AGEICULTUEAL CHEMISTEY AGROTECHNY. 13 



fat-free dry substance, polarization, sediment, acidity, freezing point, chlorin, 

 chlorid of calcium serum refraction, and nitrates) for determining tlie quality 

 of milk. 



The difiEerentiation of animal from plant fats, with special reference to 

 Welman's reaction and the utility of Welman's reagent for differentiating 

 butter and margarin, Bieemann {Ztschr. Veterindrk., 26 (1914), No. 4, pp. 

 168-170). — Welman's test is not deemed satisfactory for distinguishing animal 

 from plant fats. It can, however, be used for detecting margarin in butter. 

 The method is much easier to conduct than the furfural or Reichert-Meissl tests. 



Estimation of saccharose in frozen and thawed beets, E. Satllakd {Compt. 

 Rend. Acad. Set. [Paris], 160 {1915), No. 12, pp. 361-363; Jour. Agr. Prat, n. 

 ser., 28 (1915), No. 38, pp. 266-268). — ^Beets which were frozen were found to 

 contain one or more substances which could be hydrolyzed with hydrochloric 

 acid at 69° C, but not with invertase at 50 to 55°. 



The comparative study of different methods of inversion (Clerget, Herz- 

 feld, modified Herzfeld, Andrlik, Pellet, Saillard, and Ogilvie), M. A. Gillet 

 (Bui. Assoc. Chim. Sucr. et Distill., 31 (1914), No. 12, pp. 992-1004) .—It was 

 found that direct alkaline polarization by the Clerget and Herzfeld methods and 

 acid inversion polarization do not give accurate results. This is due to the inter- 

 ference of optically active substances which in all probability are amino acids. 

 Acid direct polarization employing hydrochloric acid and urea will give accu- 

 rate results with beet molasses, but the method is not deemed practical because 

 it necessitates rapid working in order to prevent inversion of sucrose by the 

 acid. Sulphurous acid, when employed according to the method suggested by 

 Pellet and Ogilvie in 1912, will give identical results and with less trouble. 

 The neutral double polarization proposed by Saillard is satisfactory but is difficult 

 to conduct, and can not, therefore, be used in routine factory work. The in- 

 vertase method of Ogilvie gives results which agree closely with those yielded 

 with the Pellet and Andrlik modifications. The most accurate and practical 

 method is deemed the Pellet procedure, which uses sulphurous acid in excess 

 in making the direct polarization. 



Reduction of copper oxid in alcohol vapor in reducing sugar deteiinina- 

 tions and copper analysis, A. Weddebbuen (Jour. Indus, and Engin. Chem., 7 

 (1915), No. 7, pp. 610, 611). — The precipitate of suboxid of copper is collected 

 in an alundum filtering crucible, using Spencer's filtering funnel with suction 

 and washing with hot water and alcohol. The crucible is then heated to redness 

 to burn off organic matter, cooled until the redness just begins to disappear, 

 and immersed in an atmosphere of alcohol vapor. The reduction to metallic 

 copper is said to be almost instantaneous and complete, and the results obtained 

 are identical with those by reduction in hydrogen, closely approximating the 

 electrolytic method. 



Ether-soluble matter in the nitrogen-free extract of feedstuffs, J. B. 

 Rather (Jour. Indus, and Engin. Chem., 7 (1915), No. 7, pp. 613-615). — 

 Previously noted from another source (E. S. R., 32, p. 709). 



The determination of lint in cotton-seed meal, R. N. Beackett (Jour. Indus, 

 and Engin. Chem., 7 (1915), No. 7, pp. 611, 612). — The determination of lint 

 in cotton-seed meal has been found impracticable by the methods heretofore 

 proposed. What appeared to be a better procedure consists in dissolving the 

 lint in zinc chlorid solution. 



METEOROLOGY. 



Text-book of meteorology, J. von Hann and R. StJBiNG (Lehrhuch der 

 Meteorologie. Leipsic: C. H. Tauchnitz, 1915, 3. rev. ed., pp. XIV +847, pis. 28, 

 figs. 108).— In this edition the plan followed in one of the earlier editions of 



