 vols. of absolute alcoholand an equal volume of a 1 per cent. solution of silver nitrate inabsolute alcohol ; if cot,ton-seed oil is present, the mixture will rapidlydarken on warming to 84". The presence of much of the drying oils,such as linseed, hemp-seed, or poppy-seed oil, is shown by treatmentwith nitrogen peroxide ; they do not solidify from formation of elaidin.The ease and completeness with which an oil may be saponified is avaluable test ; lard oil saponifies easily ; shark-liver oil and Africanfish oil resist saponification.Detection of Fat Oils in Mineral Oils.By F. Lux (Zeit. anal.Chent., 24, 357--362).--Wben colza oil is heated with potassium,or sodium, or their solid hydroxides, soaps are formed. The higher thetemperature, the more rapid is the saponification. Between 200" and250" the soaps dissolve in the oil, which, on slight cooling, gelatinisesor even solidifies (varying with the alkali used). Mineral oils simi-larly treated do not alter in fluidity. The author tested numerousmixtures of petroleum and lubricating oils with colza, linseed, andolive oils, and found that 2 per cent. of the fat oil in all cases, andper cent. in some, could be detected with certainty by the gelatini-sation which occurred on cooling, after 15 minutes' heating a t 300"with sodium or solid caustic soda. With less than 2 per cent., it isnecessary to heat the test-tube in a paraffin-bath and to avoid agita-tion during both heating and cooling, but with larger proportions ashort boiling over the free flame suffices.Examination of Oils containing Unsaponifiable Fats.By T.MORAWSKI aiid H. DEMSKI (Dinyl. polyt. J., 258, 39-42).-For theestimation of unsaponifiable fats in oils, the authors recommend thefollowing method, having special reference to the difficulty experiencedin completely separating the saponified oil from the unsaponifiablefat. 10 grams of the oil are treated in a flask with -50 C.C. of alcoholand 5 grams of caustic potash dissolved in a small amount of water.The mixture is boiled for half an hour in a reflux apparatus. Theliquid is then diluted with 50 C.C.of water, cooled as ra.pidly aspossible, transferred to a separating funnel, and agitated with lightpetroleurn. The mixture is allowed to settle, the lower layer drawnoff, and the petroleum washed repeatedly with water. To removet'he last particles of water, the petroleum extract is first poured into adry flask and then transferred to a, tared flask from which the petro-leum is expelled by distillation.Test for Adulteration in Butter. By A. WAGNER (Chem. Centr.,2885, 412--413).-This method depends on the fact that naturalH. B.M. J. S.D. B104 ABSTRACTS OF CHERlICAL PAPERS.butter forms an emulsion much more easily t,han other fats. About0.6 gram of butter is put in a flask with 12 C.C. of water and 2 dropsof a 2 per cent.soda solution, and the whole well shaken ; it is thenheated on a water-bath at 37", and transferred to a separating funnel,being washed out with water at the same temperature. From timeto time, the emulsion is allowed to run out, being replaced with waterat 37" until the water becomes quite clear; it is then carefully run out,and after cooling, the walls of the funnel are covered with a finelydivided cheese-like mass if pure butter has been operated'upon, butthe presence of any other fat is made apparent by oily drops whichare visible also during the previous process. J. K. C.Critical and Experimental Study of the Knop - HiifnerMethod of determining Urea. By C. JACOBJ (Zeit. anaZ. Chern.,24, 307-328).-The author defends the hypobromite process againstthe objections of Arnold (Bbstr., 1883, 1141), and maintains that ifthe operation be carried out in a uniform way, the use of an empiricalconstant for calculabing the nitrogen into urea will always givesatisfactory results.Hufner by using 5 C.C. of a 1 per cent. urea solu-tion and 100 C.C. of Knop's original bypobromite reagent, obtained354.3 C.C. of nitrogen (at 0" and 760 mm.) from 1 gram of urea.Using this constant, the author made a series of determiuations withpure urea solutions, varying in strength from 0.666 to 3.0 per cent.by both the Liebig-Pfluger and the Knop-Hiifner methods, and foundthat the latter gave on the whole the smaller errors. These were inalmost all cases errors of deficit, and the deficiency increased some-what-though not proportionally-with the strength of the ureasolution, whilst Liebig's method gave more irregular results, some-times much above the truth.With normal urine, and also with thatof fever patients, Liebig's method invariably gave higher numbersthan Hufner's, the difference being greatest with the pathologicalurine. With diabetic urine, containing 3 or 4 per cent. of sugar,Hufner's method still gave the lower numbers, but with a specimencontaining 6 per cent., the use of the constant 354.3 led to a resulthigher than that yielded by Liebig's process. Determinations byboth methods in solutions of pure urea, to which varying quantitiesof grape-sugar had been added, showed that the amount of nitrogenliberated increases with increasing quantities of sugar, although withas much as 6 per