AGRICULTUEAL, CHEMISTEY AGROTECHNY. 507 



dilute hydrocbloric acid of different concentrations and certain immiscible 

 solvents were determined. The data [obtained] indicate a method that gives 

 good results in practice and is of quite general applicability. Some figures have 

 also been obtained for other similar colors that will show where separations 

 can be made and can also be applied for qualitative differentiations." 



Determination of fat in feeding stuffs with trichlorethylen, R. Neumann 

 (Chcm. Ztff. 35 (1911), No. 112, pp. 1025, 1026).— The fat in rice-feed meal, 

 linseed-cake meal, linseed meal, linseed cake, palm-cake meal, cotton-seed meal, 

 ground barley, coconut cake, sunflower cake, peanut cake, brewers' grains, dis- 

 tillery slops, corn-germ-oil cake, soy-bean meal, and brewers' grain molasses 

 (freed from sugar) was determined with ether and trichlorethylene for the pur- 

 pose of determining the value of trichlorethylene as a solvent. The results 

 obtained compared very well with one another. 



In regard to Cornalba's rules as to the constancy of the soluble milk 

 constituents, H. Hoft {Milclno. ZentbL, 7 (1911), No. 8, pp. 361-SG3) .—TYie 

 results of examining the milk from 6 cows over a long period of time are here 

 given, and show that the constants for total soluble solid content of the serum 

 (6 per cent) as set down by Cornalba are apparently correct (see E. S. R., 

 26, p. 314). 



In regard to the significance and the practical value of the methods most 

 generally used for examining milk, H. Lenzen (Berlin. Tierarztl. Wchnschr., 

 27 {1911), No. 40, p. 7ff2). — In this article the significance and practicability 

 of the catalase, reductase, diastase, peroxidase, leucocyte (TrommsdorfE), and 

 hemolytic (Sassenhagen) tests are considered. 



In regard to determining the dirt content of milk, K. Sergee (Pharni. 

 Zentralhalle, 52 (1911), No. 17, pp. U9-455; aU. in Chem. Ztg., 85 (1911), No. 

 75, Repot., p. 309). — Fendler and Kuhn's method gave the best results. Ac- 

 cording to the author, milk that contains more than 10 mg. of dirt per liter 

 and has a superficial appearance of a dirty milk should be condemned. 



Determination of catalase in milk, O. Jaggi and J. Thomann (Bchweiz. 

 ^Vclmschr. Chem. u. Pharm., 1,9 (1911), Nos. 10, pp. 129-137; 11, pp. 11(5-150; 

 abs. in Chem. Ztg., 35 (1911), No. 61, Repert., p. 2.57).— The catalytic activity 

 of milk stands in close relation to the leucocyte content. With an increase in 

 leucocytes there is a corresponding increase in catalase. No relation seems to 

 exist between the fat and dry substance of milk and catalase. For determining 

 catalase the Gerber-Lobeck apparatus (E. S. R., 24, p. 213) was found to give 

 the best results. 



In regard to reduction ferments. — II, Reduction of nitrates by the per- 

 hydridase-aldehyde-water system, A. Bach (Biochem. Ztschr., 83 (1911), 

 No. Jf, pp. 282-290; abs. in Chem. Ztg., 35 (1911), No. 106, Repert., p. U5).— 

 Fresh cow's milk was found to accelerate the reduction of nitrates by aldehyde 

 in such a manner that nitrite formation is noted after from 1 to 2 minutes. 

 Boiled milk having aldehydes and fresh milk present, but no nitrates, does not 

 show any nitrite production. The rapidity of the reduction process and the 

 amount of reduction increases with the aldehyde concentration. The same holds 

 good for the nitrate concentration. Besides the reduction of nitrates a destruc- 

 tion of the nitrite produced also takes place, and both processes seem to in- 

 crease with the temperature. The optimum temperature lies between 60 and 

 70° O. Acetaldehyde acts better than foi-maldehyde. 



A reaction for differentiating woman's and cow's milk, G. Tugendreich 



(Berlin. Klin. Wchnschr., ^8 (1911), No. 5, p. 22^; abs. in Chem. Ztg., 35 (1911). 



No. Ifl, Repert., p. 166). — To 3 cc. of the milk in question an equivalent amount 



of 1 to 2 per cent silver nitrate solution is added, then shaken and brought to 



35693°— No. 6—12 2 



