312 EXPEEIMENT STATION EECOED. fVol. 37 



The amino-acid nitrogen was determined by Van Slyke's gasometric procedure 

 and by Sorensen's formol titration method, and the reducing substances by 

 Benedict's quantitative method for sugar. 



It is indicated that, "as is the case with all perishable substances, decompo- 

 sition in oysters is not prevented by low temperatures but is merely retarded, 

 especially at temperatures near the freezing point." 



The determ.iiiation of peanut oil in mixtures with olive oil, R. Biazzo and 

 S. ViGDOBCiK (Ann. Chim. Appl. [Rome], 6 {1916), No. 9-12, pp. 179-185). — 

 Methods which have been proposed for the determination of peanut oil in mix- 

 tures are briefly reviewed. 



The method proposed by the author consists of treating the fatty acids ob- 

 tained from the oil in 200 cc. of ether with 50 cc. of a 30 per cent lead acetote 

 solution. The lead soaps of the liquid fatty acids dissolve in the ether, whili' 

 the insoluble soaps of the solid acids form an intermediate layer between the 

 aqueous solution and the ether. The clear ethereal solution is decanted through 

 a dry filter, the residue washed with ether, transferred to the filter, and again 

 washed. It is then transferred to a separatory funnel with 200 cc. of ether, the 

 fatty acids liberated with hydrochloric acid, the ethereal layer separated, 

 washed with water, the ether distilled, and the residue dried and finally tested 

 for arachidic acid by the usual tests. 



The determination of colza oil in mixtures with olive oil, R. Biazzo and 

 S. ViGDOKciK (Ann. Chim. Appl. [Rome], 6 (1916), No. 9-12, pp. 1S5-195).— 

 Earlier work on the subject is reviewed. 



The method proposed by the author depends on the concentration of erucic 

 acid, its conversion into behenic acid, and the identification of the latter. The 

 fatty acids from 20 cc. of the oil are dissolved In 180 cc. of anhydrous acetone, 

 the solution heated to boiling, and treated with 20 cc. normal potassium 

 hydroild. The precipitated acid potassium soaps are filtered off, washed with 

 acetone, dissolved in water, decomposed with hydrochloric acid, and the fatty 

 acids extracted by ether. The ethereal solution is shaken with lead acetate, 

 and the insoluble lead soaps treated for the determination of arachidic acid as 

 noted above. The soluble lead soaps are decomposed with hydrochloric acid, the 

 free acids separated, and then hydrogenated in the presence of palladium cata- 

 lyzer. The hydrogenated acids are fractionally crystallized and their melting 

 point determined. 



On the determination of theobromin and cafEein in cocoa and chocolate, 

 G. Savini (Ann. Chim. Appl. [Rome], 6 (1916), No. 9-12, pp. 247-250).— In the 

 procedure described 12 gm. of the pulverized sample is treated with 70 cc. of 

 petroleum ether in a 500-cc. flask and heated on the water bath for 10 minutes. 

 The liquid is then decanted and the op)eratlon repeated with two portions of the 

 solvent. 



The defatted material is transferred to a flask and boiled for about one hour 

 with 5 cc. of 10 per cent sulphuric acid and about 250 cc. of water. During the 

 heating the contents are occasionally shaken, and finally made up to volume 

 (300 cc.) at about 30° C. and filtered. Two hundred and fifty cc. of the filtrate 

 (corresponding to 10 gm. of the original substance) is evaporated In a porcelain 

 dish after the addition of magnesia to make the mixture alkaline and 10 gm. 

 of fine sand. When the mass attains a slrupy consistency and about 8 to 10 

 gm. of magnesia have been added It Is allowed to cool, pulverized In the mortar, 

 and extracted with chloroform to which 0.25 cc. of concentrated ammonium 

 hydroxid has been added. The extraction is repeated several timeii until about 

 500 cc. of chloroform has been used. The solvent Is then removed by distilla- 

 tion. The residue obtained is of sulticient purity to be weighed directly. The 



