GEORGE W. PUTNAM 435 



A large number of health officials have demanded 145° F., while the milk dealers, 

 supported by a number of scientists, have maintained that 142° F. is a safe tempera- 

 ture. In 192 1 the Borden Farm Products Company of New York engaged Dr. 

 Charles E. North to organize and conduct research work on this problem. The second 

 series of these tests, previously referred to as "The Endicott Experiments,"' served 

 to demonstrate that the mechanical defects in commercial pasteurizing equipment 

 prevented the satisfactory destruction of pathogenic bacteria in milk, even when a 

 temperature of 145° F. was used. Later tests on improved equipment gave more 

 satisfactory results. 



The author's final conclusion states in part: "The bovine tubercle bacilli used 

 were destroyed in some tests in three types of improved commercial pasteurizers at 

 138° F. for thirty minutes. The temperature and time for pasteurization contained 

 in the milk regulations of the cities of New York, Philadelphia, Baltimore, and many 

 other large cities, and the regulations of the states of New York, Connecticut, and 

 others, which is that 'milk or cream shall be heated to a temperature of at least 142° 

 F. and held at such temperature for 30 minutes or more,' provides an adequate mar- 

 gin of safety, and is recommended as a proper standard for the definition of pasteuri- 

 zation by health authorities." Instead of settling the controversy as to the proper 

 temperature for pasteurization, this admirable report served rather to emphasize the 

 engineering defects preventing proper pasteurization in commercial equipment. 



The following difficulties in the enforcement of present-day legal definitions of 

 pasteurization regardless of the temperature standard are pointed out by Frank, 

 Moss, and LeFevre in a recent article :' 



1. Some definitions which specify by intent a recording thermometer temperature 

 but do not specify approved apparatus permit the use of defective equipment not in- 

 suring proper pasteurization ; those specifying approved apparatus cannot be general- 

 ly enforced, because of lack of official information to serve as a basis for approval. 



2. Those definitions which require that "every particle of milk" be exposed to 

 the temperature specified imply that the enforcing health officer has the necessary 

 knowledge or information available as to which equipment can be approved as ac- 

 complishing this. 



3. That some definitions would, if strictly enforced, cause partial or complete de- 

 struction of the cream line on the milk, and consequently interfere with the sale of 

 pasteurized in competition with raw milk. 



They suggest the re-wording of existing definitions into one of the following forms: 



1. Pasteurized milk is milk which has been heated to at least [ ° F.] and held 



thereat for at least [ ] minutes as indicated by its recording device, provided that no 



apparatus shall be used which has not been approved by the [accepted agency making the 

 ofticial tests] for use under this definition and provided that all apparatus shall be operated 

 in accordance with the directions recommended by the [accepted agency making the official 

 tests.] 



2. Pasteurized milk is milk every particle of which has been heated to 140° F. and held 

 thereat for 30 minutes in apparatus approved by the health officers, provided that the re- 



' See p. 425. 



'Frank, L. C, Moss, F. J., and LeFevre, P. E.: Am. J. Pub. Health, 17, 131. 1927. 



