FOOD AND DRUGS ANALYSIS 399 ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOOD AND DRUGS ANALYSIS. Estimation of the Amino-Acids in Feeding-Stuffs by the Van Slyke Method. H. S. Grindley, W. E. Joseph, and M. E. Slater. (J: Awr. Chem. Sot., 1915, 37, 1778-1781.)-The following quantities of amino-acid nitrogen were found in various feeding-stuffs, the Van Slyke method (ANALYST, 1911, 36, 457) being used for the estimations; the results are expressed as percentages of the feeding-stuff: Cottonseed Meal.-As ammonia, 0.702 ; melanine, 0.522 ; arginine, 1.311 ; cystine, 0.043 ; histidine, 0.367 ; lysine, 0.321 ; amino-nitrogen in filtrate from bases, 2.876 ; non-amino-nitrogen, 0.365 ; total nitrogen, 6.507.Tankage.-As ammonia, 0,659 ; melanine, 0.440 ; arginine, 1.416 ; cystine, 0,128 ; histidine, 04951 lysine, 0.749 ; amino-nitrogen in filtrate from bases, 5.238 ; non-amino-nitrogen, 0.729 ; total nitrogen, 9.851.AZfava Hay.-As ammonia, 0.222 ; melanine, 0.415 ; arginine, 0.202 ; cystine, 0.019 ; histidine, 0.196 ; lysine, 0.108 ; amino-nitrogen in filtrate from bases, 1.157 ; non-amino-nitrogen, 0.267 ; total nitrogen, 2.573. w. P. 8.Estimation of Fat. H. Rosenthal and P. F. Trowbridge. (Amer. J. Pharm., 1915, 87, 309-315.)-While a simple extraction of the fat with ether in a Soxhlet extractor gave concordani; results in the estimation of fat in pork, the results were variable and unreliable in the case of blood and liver. To obviate the extraction of substances other than fat the following method is suggested : The sample is heated with occasional stirring for two hours on the water-bath with 30 C.C.of 20 per cent. sodium hydroxide solution. The warm saponified solution is transferred to a separating funnel, mixed with 35 C.C. of 20 per cent. hydrochloric acid (sp. gr. 1-l), and when cold shaken with ether. The ethereal extracts are united, and evaporated to dryness, and the residue dissolved in about 25 C.C. petroleum spirit (boiling-point 30' to 50' C.), treated with 15 C.C.of 95 per cent. alcohol, and titrated with zV alkaline solution, with phenolphthalein as indicator. I n converting the fatty acids into neutral fat the factor 1.045 is used. C. A. M. Composition of Extraeted Olive Oils Purified by Esterification. F. Can- zoneri. (AnnaZi Chirn. AppZic., 1915, 3, 344-349.)-0live oils which have been extracted with carbon disulphide are now neutralised and decolorised by a, patent process of esterification.The resulting products have a pleasant odour, and are completely saponifiable. They are soluble in alcohol, ether, and carbon disulphide, and rapidly oxidise to form viscous liquids. A sample prepared from an olive oil with an acidity of 22 per cent.(as oleic acid) had the following characters : Sp. gr. 09055 ; refractometer reading (Zeiss), 51.5 ; iodine value, 75.20; Maumenb test, 40' C.; and viscosity (Engler), 5.8. Another sample, prepared from an olive oil with 50 per cent. of free acid, had a sp. gr. of 0.901; iodine value, 73; and viscosity of 4.5. I t s approximate composition was as follows : Esters of fixed fatty400 ABSTRACTS OF CHEMICAL PAPERS acids (mainly oleic acid), 51; esters of volatile fatty acids, 2 ; glycerides, 37; free acids (as oleic acid), 5 ; hydroxystearic acid, 3 ; and stearolactone, 2 per cent.C. A. M. Constants of the Fatty Acids from Sulphonated Cod Oil. L. G. Radcliffe and C. W. Palmer. (J. SOC. Chem. Ind., 1915, 34, 643.)-The constants of the fatty acids prepared from a brown cod oil, and of those obtained after the oil had been sulphonated, are given below.The sulphonation was carried out by gradually adding 35 grms. of concentrated sulphuric acid to 100 grms. of the oil, the mixture being cooled externally so that the temperature did not rise above 25" C. After two hours' stirring, the darkened and thickened product was washed with cold saturated sodium sulphate solution until nearly all the free sulphuric acid had been removed, and the fatty acids were then separated : Fatty Acids from Fatty Acids from Original Oil.Sulphonated Oil. Solidifying-point (titre test) . . . 22.8' C. 25.7" C. Neutralisation value . . . ... 194 183 Mean molecular weight ... ... 289.4 308.6 Iodine value ... ...... 178 114.4 Yield of hexabromides ... ... 42 per cent. 11 per cent. w. P. s. Analysis of Guara and Guara Extract. T. Callan. (J. Sot. C k m . 1915, 34, 645-646.)