414 EXPERIMENT STATION EECOED. 



in vanilla extracts has been discussed from the point of view of the distribution 

 ratio. The methods now in use for salicylic acid, benzoic acid, and j3-naphthol 

 have been studied and found satisfactory from this point of view. A method 

 has been suggested for the analysis of saccharin by extracting with amyl 

 acetate and a modification of the present method with sulphuric ether proposed 

 which gives definite I'esults. It has been shown in the analysis of caffein (in 

 the particular case referred to) that the amount of chloroform used for the 

 extraction was excessive. The fact has been emphasized that a larger number 

 of extractions, using a smaller volume of solvent for each washing, is better 

 than a fewer number of extractions using a larger amount. A much more 

 extended study of the methods of extraction is being carried on in this labora- 

 tory at the present time." 



A reaction of succinic and malic acids, W. CE. de Ck)NiNCK (Bui. Soc. Chim. 

 France, 4- set:, 15 (1914), No. 2, pp. 93, 94; «&«. in Jour. Chem. Soc. [London'\, 

 106 (1914), No. 617, II, p. 224).— When a concentrated aqueous solution of 

 succinic acid is added to a suspension of several grams of calcium salicylate 

 in a little cold water and the mixture gently warmed, a pale pink coloration is 

 quiclily obtained which persists for several days even when the mixture is 

 exposed to direct sunlight. Under similar circumstances malic acid develops 

 a delicate pink coloration which gradually disappears when the mixture is 

 gently boiled. It is comi^letely removed after several hours and the liquid 

 then becomes yellowish brown in color. 



Methods for the detection and investigation of tr3rptoproteases, F. M. Mae- 

 EAS (CentU. Bakt. [etc.^, 1. AM., Orig., 14 {1914), No. 5-6, pp. 505-515).— The 

 methods studied were the fibrin method, Mett's method, Fermi's gelatin plate 

 method, the serum plate method according to Jochmann and Miiller, the Gross 

 and Fuld casein method, and the biuret, tryptophan, and tyrosin reactions. 

 Fermi's method gave more satisfactory results than those of either Jochmann 

 and Miiller or Gross and Fuld. 



The distillation of volatile fatty acids and the value of the Reichert- 

 Meissl number, J. Prescher (Ghem. Ztg., 38 {1914), Nos. 112-113, pp. 1081- 

 1083; 114-115, pp. 1091-1093).— A digest of the literature. 



Catalase and reductase determination in cow's milk in practice and the 

 relation between catalase and reductase on the one hand and the specific 

 gravity, fat, and acidity on the other, A. Stetteb {Milchw. ZenthL. 43 {1914), 

 No. 14, pp. 369-381, figs. 2). — The morning and evening milk from two dairies 

 was examined fairly regularly during the year 1913 for specific gravity, fat con- 

 tent, reductase, and acidity. The cows were fed chiefly hay and various concen- 

 trates, with beet tops and leaves during the fall months. 



No relation was found to exist between the catalase and reductase figures and 

 the specific gravity or fat content of milk. On the other hand, a high acidity 

 degree almost always pointed to a high reductase content. No correlation was 

 found between acidity and the catalase figures, as milk with a high acid value 

 often showed a normal catalase figure. It often occurred that the catalase and 

 reductase figures of the morning and evening milks were alike but, generally 

 speaking, the figures for each were highest in the evening milk. The catalase 

 figure varied considerably from day to day and the reductase test also showed 

 veiy marked variations. In most instances a milk which decolorized (reductase 

 test) in one-quarter hour also had a high acid value. Although a high catalase 

 and reductase figure lead to a suspicion of pathological milk, still one must be 

 cautious when pronouncing a condition pathological on the basis of these tests. 



Description of the cryoscope, and several freezing-point determinations 

 of a single sample of fresh milk with varying degrees of supercooling, ]\I. C. 

 Dekhuizen {Chem. Weekbl., 11 {1914), No. 4, pp. 126-131, fig. 1; abs. in Jour. 



