DAIRY FARMING DAIRYING. 259 



with the danger is to educate the people to use only milk which they 

 have themselves ])asteuii/ed or sterilized. 



In conclusion, he states Dr. Law's views in regard to the dangers 

 from consuming the meat and milk of tuberculous animals, which he 

 criticises. 



The present status of bacteriological investigation in dairying, 

 H; WeigmaNN {Milch Ztcf., 25 {1896), ¥os. 10, pp. 147-150; 11, pp. 163- 

 166). — This is a lecture delivered before the German Dairy Union. The 

 progress in dairy bacteriology during the past 5 years is reviewed in a 

 general way. The origin of the bacteria in milk, sources of contamina- 

 tion, relation of food and of cleanliness in the stable to contamination, 

 milk and butter ^'faults," the use of pure cultures for ripening cream, 

 sterilizing and pasteurizing milk, and the ripening of cheese are treated 

 at greater or less length. 



After summing up the work on the ripening of cream and the employ- 

 ment of pure cultures of different kinds, the author says: "It will be 

 seen that the effort is to produce artificially, not only pure butter of 

 good keeping quality, but also butter of delicate aroma; and that it is 

 only a question of time when mixed cultures will be widely used in 

 I)lace of cultures of acidifying bacteria alone. But for the present it 

 is to be wished that we might more generally follow the example of 

 Denmark, and by taking advantage of the improved methods of butter- 

 making produce a pure and fine-flavored butter, which is possible with 

 the use of pure cultures of souring bacteria." 



The spontaneous souring of milk, G. Leichmann {Milch Ztg., 25 

 {189G), j\'o. 5, pp. 07-70). — The author refers to a previous paper by him- 

 self and to a recent one by C. GUnther and H. Thierfelder (E. S. R., 7, j). 806). 

 In his i)revious studies on 24 samples of milk of various origin, made 

 during summer, the souring was determined to be invariably due to a 

 single form of microorganism which did not agree with Hueppe's Bacillus 

 acidi lactici or with other described forms. The form found by Giinther 

 and Thierfelder is said to correspond to that found by the author, 

 although they x)ronounced it identical with Bacillus acidi lactici. The 

 author gives a preliminary account of continued studies during winter 

 on some 60 samples of milk from different localities. The same lactic- 

 acid bacillus as jireviously described was found in all the samples, and 

 in nearly all in such immense numbers as to convince the author that 

 it was the cause of the souring. In sterilized milk it produced optic- 

 ally active, dextro rotatory lactic acid, with traces of a volatile com- 

 pound giving the iodoform reaction, but no volatile acids or gas forma- 

 tion. A pure culture in milk in a breeding oven for 3 days used 0.65 

 per cent of the milk sugar present, and the increased acidity was equiva- 

 lent to 0.67 i)er cent of lactic acid. As no other acid was produced, it 

 is believed that the decomposition of the milk sugar by tlie bacillus was 

 as Schiitzenberger has suggested: 



