538 MILK 



costs 0.313 cent per gallon to pasteurize milk. Safety from dis- 

 ease is surely worth this additional cost. 



In certain quarters the cry is raised that pasteurization is not 

 always carried out conscientiously. This may be true, but can- 

 not be used as an argument against the efficiency of the process. 

 The dishonesty or ignorance of some individuals does not vitiate 

 the principle of pasteurization. In the large cities of this coimtry 

 pasteurization is commonly practised, as shown by the following 

 figures given by Ayers: 



EXTENT OF PASTEURIZATION OF MILK IN CITIES IN THE UNITED STATES 



Number of More than 11 to 50 to 10 



cities 50 per cent. per cent. per cent. None 



answering pasteur- pasteur- pasteur- paateur- 



Population of cities. question. ized. ized. ized. ized. 



More than 500,000 9 7 2 



100,001 to 500,000 40 12 20 6 2 



75,001 to 100.000 19 5 8 4 2 



50,001 to 75,000 30 4 15 6 5 



25,001 to 60,000 78 13 31 12 22 



10,001 to 25,000 168 10 40 18 100 



Total 344 51 116 46 131 



PEOPORTION OF TOTAL MILK-SUPPLY PASTEURIZED IN CERTAIN CITIES' 



Percentage Percentage 



City. pasteurized. City. pasteurized. 



Boston.Masa 80 Philadelphia, Pa 85 



Chicago, III 80 Pittsburgh, Pa 95 



Detroit, Mich 57 St. Louis, Mo 70 



New York, N. Y 88 



The same author states that in 1912, of 231 milk plants ex- 

 amined, 99 per cent, of those using the holder process, pasteurized 

 at the proper temperature, while among those using the flash 

 process 57 per cent, employed temperatures high enough to give 

 satisfactory results. The holder process is constantly gaining 

 favor, and at the present time milk is probably more efficiently 

 pasteurized than the above figures indicate. Every new process 

 must have time for development and attainment of perfection. 



Instruction of the public as to the meaning of pasteurization 

 should receive more attention than heretofore. The consumer 

 must not be allowed to believe that pasteurized milk needs less 

 care than raw milk, and he should know that pasteurized milk 

 means milk heated to a degree which destroys infectious material. 

 Otherwise a feeling of false security may be created. This prin- 

 ciple also appHes to certified milk, as has been pointed out. 



Whether milk should be pasteurized in the home is a ques- 

 tion which presents itself. In European countries milk is com- 

 monly boiled, but this is a different matter from pasteurization. 

 It is easy to know when milk is boiling, but to know when it has 

 reached a certain temperature means the intelligent use of a good 

 thermometer. This thermometer should always be inserted into 



' In the small cities the percentage of milk pasteurized is much lower. 



