GEORGE W. PUTNAM 425 



deaths which would have otherwise resulted from the use of contaminated raw milk. 

 Only recently we have had a forceful reminder of the sickness and death which can 

 be spread through contaminated raw milk in the example of the Montreal typhoid 

 epidemic of 1927,' the largest epidemic of this disease in many years. A frank dis- 

 cussion of defects preventing proper pasteurization should not be interpreted as be- 

 littling in the least the role that it has played in the past, but rather as an effort to 

 arrive at means of insuring that commercial pasteurization will give more complete 

 protection against milk-borne diseases. 



The publication in February, 1925, of the report^ on extensive investigations of 

 commercial pasteurization by North and his collaborators marked a milestone in 

 the advancement of milk pasteurization. These studies, known as "The Endicott 

 (N.Y.) Experiments," are the most extensive series of tests on the destruction of 

 pathogenic bacteria in commercial milk-pasteurizing equipment that has ever been 

 undertaken. Although their primary purpose was to establish a safe temperature for 

 pasteurization by the holding method, the main value to milk sanitarians was that 

 they revealed conclusively that mechanical and engineering defects prevented proper 

 pasteurization of all the milk. The finding of living tubercle bacilli in samples of 

 milk collected during numerous test runs on commercial pasteurizers in the Endicott 

 experiments (first series) was proof that the defects in the equipment prevented com- 

 plete destruction of these organisms under conditions of time and temperature in 

 the main body of the milk which laboratory studies indicated should accomplish this. 



The general conclusion made by the authors following the first series- of tests 

 with pathogenic bacteria states in part: 



The bacteriological examinations confirm the results of the engineers' observations. The 

 engineers had noted defects in the principles, both of the construction and equipment, of all 

 three types of pasteurizers which it was impossible to overcome by even the most skillful 



supervision of the methods of operation Everything considered, however, it is proper 



to observe that the results plainly indicate the importance of better engineering in the build- 

 ing and equipment of these representative types of commercial pasteurizers if they are to be 

 accepted with confidence as proper safeguards of public milk supplies. 



It is of interest to note that many of the defects emphasized in this publication 

 were brought to the attention of the public-health profession in the 1920 report^ of 

 the Committee on Milk Supply of the Public Health Engineering Section, American 

 Public Health Association. As a result of these revelations, a comprehensive engineer- 

 ing program for the correction of defects in pasteurizing equipment was organized 

 in Chicago in March, 1926, by Dr. Herman N. Bundesen, commissioner of health. 

 An outline of this program was recently reported by the writer.^ Coincident with this, 

 the United States Public Health Service established its pasteurization-equipment 

 testing station in Chicago, thus effecting a joint research and administrative program. 



' Am. J. Pub. Health, 17, 783. 1927. 



' North, C. E., Park, W. H., Moore, V. A., Rosenau, M. J., Armstrong, C, Wadsworth, A. B., 

 and Phelps, E. B.: Commercial Pasteurization, Pub. Health Bull. 147. Feb., 1925. 



3 Committee on Milk Supply of the Public Health Engineering Section: Pasteurization of Milk, 

 Am. Pub. Health Assoc. Rep. Aug., 1920. 



■» Putnam, G. W.: Am. J. Pub. Health, 17, 121. 1927. 



