BACTERIOLOGICAL, PHYSIOLOGICAL, ETC. 381 ORGANIC ANALYSIS. Detection of Arachidic Acid. R. H. Kerr. ( J . Ind. and Eng. Chmn., 1916, 8,904.)-The following method is simpler than Renard’s official method, and obviates the use of ether: Twenty grms. of the oil are heated with 200 C.C. of 95 per cent.382 ABSTRACTS OF CHEMICAL PAPERS alcohol in a 300 C.C. Erlenmeyer flask, and 10 C.C. of 10 per cent.potassium hydroxide are added to the boiling liquid. After saponification of the oil the excess of alkali is neutralised with a solution of 50 C.C. of glacial acetic acid in 150 C.C. of 95 per cent. alcohol, and 5 C.C. of a 5 per cent. solution of magnesium acetate in a mixture of equal volumes of water and 95 per cent. alcohol are added. The flask is cooled, with_foccasional shaking, and then left in a refrigerator a t 10" to 12" C.until the next day. The precipitate is filtered off, washed twice with 50 per cent. alcohol and three times with water, and returned to the flask. It is then treated with 100 C.C. of hot water and sufficient dilute sulphuric acid (50 : 150 c.c.) to deconipose the magnesium salts, and heated until the fatty acids form a clear layer.After solidification, these are washed with hot water, again left to solidify, drained from water, and dissolved in 100 C.C. of 90 per cent. (by volume) alcohol. The arachidic acid which crystallises is separated by the method of the Ass. Off. Agric. Chemists (Bull. 170, Revised, Bureau of Chemistry, p. 146). The method gives results as good as those obtained by Renard's method, and is capable of detecting 5 per cent.of arachis oil in olive oil, cottonseed oil, soya-bean oil and niaize oil. C. A. M. Estimation of Carbohydrates-V.: The Supposed Precipitation of Reducing Sugars by Basic Lead Acetate. W. A. Davis. (J. Agric. Xci., 1916, 8, 7.)- Since Gill (J. Chem. Xoc., 1871, 24, 91) observed that the addition of an excess of basic lead acetate to a solution of invert sugar reduced the negative rotation of the !m-u!ose owing t o the fmiliaticjii of a soluble co~npou~ici, rriany workers 'nave assumed that this sugar is precipitated by the defecating agent to a greater or less degree.The author shows that, a t least in dilute solutions, lzvulose is never precipitated by basic lead acetate even in presence of salts such as chlorides, sulphides, or carbonates.No loss of lzvulose occurs unless the excess of lead is allowed to act for some length of time upon the sugar before the lead is precipitated. Thus, if basic lead acetate is left with a solution of pure lzvulose for periods of time such as fifteen minutes, one hour, or twenty-four hours, and the lead is then precipitated by sodium em- bonate or sulphate, amounts of laevulose are found to have disappeared, depending solely on the time of action, the solution becoming more and more yellow, but no visible separation of lzvulose occurs. It is probable under these conditions that a substance resembling or identical with the so-called glutose of Lobry de Bruyn and van Ekenstein (Rec.Trav. Chim., 1897, 16, 262) is formed, having little or no optical activity and a reducing power about one-half that of dextrose.It is shown that, provided basic lead acetate solution is added in small quantities a t a time until precipitation is just complete, and that the excess is not allowed to reach more than about 5 C.C. in 300 to 500 of sugar solution, there is no loss whatever of reducing sugar. The excess of lead should be removed with sodium carbonate or sulphate as boon as possible after filtering off the precipitate.Dextrose and maltose remain practically unchanged in presence of a considerable excess of basic lead acetate, although eventually even with these sugars soluble lead compounds having a different optical activity may be formed (4. Watts and Tempany, ANALYST, 1908, X3, 130; Eynon, ibid., 1909, 34, 349).H. F. E. H.ORGANIC ANALYSIS 383 Analysis of Crude Calcium Cyanamide. E. Truninger. (Schzueiz. ver. anal. Chem., May 26 and 27, 1916.)-A slight alteration is to be made in the method previously dekcribed : the cyanamide should be precipitated with neutral silver nitrate and the ammonia added afterwards. For the present, the dicyandi- amide may be determined indirectly by the simultaneous precipitation of cyanamide and dicyandiamide with silver nitrate and 2 per cent, potassium hydroxide solution, and subsequent determination of the nitrogen in the precipitate by Kjeldahl's method.The determination of urea has not been deeply studied because it is not yet certain whether that substance is present. Caro's method (ANALYST, 1916, 36, 76) could not give accurat'e results, because the prolonged heating with alkali to drive off the ammonia would cause losses not only of dicyandiamide, but also of urea if present.Determinations of the insoluble nitrogen in the residue from the extraction of the crude material with water, and dilute nitric acid showed an average of 1 per cent.: in