RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY. 



The use of corrosive sublimate for the preservation of samples of milk 

 for analysis, P. Gr^lot {Jour. Pharni. et Chim., 6. ser., 25 (1907), No. 9, pp. 

 Ji2S-.'i.iS) . — Of the various antiseptics tested for the preservation of milk sam- 

 ples, mercuric dilorid has given the best results in the author's experience. 

 The bichlorid is rciKlered more soluble by the addition of one-fourth of its 

 weiflht of ammoniuiii clilorid. A tablet suitable for preserving a 2.")0 cc. sami)le 

 of milk would contain 0.0.5 gm. of mercuric chlorid and 0.012.5 of ammonium 

 chlorid. and would lower the freezing point ().00<J° C. The use of such tablets 

 would avoid, according to the author, the many inconveniences of i)otassium 

 bichromate. 



The determination of fat in cream, M. S^iegfeld {Molk. Ztg., 21 {1901), No. 

 13. pp. 'i.il, 332). — The Adams method and the Gerber acid method were com- 

 pared. In the acid method the cream was weighed but not diluted with water. 

 The averages of duplicate determinations by both methods agreed closely. 



Determination of fat in condensed milk, S. Hals and O. B. Klykken 

 {Zixchr. Littcrsiich. Nahr. u. Geuussmtl., 13 {1907), No. 6, pp. 338-3/(5).— 

 Comparative determinations were made by the methods of Gottlieb, Adams, Ger- 

 ber, and Schmid. The highest I'esults were obtained by the Gerber method. In 

 general, the results by the Gottlieb, Adams, and (ierher methods were unaffected 

 hy the addition of sugar. This was not true, however, of the Gerber metliod 

 when the fat content of the milk was very low. 



The refraction of fats and fatty acids, R. K. Dons {Ztschr. Untersuch. 

 Nil In: II. (lciiii>!siittl., 13 {1907), No. .7, pp. 257-261). — The difference between the 

 index of refraction of butter fat and those of the insoluble fatty acids at a tem- 

 Iierature of 40° C. is from 11.2 to 11.5. In the case of cocoanut oil the differ- 

 ence is 1G.9, which is sufRciently great to permit of the detection by this means 

 of the adulteration of butter with cocoanut oil. 



The refractometric examination of milk and creani and its applicability 

 in food control, E. Baieb and P. Neumann {Ztsclir. VnicrsHch. Nahr. ii. 

 (IciiiimhiII.. 13 {1907), No. 7, pp. 369-38.'i, figs. -)).— The milk is treated with 

 acetic acid and alkaline-copper-carbonate solution and centrifuged. Determina- 

 tion is made of the index of refraction of the ether solution of the fat. A 

 talile is given which shows the percentages of fat corresponding to the different 

 degrees of refraction. Cream is diluted with 9 parts of skim milk of which the 

 fat content has been previously determined. Comparative determinations by 

 this method and the Adams and Gottlieb m(>thods are reported. The variations 

 were not mark(>d. 



Estimation of lactose and butter fat in milk chocolate, W. L. Dubois 

 {■Join: Anici: Chnn. Sue. 29 {1907), No. J/, pp. 556-561). — The author's results 

 were sunnnarized as follows : 



" In order to prove a milk chocolate true to name it is necessary to establish 

 the presence of desiccated milk. This may be done by estimation of lactose and 

 butter fat. 



1019 