-Guara is a newly-introduced tanning material consisting of the ground fruits of a variety of divi native to South and Central America, freed from seeds and woody husks. The most distinctive features in the microscopical appearance of the substance are the small brown plates showing a honeycomb structure and small brown plates furnished with needle-shaped hairs.A dilute aqueous infusion of guara, gkws a violet-blue coloration with iron alum, no precipitate with bromine water, no phloroglucinol reaction with a deal shaving, a yellow precipitate turning green with lime-water, a slight precipitate with formaldehyde and hydrochloric acid, a yellow coloration with sodium sulphite, an intense red coloration with very dilute ammoniacal potassium ferricyanide solution, and a deep orange-brown coloration with nitrous acid.Analyses of numerous samples show that guara contains: Moisture, 9.0 to 10.7 per cent. ; tannins, 43-5 to 48.4 per cent. ; non-tannins, 23.1 to 25.8 per cent.; insoluble substances, 19.0 to 22.0 per cent.Skins tanned with guara give a soft, well-filled leather, resembling a gambier tannage rather than a sumach or myrobalan tannage. A sample of solid guara extract examined contained : Moisture, 17.3 per cent. ; tannins, 41.7 per cent. ; non-tannins, 30.0 per cent. ; insoluble substances, 11.0 per cent. I n use the extract has proved to be inferior to the natural product.w. P. s. Group Method for the Detection of Gelatinising Agents, Pasty Material, and Thickeners used in Food Products. L. A. Congdon. (J. Ind. and Eng. Chem., 1915,7,606-607.)-Many thickening materials are used to cover up inferiority in food products. Albumen or white of egg is sometimes used to glaze coffee beans.FOOD AND DRUGS ANALYSIS 401 Agar-agar has been found in imitation lemon slices ; starch, agar-agar, and gelatins in imitation jelly ; dextrin in imitation cocoa tubes; ice-cream powders, used in ice cream and custards, employed to add bulk to the product and to give the material in which they are used a frothy appearance, may contain one or more of the following : Dextrin, gum acacia, gum tragacanth, gelatin, albumen, and starch.The following scheme has been set out, which will lead to the identification of any or all of these materials : Groups. Group I. .. Group 11. .., Group 111. . . . Group IV. . .. Group V. ... Group VI. , . . Group Reagents. Iodine solution ..( Millon’s or Stokes’s r e a g e n t ( a c i d nitrate of mercury) Zoncentrated solution of sodium borate Solution of sodium hydroxide Solution of mercuric chloride Schweitzer’s reagent (solution of cupra- ammonia) Reactions with Water-Soluble Solutions of the Gelatinising Agents, Pasty Materials and Thickeners. Blue coloration indicates starch.(Sometimes green apples made into jelly will give traces of starch.) Purple coloration indicates amylo-dextrin. Red coloration indicates erythro-dextrin.No coloration may suggest the presence of achro-dex trin. Mixture, after shaking substance in solution with reagent, is cloudy. Yellow preoipitate with picric acid solution indicates gelatin. Drop of this reagent : Gelatinous precipitate, soluble in excess of this reagent, indicates gum acacia. A slight white precipitate may indicate either agar-agar or gum tragacanth or both (test for tragacanth as in Group IV.).A white gelatinous preoipitate indicates either agar-agar or gum acacia or both. Gum acacia will give a gelatinous opaque white precipitate with basic lead acetate. Gum acacia may be further tested for as in Group 11. or Group IV., or by adding a solution of tannin, which produces a bluish- black coloration. A brownish yellow colour on heating indicates gum tragacanth.A white cloudy precipitate indicates gum acacia. A slight turbidity may indicate dextrin. A white precipitate may indicate albumen and gelatin. If a concentrated aqueous solution of the material to be tested is treated with this reagent and placed on a glass slide under a microscope, a delicate framework of cupric pectate is evident, showing a pectin of fruit or vegetable origin present.H. F. E. H.402 ABSTRACTS OF CHEMICAL PAPEES New Method for the Estimation of Hydrocyanic Acid and Benzaldehyde in Kirsch. J. Golse. (J. Pharm. Chim., 1915, 12, 44-56.)-The French official method for the estimation of hydrocyanic acid and benzaldehyde in cherry liqueurs leads to seriously inaccurate results, The two constituents are separated by dis- tilling the liqueur previously made slightly alkaline in order to fix the hydrocyanic acid.I t is proved, however, that sodium cyanide is only stable on distillation in presence of a large excess of sodium hydroxide, and it is necessary to add to 200 C.C. of kirsch at least 10 C.C. of caustic soda lye, sp. gr. 1-32 to 1-36, Further, the dis- tillation of the benzaldehyde is not complete with the collection of 125 c .