RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECHNY. 



Micro-chemistry, F. Emich {Bcr. Deut. Chem. Gesell., 43 (If) 10), No. 1, pp. 

 10-13). — A descriiition of general and special micro-chemistry, with particular 

 reference to the work of II. Behrens. 



Refractometry and its practical application, D. Sidersky (La Refrnctome- 

 irie et scs Applications PnUiqucis. I'aris, 0)09, pp. 112, figs. 39). — This vol- 

 ume contains a short description of the more important refractometers and the 

 principles upon which they are constructed. The practical application of 

 refractometers is also considered, and tables therefor are appended. 



Studies with the compensation polariscope, J. KoVxVR {Ostcrr. Ungar. 

 Ztschr. Zuckerindus. u. Landw., 37 (1908). pp. 618-633, 7'7'7-7'9//; ahs. in Ztschr. 

 Vntcrsuch. Xahr. u. Genussmtl.. 19 {1910), No. 2, p. 108).— In order to examine 

 substances other than sugars with the compensation polariscope it is necessary 

 to observe the following precautions: The apparatus, when employed with the 

 petroleum light and corlorless solutions, will yield results equivalent to those 

 obtained with the sodium light, if the light from the petroleum lamp is allowed 

 to pass through a strata of potassium bichromate solution which has a thick- 

 ness of either 15 mm. and a concentration of 1 : 100, or a thickness of 100 mm. 

 and a concentration of 0.33 : 100. If these conditions are not adhered to there 

 may be an error of as much as from 4 to 5 per cent. Colored solutions yield 

 results with the compensation apparatus only when the filtered light gives 

 orange-yellow colored fields. 



Characteristics of the fat of different animals, M. Raffo and G. Foresti 

 (Gaz. Chim. Ital., 39 (1909), II, No. 5, pp. UHi-i9, fig. 1; abs. in Analyst, 35 

 (1910), No. 407, pp. 68, 69).— The results of analyses of ox, calf, sheep, ass, and 

 horse fat are reported. The determinations made are the saponification number, 

 iodin number, Reichert-Meissl number, Hehner number, melting point, and vis- 

 cosity value. 



A peculiar precipitation of glycogen, E. Pfluger (Arch. Physiol. [Pfliiger], 

 121 (1908), pp. 641-643; abs. in Ztschr. Untersuch. Nahr. u. Genussmtl., 19 

 (1910), No. 2, pp. 101, i02).— Adding 2 volumes of alcohol to 1 volume of gly- 

 cogen solution yields a milky solution which allows filtration only after the pre- 

 cipitate has settled and the solution has become clear. If the filtration is 

 attempted previous to this very fine particles of the precipitate go through the 

 filter paper. The precipitate, which is a transparent varnlsh-like body, collects 

 on the bottom and sides of the vessel. The author shows that this phenomenon 

 is not due to the docomiiosition of the glycogen. 



Contributions to our knowledge of plant phosphatids, E. Winterstein and 

 L. Stegmann (Ztschr. Physiol. Chem., 58 (1909), No. 6, pp. 500-505; abs. in 

 ZentU. Gesam. Physiol, u. Path. Stoffwcchsels, n. ser., // (1909), No. 23, p. 

 891).— A carbohydrate phosphatid was isolated from the seeds of Lupinus albus, 

 which, on analysis, yielded 3.G jwr cent of phosphorus, 0.95 per cent of nitrogen, 

 and 1().3 per cent of carbohydrates. 



47147°— No. 1—10 2 "^ 



