78 DAIRY TECHNOLOGY 



Russell and Hastings, 1 Schroeder 2 and others have shown 

 that a temperature of 140 F., for 20 minutes, is sufficient 

 to kill tubercle bacilli in milk. Schroeder tells us that: 



" The simplest, the least expensive, and the most effi- 

 cient available expedient through which the public can be 

 protected against bovine tubercle bacilli and other viruses 

 that may be disseminated with milk is pasteurization." 



He also states that, until commercial pasteurization has 

 been placed under official supervision, home pasteurization 

 should be employed as the best solution to the milk problem. 



Inefficiency of pasteurization under commercial con- 

 ditions is usually due to ignorance or carelessness. The de- 

 gree of heat and the time of exposure that are necessary to 

 improve the keeping quality of milk also kill all pathogenic 

 organisms. The finding of contagious disease producing 

 germs in milk is an indication that the dealer has not even 

 accomplished his special object of improving the keeping 

 properties of his milk. The dealers, as well as the patrons, 

 suffer because of this lack of efficient pasteurization. 



The movement for the adoption of compulsory official 

 supervision of all milk for city supply is gathering momen- 

 tum and producing most satisfactory results. In cities 

 where such supervision is properly enforced, the pasteurized 

 milk can be relied upon. 



Laws and Ordinances Pertaining to Pasteurization. 

 There has been, during the past few years, considerable 

 legislation pertaining to pasteurization. New York City 

 has recently added the following rules to its sanitary code: 



i. Pasteurization must be carried out under a permit 

 therefor issued by the board of health, in addition to the 

 usual permit for milk. 



1 Outlines of Dairy Bacteriology. 



2 U. S. Dept. of Agr., Bu. An, Ind., An. Kept., 1909. 



