THE MILK CONTRACTOR 269 



155F., and even less at higher temperatures adversely affects the cream 

 line. So, despite the fact that in pasteurizing milk by this process, a tem- 

 perature of 176F. must be used to kill all disease germs, because the cir- 

 culating milk is not heated equally since that in contact with the heating 

 surfaces of the machines moves more slowly than the rest, in practice, 

 much lower temperatures were employed. The pasteurizers were built 

 so that the speed at which the milk passed through them could be con- 

 trolled by the operator and pasteurizing was actually done at tempera- 

 tures ranging between 140 and 165F. Indeed, the tendency was toward 

 even lower temperatures; Dr. Evans stated in 1910 that prior to the 

 enactment of the latest law governing pasteurizing the average maximum 

 of pasteurization in the city of Chicago was 128F. Pasteurization of 

 this sort at these temperatures did not protect the public from disease, 

 and it is manifest that dealers were not greatly concerned in this phase of 

 the subject but were employing pasteurization solely to delay the souring 

 of their milk. It did this so effectively, that without cooling, it would 

 keep sweet till delivered to customers, hence not a few dealers regarded 

 pasteurizing as a means of cutting down ice bills. 



Moreover pasteurization was misused in another way by contractors, 

 in that milk sometimes received two or more pasteurizations before it 

 reached the consumers. It was pasteurized at plants in the country and 

 was repasteurized on its arrival in the city and some dealers gave part of 

 the milk another pasteurization, for that which came back undelivered on 

 the wagons was heated again and sent out to customers. 



A further abuse was, that in some plants, particularly those in the 

 smaller cities, little attention was paid to the care of the pasteurizing 

 machines, so that they became very dirty and the milk ill-flavored and of 

 poor keeping quality. 



Finally, pasteurization was used covertly; one large firm in New York 

 City used the flash process for 5 years before it was compelled to announce 

 to its customers that it was selling pasteurized milk. In 1906, the New 

 York City Board of Health forbade clandestine pasteurization and in the 

 spring of 1910 had a law passed fixing the time and temperatures at which 

 milk must be pasteurized. Laws of the same sort were soon passed by 

 other cities. The temperature scales decreed by New York and Chicago 

 are given in Tables 81 and 82. 



While this commercial development of the flash process was going on 

 the holder process was attracting the attention of scientific investigators 

 and its use at different temperatures and for various time periods began 

 to be advocated by them. Even after its superior merits were demon- 

 strated and laws tending to bring about its adoption were passed it was 

 regarded with disfavor by contractors in general and they moved with 

 extreme slowness in altering their plants for its installation. Its first 

 cost was greater than that of the flash process and where the latter was 



