298 REPOllT OF OFFICE OF EXPERIMENT STATIONS. 



accomplish this is certainly desirable on account of the chanr^es pro- 

 duced ill miliv hy a hi<xh de<j^ree of heat and the prol)ability tiiat these 

 chan<;es lessen the nutritive value of the [)roduet. In this connection 

 the investigations of Farrin^ton, Kussell, and Hastings" are of value. 

 They made practical tests of pasteurization at 140° F., the tempera- 

 ture at which the tubercle bacillus was found by Theobald Smith to 

 be killed when exposed for 15 to 20 minutes under conditions pre- 

 venting the formation of a film upon the surface of the liquid. These 

 conditions were secured by agitation of the milk in a closed receptacle. 

 The character of the milk was api)arently unaffected by pasteuriza- 

 tion at 140° F., while tubercle bacilli of bovine origin were destroyed, 

 as determined by innoculation experiments with guinea pigs. These 

 authors, therefore, conclude, as the result of considerable experience, 

 that by heating milk for twenty minutes 140° F. in closed i)asteur- 

 izers one may be certain that the tubercle bacillus will be destroyed 

 and the milk uninjured in any way. 



PRESERVATIVES. 



Some attention has been paid to the use of preservatives in market 

 milk. Doane '' has reviewed the literature and conducted experi- 

 ments with animals on the effect of certain preservatives, and Chester 

 and Brown ^ have made experiments to determine the effect of for- 

 maldehyde on the development of bacteria in milk. However, the 

 experimental work at the stations seems too limited to warrant any 

 very positive conclusions on this subject. 



GENERAL ARTICLES. 



Aside from the station publications reporting original work, of 

 which some are previously noted, many bulletins have been issued 

 which treat in a more or less popular numnei- of the most approved 

 methods of producing and handling milk. Brief summaries of the 

 contents of a few of these follow : 



Alabama College Station Bulletin 07, Dairy and Milk Inspection, 

 by C. A. Cary, treats of the necessity of milk inspection, the testing 

 of dairy herds for tuberculosis, the feeding and watering of cows, 

 the location and construction of dairy buildings, impurities in milk, 

 the composition and analysis of milk, the various forms of adultera- 

 tion, including preservatives, bacteria in milk, the transmission of 

 typhoid fever and other diseases by means of milk, the disinfection of 



a Wisconsin Sta. Rpts. 1890, i». 12!); 1000. p. 147; 1901, p. 185. 

 6 Maryland Sta. Rul. 8G. 

 c Delaware Sta. Bui. 71. 