~ . of distillate, and the precipitation of the hydrazone often fails in presence of the quantity of alcohol commonly found in kirsch distillates. In investigating this matter it was noted that, in the case of cherry-laurel water, an accurate separation could be obtained by employing the large excess of alkali above mentioned and collecting 175 C.C.of distillate, but in the case of kirsch the secondary effects of the, alkali, accompanied by violent frothing, make the method not readily practicable. An alternative method, based on the fixation of the benzaldehyde by phenylhydrazine and distillation of the hydrocyanic acid, was also successful with cherry-laurel water, but failed with kirsch on account of the existence of a portion of the acid in the form of non-volatile combination.Finally, the following procedure was adopted: 200 C.C. of kirsch are placed with 1 C.C. of caustic soda lye in a flask of 500 C.C. capacity carrying a dropping funnel extending below the surface of the liquid and a tube leading to a condenser, 1 metre long. Distiliation is carried out very slowly on account of frothing, and 175 C.C. of distillate are collected, The contents of the flask are cooled, and the point of the condenser is caused to dip into a gauged flask of 55 C.C.containing 5 C.C. of ammonia, ; 50 C.C. of sulphuric acid (1 : 10) is then slowly added through the dropping funnel, and distillation is continued until 50 C.C. of distillate have been collected separately. The 175 C.C.of distillate first obtained is treated with 5 C.C. of phenyl- hydrszine reagent (10 grms. of sodium acetate, 5 C.C. of glacial acetic acid, 100 C.C. of water, 1 C.C. of phenylhydrazine, and 1 C.C. of sodium bisulphite solution), and its volume made up to 200 C.C. This liquid is redistilled, the firat 75 C.C. of distillate, containing hydrocyanic acid, being added to the 50 C.C.previously collected, and a further quantity, ranging from 50 to 75 c.c., according to the alcohol-content of the kirsch, is distilled off. Without removing the condenser, a water-bath is then sub- stituted for the Bunsen burner, and the poiht of the condenser is closed with a rubber tube and clip to exclude the air. The contents of the flask are digested in the water-bath for two hours, until the precipitate of hydrazone has settled.After cooling, the hydrazone is collected on a filter, washed, and dissolved on the filter first with 10 C.C. of alcohol, then twice with 10 C.C. of ether. The solution is collected in a tared glass dish, evaporated, and the hydrazone dried in vacuo and weighed ; the weight x 2.7 gives the benzaldehyde per litre. The distillate con- taining the hydrocyanic acid is treated with 1 C.C.of 10 per cent. potassium iodide solution, and titrated with & silver nitrate, until a permanent opalescence is formed ; the number of C.C. used x 13.5 gives the mgrms. of hydrocyanic acid per litre. Analyses of authentic samples of kirsch showed from 17.6 to 35.8 mgrms. of hydro-FOOD AND DRUGS ANALYSIS 403 cyanic acid per litre and 29.7 to 37.3 mgrms.of benzaldehyde, while specimens, probably sophisticated, showed from 52.9 to 108 mgrms. of the latter per litre. J. F. E. Estimation of Lint in Cottonseed Meal. R. N. Braekett. ( J . I d . and Eng. Chem., 1915, 7, 611, 612.)-Alkali and acid of 1-25 per cent. strength as used for crude fibre estimations are practically without action on lint.A portion of cotton- seed was carefully freed from lint, the seeds were then cut open, and the interior of the seeds was completely separated from the hulls. Crude fibre was then prepared from both the hulls, and the seed interiors, and the material thus obtained was treated in 0.2 grm. portions side by side with the same weight of lint, on a boiling water bath with 25 C.C.of a solution of zinc chloride for three minutes, the time required to dissolve the lint. The zinc chloride solution was prepared by dissolving metallic zinc in concentrated hydrochloric acid, concentrating until the solution solidified on cooling, and then adding twice the weight of 40 per cent. hydrochloric acid. On treating the crude fibre and lint with the zinc solution, the contents of the beakers were stirred vigorously during the three minutes necessary to dissolve the lint, and filtered hot through weighed porcelain Gooch crucibles with asbestos mats; the residues in the case of the fibres were washed with 25 C.C.of the zinc solution, then with water, and finally with 95 per cent. alcohol. Test mixtures of known composition showed an error of about 0.5 per cent., calculated on the weight of lint present in the mixture.H. F, E. H. Volumetric Estimation of Sulphurous Acid in Wines. L. Ferr6. ( A m . Chim. anal., 1915, 20.)-A measured quantity (100 c.c.) of the wine is acidified with 2 C.C. of syrupy phosphoric acid, and gently boiled for thirty minutes in a flask con- nected with absorption vessels, one containing 40 C.C. of iodine solution (3.968 grms. per litre, 1 c.c.=O*OOl grm. of SO,), and the other 5 C.C. of sodium thiosulphate solution (7.740 grms. per litre, 1 C.C. =0.001 grm. SO,). The thiosulphate solution in the second vessel is then added to the iodine solution in the first vessel, and the mixture titrated with more of the thiosulphate solution. Combined sulphurous acid is estimated by adding to 100 C.C. of the wine the number of C.C. of iodine solution required to oxidise the total sulphurous acid, as found in the first estimation. Sufficient standard sodium arsenate solution to destroy all the iodine, if no free sulphurous acid were present, is then added, and the estimation continued as in the case of total sulphurous acid. C. A. M.