1917] AGRICULTUEAL CHEMISTRY AGROTECHNY. 113 



of acetylmethyl-carbinol and that this substance is a normal constituent of the 

 vinegar. 



The experimental procedures used in the investigation are described in detail. 



The analysis of Peruvian bark. J. W. Commelin {Meded. Kina Proefstat. 

 [Dutch East Indies], No. 1 (1912), pp. 38). — This paiuplilet describes and dis- 

 cusses in detail procedures for the determination of moisture, total alkaloids, 

 quinin, and cinchonidin. Simplicity of methods was the aim, since they were 

 to be used in cultural experiments. Formulas for calculating the quantity of 

 total alkaloids and cinchonidin are included, together with correction tables for 

 polarimetric I'eadiugs, etc. 



The determination of the various forms of nitrogen in forage plants, 

 N. Passekini (Ann. Chim. Appl. [Rome], 6 (1916), No. 5-8, pp. 162-164) .—The 

 author describes a procedure by which the forms of nitrogen in the hydrolyzed 

 sample^re determined as uuclein nitrogen, amino acid nitrogen, ammonia nitro- 

 gen, and preformed amid nitrogen. The procedure consists essentially of 

 determining the pure protein according to the procedure of Kellner in a 1 gm. 

 sample. In another 5 gm. hydrolyzed sample, after treating according to Kell- 

 ner's method, the copper is removed with hydrogen sulphid and the ammonia 

 determined in an aliquot of the filtrate. The nonhydrolyzable nitrogen, con- 

 sidered to be nuclein, is then determined in the residue. The amino acid 

 nitrogen is determined by subtracting the sum of the ammonia and nonhydro- 

 lyzable nitrogen from the total protein nitrogen. 



A table showing the distribution of nitrogen in whole wheat, wheat bran, 

 wheat flour, maize, beans, and vetch is submitted. 



The estimation of hydrocyanic acid and the probable form in which it 

 occurs in Sorghum vulgare, J. J. Willaman (Jour. Biol. Chem., 29 (1917), No. 

 1, pp. 25-36). — The author, at the Minnesota Experiment Station, considers the 

 methods in general use for the determination of hydrocyanic acid in plant tis- 

 sues of questionable accuracy because of the difficulty of obtaining complete 

 hydrolysis of the glucosids by means of acids and because of the retention of 

 the cyanid from distillation by the tissues involved. 



Analytical data show that the hydrolysis of durrin, the glucosid in sorghum, is 

 best accomplished by autolysis, the reaction taking place rapidly at 45° C. " Re- 

 tention of hydrocyanic acid by the tissues during distillation can not be pre- 

 vented by the presence of tartaric acid, nor can it appreciably be lessened by 

 distilling under reduced pressure." Hydrocyanic acid occurs in 8. vulgare in 

 two forms, as a glucosid and as a nonglucosid, the nature of which is yet un- 

 known. The nonglucosidic form is considered to be probably responsible for 

 the poisoning of stock. This form can be distinguished from the glucosidic 

 by grinding the leaves in the presence of 5 per cent tartaric acid to prevent 

 any enzym action and then distilling. 



Relation of the fat in milk to the solids-not-fat, L. P. Brown and C. V. 

 Ekeoth (Jour. Indus, and Engin. Chem., 9 (1911), No. S, pp. 297-299, fig. 1).— 

 The authors have devised a zone chart from the figures for percentage fat and 

 percentage solids-not-fat of a large number of published analyses of milk. 

 The chart shows the approximate chemical composition of normal milk and i^ 

 intended as a guide in fixing legal standards and also in detecting adulteration. 



It is indicated that " a milk standard having regard only for the total solids 

 is illogical. Most of the legal milk standards in force in the several States of 

 the Union as well as that of the Federal Government are unbalanced and, there- 

 fore, incapable of enforcement." 



The detection of preservatives and coloring matter in milk, I. M. Kolt- 

 HOFF (Pharm. Weekbl., 53 (1916), No. 48, pp. 1609-1618) .—The author briefly 



