832 EXPERIMENT STATION RECORD. 



swiiie plague bacteria and bog-cholera bacilli, with results similar to 

 those obtained with tubercle bacilli, rabbits inoculated with the skim 

 milk and cream dying of the respective diseases. 



Experimeuts were also made with the aid of a "hand centrifugal 

 machine," using milk to which had been added cultures of tubercle 

 bacilli, hog cholera, and swine plague. The results showed that the 

 bacteria were not entirely removed by this tieatmeiit and that the milk 

 and cream contained suflicient germs to cause the diseases in animals. 



"The results of the experiments recorded in the precediD<>; pages show that the 

 physical conditions involved in the mechanical treatment of milk do not allow the 

 deposition of all bacteria in the sediment. Many of the hacteria were carried over 

 into the skim milk and into the cream. With this fact before us it is easy to nnder- 

 stand that the butter made by the use of the separator from infected milk might 

 contain the specific bacteria."' 



An experiment is recorded in which butter was made from milk to 

 which a few cubic centimeters of a culture of hog cholera had been 

 added, the cream being raised by a separator and the butter made in 

 the usual way. 



" Four days afterwards a rabbit was inoculated beneath the skin with 0.2 cc. of 

 the buttermilk, and another with a piece of butter about the size of a pea. These 

 rabbits died of hog cholera in 7 days." 



In conclusion, the author believes that these experiments show that 

 disease may be transmitted through butter and skim milk, and recom- 

 mends as a remedy the pasteurization of milk intended for butter 

 making. 



On the bluing of cheese, A. Hehle {MolJc. Zig. Berlin, 1S96, Oct. 

 31; ahs. in Milch Zig., 2'j {1896), IS'o. 46, p. 755).— The cause of this 

 trouble at a cheese factory under the author's supervision was finally 

 traced to one herd which furnished milk to the factory. An investiga- 

 tion showed that it was the custom to feed the cows in the morning 

 very sour beet diffusion residue which had stood in iron barrows over 

 night. It is believed that the iron taken ui^ by tlie acid was transmit- 

 ted to the milk, and was the cause of the cheese becoming blue. 



The author finds that keeping milk in rusty cans does not always 

 result in the trouble, but only when the milk is sour. To recognize iron 

 in milk about 5 cc. of milk is treated with a few drops of tannin solu- 

 tion (5 gm. tannin in 150 gm. water). If the milk turns bluish it is not 

 used for cheese making. 



The manufacture and consumption of cheese, H. E. Alvord 

 ( U. 8. Dept. Agr. Yearbook 1895, j)}). 453-474, Jig. 1, dgms. 2). — This article 

 is devoted principally to a discussion of the production of cheese, the 

 decline in the exportation of cheese, means by which the consumption 

 of cheese in this country miglit be increased, the manufacture of skim 

 cheese and tilled cheese in the United States, and the necessity of clas- 

 sifying and branding cheese as a safeguard to the consumer and to the 

 producer of high-grade cheese. 



