514 EXFEKIMHNT STATION KKCOKD. 



solution of the casein particles. After all is dissolved, wasli off the stopper 

 with neutral distilled water and titrate directly with tenth-normal sulphuric 

 acid solution. A blank test should be run in each instance, as in the experience 

 of tlie author a blank of 0.2 to 0.3 cc. was invariably obtained. The difference 

 between tlie cori-ected acid reading and the 10 cc. of alkali gives directly the 

 percentage of casein in the milk. 



A rapid method for the estimation of fat in homogenized milk, Hoyberg 

 (ZtHchr. Flcisch u. Milch hy(/.^ 19 {1909), No. 10, pp. 352-3.55 ) .—The fat content 

 of homogenized milk can not be determined accurately by the usual Gerber 

 method. Good results can be obtained by heating the milk in a water bath 

 at 60 to 65° C. for 5 minutes before applying the test. The author recom- 

 mends the direct addition of the warm milk to the sulphuric acid and the 

 amy! alcohol, and to avoid pouring the former on the sides of the butyrometer. 



Comparative investigations on the newer methods for the detection of 

 the addition of water to milk, Coknalba (A&.s. in Chem. Ztg., 33 (1909), 2Vo. 

 69 p. 628). — The refractometric. densimetric, and cryoscopic methods are dis- 

 cussed. With the refractometric method accurate results are obtained for 

 casein and fat only when these are present in large amounts. The density 

 determination of the serum will furnish accurate results for dilutions of the 

 milk down to 10 per cent. The freezing point method did not give good results. 



Detection and determination of formaldehyde in milk, L. Grunhut 

 (Ztschr. Anahjt. Chem., J,S (1909), No. 7-.S, pp. .W2-.506).—K compilation of 

 methods. 



Observations with the Schardinger reaction of milk, K. Schern (Biochem. 

 Ztschr.. IS (1909), No. 3-5, pp. 261-2SJi). — It is shown that milk from cow's in 

 the first stages of lactation did not always give the Schardinger reaction when 

 treated at Brand's temperature, 65 to 70° C. 



With cows which had been recently suckled no reaction was apparent, while 

 those where the calves had died reacted readily. A cow in the early stages of 

 lactation with one quarter inflamed gave a milk from that quarter which de- 

 colorized. Another cow, with no inflamed quarter but whose calf died, gave 

 milk at first which was decolorized in the bottom of the test tube while the 

 upper layers remained blue, but the milk obtained on the next day was decol- 

 orized completely. The author concludes from this that the feeding of the 

 offspring has some influence on the reaction. Experiments made with cows 

 in late periods of lactation showed that in almost every instance the reaction 

 was present. An attempt to determine whether the reaction could be employed 

 to detect pathogenic milks was imsuccessful. 



The coloration was found to set in better at 45° with milks from the first 

 stages of lactation, while the optimum for milks from late periods of lactation 

 was 65 to 70°. With the milks from late periods of lactation the bodies which 

 brought about the Schardinger reaction were i)resent in a preformed state, but 

 with those from the early stages they were mostly not present at all. 



The enzyms of milk, F. Bordas and F. Touplain (Compt. Bend. Acad. 8ci. 

 [Paris], 1J,8 (1909), No. 16. pp. 10.57-1059; ahs. m Chem. Zenthl., 1909, I, No. 

 26, pp. 2005, 2006). — The relation of the decomposition of hydrogen peroxid and 

 the color reaction to the presence of peroxydases and catalases was not estab- 

 lished. 



When samples of milk which had been heated to 80, 100, and 120° C, re- 

 spectively, and did not give the Storch reaction, were centrifuged 3 layers were 

 obtained, the upper being cream; the middle, fluid; and the lowest, sediment. 

 The cream layer and the sediment then gave the reaction, while the fluid did 

 not. Raw milk filtered through a bisque filter did not give the reaction, and 



