AGRICULTURAL CHEMISTRY AGROTECHNY. 413 



of the chemical methods for the precipitation of casein. Colostrum and blood- 

 serum proteins behave in the same manner as those of millc and whey. The 

 albumin and globulin of serum, milk, and colostrum, according to the authors, 

 are probably identical. 



In regard to the refractometry of calcium chlorid milk serum., G. Fendlee 

 {ZUchr. Untersuch. ^'ahr. u. Gemissmtl., 20 (.1910), No. 10, pp. 61,0, 67/1). —The 

 author points out that the literature in regard to Zeiss's immersion refractom- 

 eter does not draw attention to the fact that a correction must be applied to 

 the refractive indexes as read off with the instrument. He, therefore, corrects 

 some of his findings in the work with the calcium chlorid milk serum which has 

 already been reported (E. S. R., 24, p. 012). 



The value of the various chemical and physical methods for the detection 

 of adulteration in milk and butter, C. Granvigne and G. Cassez {Ann. Falslf., 

 4 (1011), No. 28, pp. 77-85). — This is a discussion and study in regard to the 

 value of different methods for detecting adulterations of milk, such as watering 

 and the removal of creana, and the determination of fat-free dry substance, 

 lactose, and the composition of butter. 



Tests and observations in regard to the separation of water from butter, 

 O. HoFFMEisTEE (Mollc. Ztg. [Hildesheim], 25 (1911), No. 16, pp. 211, 272).— 

 The author sought to determine the cause for the separation of water from 

 butter samples, but found no definite relationship existing between the separa- 

 tion of water and the consistency and water content of the butter. In attempt- 

 ing to determine the degree of water separation, he found that the amount of 

 water was different in the various areas of the same sample, and that the 

 samples of butter containing the highest amounts of water had the super- 

 ficial apea ranee of being the driest. 



In regard to the causes for the separation of water the author believes that 

 these may be looked for in the various methods utilized for the manufacture 

 of butter, and possibly in the variation in chemical composition and the 

 mechanical structure of the fat. The analytical results for moisture obtained 

 with Funke's apparatus and the Hesse-Rose-Gottlieb method showed that the 

 former gave the higher results. 



A new method for determining volatile fatty acids, E. Welde (Biochem. 

 Ztschr., 2S (1910), No. 5-6, pp. 50-'i-522; abs. in Zentbl. Biochem. u. Biopliys., 

 11 (1910), No. 1, p. 3).— The author modified the old method for volatile fatty 

 acids in so far that the acids are distilled off in a vacuum with steam. 



The use of glycerin in saponifying fats in the titer test, R. H. Keeb (Jour. 

 Indus, and Engin. Cliem., 3 (1911), No. 2, pp. II4, 115). — The method, which 

 is a rapid one, is as follows : 



" Fifty cc. of high-grade chemically pure glycerin (97 per cent glycerin) and 

 20 cc. concentrated caustic potash solution (100 gm. KOH dissolved in 100 cc. 

 distilled water) are placed in a liter flask and warmed gently on an asbestos 

 board over a low flame. When hot, 50 gm. of the molten fat are poured in and 

 the flask rotated gently. Saponification begins at once and is soon complete, 

 although there is usually some foaming before the mixture becomes clear. 

 Complete saponification is shown by the mixture becoming perfectly clear 

 and homogeneous. When saponification is complete the flame is removed and 

 500 cc. of hot water added, cautiously at first, to avoid excessive foaming. 

 The flame is then replaced and sufficient dilute (1:3) sulphuric acid added to 

 decompose the soap. A few minutes' boiling gives a clear layer of fatty acids. 

 The acids are then washed and dried in the usual way. The process is quite 

 rapid, clear acids being obtained in 20 to 25 minutes. The results show perfect 

 agreement with standard methods." 