a few cases 2 per cent.was found. Agricultural experi- ments with calcium cyanamide on oats confirmed its favourable effects; with the exception of a single sample rich in dicyandiamide, an increased yield was recorded. The injurious influence of considerable quantities of this substance was shown a t an early stage, but could be largely inhibited by the simultaneous application of a readily assimilable nit'rogen compound.I n considering the unfavourable influence of the dicyandiamide, its great stability in the soil must be taken into account; nitrification had not taken place after a period of two months. Secondary ill-effects were observed in the case of oats even in the ~eccjfid year; or, the ot'her hand, calcium cyanamide which had lain for a long time on the moist ground had lost much of its valuable properties.Vegetation experiments with urea and urea nitrate showed excellent results with oats. With winter wheat a top dressing of calcium cyanamide and urea showed the great value of urea used in this form. Casein and its Technical Applications. D. Marotta. (Annali China. AppZic., 1916, 6, 165-176.)-Pure casein has a sp. gr. of 1.259. When dried in the air a t 70" to 80" C.for five hours it loses 5 to 8 per cent. in weight, while when dried in vacuo it retains 2 per cent. of moisture. It is readily soluble in 1 per cent. Eolutions of sodium fluoride, ammonium oxalate, and potassium oxalate, and in 5 per cent. solutions of ammonium chloride or sulphate. It ought to be free from Eoluble salts, lactose, or peptones, and should yield less than 1 per cent.of ash on ignition. Technical casein is yellowish, and yields up to 6 per cent'. of ash. It contains 12 t o 13 per cent. of water, 12 t o 13 per cent. of nitrogen, and about 0.5 per cent. of fat. When prepared by the action of acids, it is soluble in solutions of alkalis and sodium salts of the following strengths : Sodium hydroxide, 2.0; carbonate, 2.5; bicarbonate, 3; silicate, 10; arsenate, 20; sulphite, 9; tungstate, 12.5; borate, L:-5: and ammonia 2.5 per cent.The casein obtained by the action of rennet is in~oluble in solutions of sodium carbonate and bicarbonate, partially soluble in borax and ammonia solutions, and soluble in sodium phosphate Eolution. Of the pharnia- ceutical preparations of casein, perriodo-cas&n contains 17.89 ; iodo-casein, 1 5 7 ; and caseo-iodine, 8.7 per cent.of iodine. A casein still richer in iodine (21.6 per cent.) is prepared by adding iodine to milk and precipitating the compound with acetic354 A BS'l'RACTd OF CHEMICAL PAPERS acid. The Zacfo-iodine-periodine of commerce contains 5.7 per cent. of iodine. Pre- parations of bromo-casein contain from 4.5 to 11 per cent.of bromine. There is also a chlorine preparation wit'h 2.8 per cent. of chlorine, and a Fuoro-ca.sein con- taining 1.6 to 1.8 per cent. af fluorine. Xilver caseinate contains 80'16 to 9.66 per cent. of silver, and there are also preparations containing 4, 10, and 15 per cent. The compound " argonine," which is prepared by treating sodium caseinate with silver nitrate and precipitating the compound with alcohol, contains 4.2 per cent.of silver. Another commercial product, " argonine L," contains 10 per cent. of silver. Coiiipouiids of casein with alkaloids are prepared by suspending the casein in alcohol and editing an alcoholic solution of the alkaloid. Iron caseinate contains 3-6 per cent. of iron. C. A. M. Comparison of Barbituric Acid, Thiobarbituric Acid, and Malonylguani- dine as Quantitative Precipitants for Furfural.A. W. Dox and G. B. Plai- sanee. ( J . Amer. Chem. Xoc., 1916, 38, 2156-2166.)--Unger and Jiiger (Ber., 1902, 35, 4440, aiid 1903, 36, 1222) applied the reaction between barbituric acid and furfural to the quantitative estiination of the latter, but a large excess of the acid appears to be necessary for conipjete precipitation although the reagent has the advantage of not precipitating hydroxymethyl furfural.The authors found that for various reasons thiobarbituric acid-CH?(CO),(~~),CS-is much the better reagent t o use, and this was prepared according to the method of Fisher and Dil- threy (AWN., 1904, 335, 350), in which twice thg themetical a:~,=unt ~f sediurn dis- solved in a little alcohol is mixed with 16 grms.of iualonic ester and '7.6 grms. dry thiourea previously dissolved in absolute alcohol. The mixture is heated for fifteen hours in a closed tube a t 105" C., and the product, after acidifying with hydrochloric acid, separates as a slightly yellowish crystalline powder cont aiiiiiig 19.6 per cent. of nitrogen. The yield is 45 per cent. of theory.The precipitation of the furfural is carried out in 12 per cent. hydrochloric acid solution at room teiiiperature in a total volume of 400 c.c., using slight excess of the thiobarbituric acid exactly as in the case of phloroglucinol, and after being allowed to stand overnight the precipitate is filtered off and dried till constant a t 