AGRICULtURAL CHEMISTRY — AGROTECHNY. 413 



The best results were obtained wbeu the dry solid subucetate of lead, i)rei)ared 

 according to Horne, was employed. 



The unification of tables for comparing' the specific gravity with the 

 sugar content, E. Saillakd (Zt.schr. Ver. Dcut. Ziickcriudu.s., 1909, \o. C'/G, 11, 

 pp. 1000-1001). — A disciissrou in reference to the temperature for taking the 

 specific gravity and the temjierature at which the glassware required is stand- 

 ardized. 



Befractometry of molasses, Saillard (Circ. HeM. Syndicat Fair. Sucre 

 France, 1909, A'o. 10G5 ; abs. in Chem. Ztg., 3S (1909), No. 118, Repert., p. 507).— 

 In a comparison of the refractometric and usual drying methods for dry sub- 

 stance in molasses the difference was less than 0.24 per cent in 60 per cent of 

 the cases and greater in 40 per cent. In only a few instances was the difference 

 more than O.S ])er cent. 



Coppered vegetables and determining copper therein, G. Stein (Ztschr. 

 Unfersueh. Xahr. u. GenuHKintL, 18 {1909). Xo. 9, pp. 5S8-.5.50). — This is a gen- 

 eral discussion of the subject and of an effort to ascertain the most accurate 

 method to determine the copper in canned peas, beans, and the accompanying 

 liquor. The methods discussed are Brebeck's, von Graff's modification of Bre- 

 beck's method, and the electrolytic method. A descrijjtion of a new method for 

 which is claimed the simplicity of the von Graft" method and the accuracy of the 

 electrolytic method is given. 



Contributions to the examination of cocoa and its preparations, A. Proch- 

 Now (Bfitruf/c zur UntvrsuchiuKj tics Kdl-uos und ftcintr I'riipnntlc. Disfi. Tech. 

 Hoehschulc Braunschueig, 1909, pp. 70). — This investigation dealt chiefly with 

 determining the xanthin bases, the fat content, the purity of the fat, and the 

 presence of cocoa shells (a) by determining the iodin number, (b) by determin- 

 ing the crude fiber, (c) estimating the pentosans and methylpentosans. 



The author concludes from his work that the Katz-Beckurts-Fromme method 

 for determining the theobromiu is the best. For fat, Soxhlet's method is to be 

 retained. The range of fat for cocoa (now 40 to 54 per cent) is recommended 

 to be raised to from 50 to 50 per cent. The purity of the fat should be de- 

 termined by the usual methods. No new method for testing for animal fats 

 was discovered. To detect gross adulteration the Filsinger-Drawe method and 

 the pentosan determination according to Tollens-Krober are recommended. 



Chemical composition of tea leaves during various stages of growth, S. 

 Sawamura (BuL Imp. Cent. Agr. Expt. Sta. Japan, 1 (1907), No. 2, pp. lJt5-H7 ; 

 abs. in Chem. Zentbl., 1908, I, No. 9, pp. 668, 867; Ztschr. Untersuch. Nahr. u. 

 Genussintl., 18 (1909), No. 10, p. 619). — As the growth progresses the water, 

 total nitrogen, and thein content diminishes while the ether extract, crude 

 fiber, and tainiin become greater. 



The surface tension and viscosity determined in milk by Traubes stalag- 

 mometers, R. Burri and T. Nussbaumer (Biochem. Ztschr., 22 (1909), No. 1-2, 

 pp. 90-102). — The authors sought to determine the changes which occur in the 

 viscosity and surface tension of milks kept at a constant temperature of 20° C. 

 and further the influence of cooling on the viscosity and surface tension. 



It is shown that during the first 12 hours there is a decrease in the surface 

 tension but a slight increase in the viscosity. Cooling does not, however, act in 

 the same manner. In a milk where the temperature did not go lower than 20° 

 the surface tension fell only slightly, but cooling to 10° produced a marked de- 

 pression. The surface tension of the milk reaches the minimum depression 

 limit which could be established upon cooling the milk to 0° or freezing it. 

 The viscosity test showed no such great variation on cooling. Heating a milk, 

 which had been cooled, back to body temperature (37°) did not restore the 

 surface tension of the original milk. 