cent.it did not reach its theoretical limit. Sub-stituting f o r the sugar 1 to 5 per cent. of ethylic acetoacetate (thepresence of which in diabetic urine has been suspected), practicallythe theoretical quantity of nitrogen was obtained, instead of the usualdeficiency of 8 per cent., and with healthy urine, to which 1 per cent.of the ether had been added, the use of the theoretical constant 371.4gave approximately the same results as the use of 354.3 in the ab-sence of the ether. Liebig's method gave higher results, supportingthe view that mercuric nitrate precipitates other substances fromurine besides urea. The author recommends that 4 per cent. of theether should be added to diabetic urine, and the constant 371.4 usedin the calculation.Finally it is argued that the results of this method are affecteANALYTICAL CHEMISTRY.105only to an insignificant extent by the other nitrogenous constituentsof urine, except albumin and ammonia salts, of which the former iseasily removed, and the latter, even if it be not right to calculate itas urea (which is almost certainly formed in the system by the de-hydration of ammonium carbonate), can be determined by Schlosing'sor Schmiedeberg's method, and allowed for. M. J. S.Presence of Glutamine in Sugar-beet. By E. SCHULZE andE. BOSSHARD (Landw. Versuchs-Xtat., 1885, 129--136).-1n a previouscommunicat,ion (Abstr., 1885, 658), the authors have shown thatglutaminc can be precipitated by means of mercuric nitrate from thejuice of sugar-beet ; Scheibler has also obtained glutamic acid frombeet molasses. In this paper the method employed to precipitate andestimate the glutamine in the crude juice is described; the quantity(1 gram per litre) obtained by this process is far below that which isreally present (5.96 grams per litre) ; the difference is due to theimperfect precipitation, &c.It is this glutaminc which, after boiling,is converted into the glutamic acid detected by Scheibler.Estimation of Alkaloids in the Leaves of Atropa Bella-donna. By W. R. DUNSTAN and P. RANSOM (Pharm. J. Tyans. [3],16, 237-238).--20 grams of dried and finely-powdered leaves areexhausted with about 100 C.C. of absolute alcohol. The alcoholicliquid is diluted with about an equal volume of water slightly acidifiedwith hydrochloric acid, warmed and extracted with chloroform toremove chlorophyll, fat, &c. The aqueous residue is rendered alkalinewith ammonia and again extracted with chloroform. The chloroformsolution on evaporation leaves a residue of the pure alkaloid which isdried at 100" and weighed. Foreign leaves have been found to con-tain 0.22 per cent. total alkaloid, and English leaves overheated indrying 0.15 per cent.E. W. P.D. A. L.Sulpho-conjugate Colouring Matter in Wines. By CARLES(J. Phscrm. [5], 11, 109--110).-The author finds that the methodrecommended for the detection of these colouring matters in wine isnot generally applicable. It consists in removing sulphates by meansof barium chloride, removing the barium salt by means of an alkalinecarbonate, then evaporatirig and calcining the residue ; sulphates thusproduced are supposed to indicate the artificial colouring matters jnquestion. Erroneous results were obtained not only with winesknown to be pure non-plastered, but also with wines made by theauthor from choice grapes in glass vessels (1) without any addition,( 2 ) plastered with sulphurous gelatin. J. T.By W.CHLUDINSKY (Landw. Versuchs-Stat., 1885, 117--128).-The authordescribes his method of estimating the composition of fleeces, andenters into considerable detail concerning the apparatus (Eurianalyser)which he has designed for the removal of the grease by means ofcarbon bisulphide. As regards the composition of various wools, it isstated that the hygroscopic properties of different wools are almostComposition of Long-wool and Merino Fleeces106 ABSTRACTS OF CHEMICAL PAPERS.identical ; merino fleeces have less impurity in them than other fleeces,but are richer in insoluble suint ; of other than merinos, Southdownfleeces are most largely contaminated with impurities, whilst thehighest percentage of pure wools is found in fleeces from short-tailedsheep. E. W. P.Diagnosis of Keratin in Animal Tissues. By H. STEINBREGGE(Zeit. Biol., 21, 631--635).-The author has applied Ewald andKuhne’s method (Verh. Med. Vereins z. Beidelberg, 1, 4.51) to theinvestigation of the tissues of the ear of mammalia for the presenceof keratine as a normal constituent, which was a probability to beinferred from the morphological relationship of the tissues to theectoderm of the ovum. The sections examined were 20 in number,obtained from various sources. They were digested in a trypsinsolution prepared in the usual way from pancreas. Very divergentresults were obtained in regard to the degree of resistance to theact,ion of this solution, which was the criterion adopted by the authorsabove mentioned for the presence of keratin. Investigation showedthat these divergencies corresponded with the degree of action of thehardening solutions employed in preparing the tissues for cutting,and that the criterion in questioc is worthless. C. F. C