100" C. I n the case of malonylguanidine, the condensation of furfural is not quantitative, the best results being 50 per cent.in error, while with barbituric acid only 95 per cent. of the furfural taken is re- covered when using about 60 ingrins. of furfural, while with small amounts of fur- furel (12 to 35 mgrms.), only from 25 to 80 per cent. is recovered. With thiobar- bituric acid, however, the theoretical weight of precipitate is obtained working on quantities of furfural varying froin 11 to 60 mgrms.Variations in the amount of precipitant were of little influence. The subst aiice formed-furfuralinalonyl- thiourea (C, H,O,N,S) is a bright yellow precipitate, very flocciilent and voluminous, practically insoluble in cold dilute acids, alcohol, ether, petroleuin ether, methyl alcohol, acetic acid, benzene, carbon disulphide, and turpentine.In ammonia, pyridine, and caustic alkalis it dissolves readily, giring a greenish-blue solution which gradually loses its colour. It is essential that the thiobarbituric acid em- ployed should be strictly pure and free from dicyandiacetylthiourea, or error will be introduced, and it is recommended that the malonic ester used for its prepara-ORGANIC ANALY81S 385 tions shoitlcl be subjected to a repetition of the siniultaneous saponification and esterification before condensation with thiourea, and that the thiobarbitnric acid itself be purified by one or two crystallisations of its sodium salt.The authors do not find that any reliance can be placed upon the separation recommended by Ishida and Tollens ( J .Landzc., 1911, 60) for the separation of the phloroglucides of furfural and methyl furfural based on the solubility of the latter in alcohol. Since methyl furfural is also precipitated by thiobarbituric acid, evidence can only ke obtained of its presence bj- analysis of the condensation product, which in the care of the methyl salt contains nitrogen 11.86 per cent.and sulphur 13-56 per cent., as against the 12.6 and 14-41 in the furfural compound. The author considers that such an analysis would show the presence of methyl furfural if present to the extent of 1 in 3 of furfural; but where the ratio is less, the lowering of the nitrogen would be within the limits of analytical error. H. F. E. H. Benzoyldihydromethylketol Hydrazine.New Reagent for Galactose. J. von Braun. (Ber., 1916, 49, 1266-1268; through J . Xoc. Chem. Ind., 1916.)- Benzoyldihyclromet hylketol hydrazine, is a specific reagent for galactose, with solutions of which it gives a colourless cry- stalline precipitate in froin half to two hours according to the concentration. With dextrose, laevulose, mannose, arabinose, and xyloee no precipitate is produced.The base is prepared froiii beiizoyldihydromethylketol, which is nitrated and reduced t o m-amino-K-benzoplclihydromethylketol. This is diazot'ised and reduced with stannous chloride, a i d the hydrazine isolated in the usual way. It crystallises from alcohol in colourless needles (m.-pt. 150-151" C.), and is apparent,ly quite stable when dry. The h5-drochloride melts at 195" C'., and the semicarbazide derivative at 213" C.Highly Unsaturated Hydrocarbon in Shark Liver Oil. M. Tsujimoto. (J. Ind. and Eng. Chem., 1916, 8, 889-896.)-Ai-zami oil, extracted from the liver of the Japanese squaloid shark, Xqualus mitsukurii, gave the following analytical values: Sp. gr. at 13"/4' C., 0*8644; solidification point, below - 20" C. ; acid value, 0; saponification value, 22.98 ; iodine value (Wijs), 344.63 ; f n ] ~ 200 c , 4930. qatty acids (10.62 per cent.) : Pu'eutralisation value, 168.52; iodine value, 119.25.Glycerol, 0.52 per cent. ; and unsapoiiifiable matter, 9O*l'i per cent. Heratsuno-xamh oil from the liver of another sqaaloid shark, Deania eglantina, gave the following values: Sp. gr. a t 15"/4" C., 0*8'721; acid value, 0.49; saponification value, 52.46; iodine value (Wijs), 261.72; [ n ] ~ 20 c., 1.4850.Fatty acids (26.59 per cent.) : Neutralisation value, 168.39; iodine value, 7335. Glycerol, 0.39 per cent. ; and unsaponifiable matter, 72-88 per cent. In each case the unsaponifiable matter, after deducting the cholesterol (0.65 and 1.24 per cent. respectively), consisted mainly of a hydrocarbon or hydro- carbons, which could be separated by shaking the saponified oils with petroleum spirit. It was a colourless oily liquid and had the composition Cf0H,,, and showed386 ABSTRACTS OF CHEMICAL PAPERS the following charasters : Boiling-point, 262' to 264" C. (10 iiini. pressure) ; solidifica- tion point, - 55" C. ; sp. gr. a t 15"/4" C., 0.8587; iodine value, 388.12 (Wijs) ; [ n ] ~ Z O C O . , 1-4965. It dried rapidly, yielding a colourless film superior to that formed by vegetable drying oils. It formed an addition compound with bromine, C,oH,oBr,, . The hydrogenated product, C,,HBZ, resembled the so-called liquid paraffins, but was more stable in the cold. It could be used for lubricating machinery. C. A. M.