AGRICULTTJEAL CHEMISTRY — AGROTECHNY. 505 



start of the process of concentration. When the concentration reaches the 

 necessary degree for the production of sweetened condensed milk, the electrical 

 conductivity decreases rapidly for each increase in concentration of the milk. 

 . . . From theoretical considerations supported by experimental work in the 

 laboratory, there is every reason to think that the measurement of electrical 

 resistance or conductivity should furnish an accurate method of following the 

 progress of concentration in the manufacture of sweetened condensed milk." 



Dry milk with, particular reference to determining the fat content, Utz 

 (MilcJm. Zenthl., 43 (1914), No. 5, pp. 113-120).— The determination of water, 

 ash, nitrogen, and lactose in dry Inilk is comparatively simple but certain diffi- 

 culties are experienced when fat is to be estimated by the usual methods. A 

 modification of the Boudzynski-Ratzlaff method and the Polenske method (E. 

 S. R., 25, p. 12), is recommended for determining the fat in this kind of mate- 

 rial. Gerber's method did not yield satisfactory results. 



The acidity degrees ( Soxhlet-Henkel ) were determined in 26 samples of pow- 

 der made from whole milk, cream, partly skimmed milk, and skim milk. The 

 method employed is as follows : About 80 cc. of a neutral alcohol-ether mixture 

 is poured over 10 gm. of the air-dry milk powder, shaken at intervals, and after 

 24 hours the mixture is made up to a volume of 100 cc. The number of cubic 

 centimeters of decinormal alkali required to neutralize 50 cc. of the solution is 

 calculated in the same manner as employed for fats and oils. 



Some data are being collected regarding the acidity of dry milk stored over a 

 long period of time. 



A critical study of Cesaro's method for the detection of coconut fat in 

 butter, L. Stceclin (Ann. Falsif., 7 {1914), No. 67, pp. 223-231).— It is stated 

 that the Cesaro method'' can be employed for detecting coconut fat in butter. 

 If the fat added is solid as little as 10 per cent can be detected, but when added 

 in a liquid state only 25 per cent can be noted. Additions of less than 10 per 

 cent can not be noted with certainty. 



Rapid analysis of butter: Estimation of nonfats, E. Isnard (Ann. Falsif., 

 7 {1914), No. 69, pp. 369-371). — For the purpose of determining especially the 

 nonfatty materials in butter, from 2 to 3 gm. of butter is weighed into a porce- 

 lain dish, and 10 cc. of water is incorporated on the water bath. The emulsion 

 is then brought into a separatory funnel and cooled to 35° C. Ten cc. of water 

 and from 20 to 30 cc. of ether are then used to remove the fatty materials ad- 

 hering to the sides of the dish, the washings are transferred to the funnel, and 

 the mixture is shaken cautiously. After 15 minutes standing the aqueous layer 

 with the supernatant casein is drawn off, two portions of 10 cc. each of water 

 are added, and the process of shaking with water and drawing ofE is repeated 

 twice. The ether layer is then transferred to a dish, the ether is dispelled by a 

 current of air, and the residue dried at 100° O. In the aqueous portion the 

 casein is determined by collecting it on a filter. The total solids contained in 

 the filtrate represents casein, albumin, and salts. The latter can be determined 

 by incinerating the residue. 



Extraction of neutral fats from ripe sheep's milk cheese for the purpose of 

 determining the chemical and physical constants of the same, F. Barany 

 (Ztschr. Untersuch. Nahr. u. Genussmtl., 28 (1914), No. 1, p. 33; ads. in Ztschr. 

 AngeiD. Chem., 27 (1914), No. 72-73, Referatenteil, p. 533).— For this purpose 

 80 gm. of cheese is rubbed up with 15 cc. of water to a paste and brought up to 

 a bulk of 250 cc. by the addition of water. The mixture is neutralized toward 

 phenolphthalein, with potassium hydroxid solution made up to a bulk of 300 cc, 

 shaken vigorously with 300 cc. of petroleum ether, 300 cc. of 95 per cent alcohol 



"Acad. Roy. Belg., Bui. CI. Sci., 1907, No. 12, p. 1004. 

 7700°— No. 6—15 2 



