AGRICULTURAL CHEMISTRY — AGROTECHNY. 507 



develop in milk in which the Danish streptococcus will not grow or die) ; (4) a 

 Russian lactic acid streptococcus which yields a thick, ropy coagulum and will 

 grow in milk of not especially good quality (the chief microscopical difference 

 between this organism and the Danish strain is the fact that the former has a 

 characteristic size and appears in elongated pairs) ; and (5) the Bacillus 6m?- 

 (jaricus (Metchnikoflf) which is characterized by developing under abnormal 

 conditions and will grow in milk of poor quality. An addition of a large 

 amount of bicarbonate of sodium will not hinder the development of this or- 

 ganism, and it forms a tenacious coagulum. 



If the milk under examination is of very good quality it will, after coagula- 

 tion, show the following microscopic picture : Numerous Danish streptococci 

 appearing as elongated diplococci and many small lactic acid bacteria (Giiuther 

 and Jaroslaw diplococci), a few Russian streptococci, and a few B. bulgaricus. 



Milk of medium quality requires about two hours longer for coagulation than 

 milk of good quality, and in curdled milk the Danish streptococci are prac- 

 tically absent and are displaced by many small cocci, the Russian streptococcus, 

 and the B. bulgaricus. In the poor milk the small lactic acid bacteria die, the 

 Russian streptococci develop slowly and die, and only the B. bulgaricus survives. 



A fresh milk or a milk which has been cooled down to and stored between 6 

 to 8° C. after drawing are the only ones which will yield satisfactory results 

 with the test. 



The value of this method for controlling the milk supply, especially milk 

 which is designed for infant feeding and for butter making is pointed out. 



A simple microscopical method for judging the micro-organism content 

 of milk, A. RosAM { Milch w. ZetitbL. 42 (1913), No. 11, pp. 333, 53//).— The 

 method consists of spreading a platinum loopful (of a definite size and weight) 

 of milk (previou.sly heated with an equal volume of methylene blue and a little 

 pyridin in a metal spoon) on a microscopic slide, covering it with a cover glass, 

 and counting the number of bacteria per microscopic field. The number of 

 bacteria are calculated from this finding by means of a formula which is stated. 

 The method is a rapid one. 



About the detection of boiled and raw milk, A. BalAzs (Abs. in Ghent. Ztg., 

 37 (1913), No. 54, p. 55^).— The test is as follows: 



To 5 cc. of milk add 2 cc. of a copper sulphate solution which contains 69.2G 

 gm. of copper sulphate per liter, shake, and filter ; then to 5 drops of the clear 

 and transparent filtrate add Adamkiewicz's reagent (1 part sulphuric acid 

 and 2 parts of glacial acetic acid). Warm carefully without boiling, shake, and 

 allow to stand for a while. The serum of boiled milk remains colorless, while 

 raw milk shows a violet red color. Its greatest intensity occurs within 10 to 15 

 minutes. 



Preliminary report in regard to Romer's work on Schardinger's reaction 

 of cow's milk, W. Rullmann (Biochem. Ztschr., 48 (1913), No. 1-2, pp. 155, 

 156). — ^A discussion in regard to Romer's work (E. S. R., 27, p. 810) on the 

 occurrence of Schardinger's reaction in the initial milk of cows. See also a 

 l>revious note (E. S. R., 27, p. 13). 



Alteration of milk preserved with potassium bichromate, G. Hinard (Ann. 

 Falsif., 6 (1913), No. 54, pp. 233-231) .—The changes produced in a milk con- 

 taining 0.098 per cent of potassium bichromate were studied. 



In the total solids a loss of 1 gm. per 100 cc. of milk was noted in six months. 

 The figures for fat or ether extract were very discordant owing to the difficulty 

 of obtaining a homogenous sample of milk. The loss in fat-free dry substance 

 was similar to that of the total solids. The lactose figures for the first two 

 months were very variable and in some cases became higher than at the 

 outset, but after a lapse of six months the losses were very rapid and amounted 



