No. 4.] GRADING OF MILK. 175 



period of time during which the milk is heated, and these 

 report blanks are regularly placed in the hands of the board of 

 health, and none of the operators can tell what minute the 

 health inspector is liable to come in and supervise the plant. 

 We have found it very practical not only to supervise the raw 

 milk but also the process of pasteurization. 



Mr. BiXBY. If the raw milk is clean, is pure, is free from 

 disease and is guaranteed that way, isn't that raw milk better 

 than pasteurized milk? 



Dr. North. The raw milk is not guaranteed free from 

 disease by anybody. No health officer assumes that he is 

 able, by any amount of supervision, to prevent accidental 

 disease from the cow or accidental disease from the dairy 

 employee, and it is because no veterinarian can tell when a 

 cow is going to have an udder inflammation, and no physician 

 can tell when a dairy employee is going to have a throat 

 inflammation, that we have to pasteurize. 



Mr. Polk. I want to ask what the cost would be to a farmer 

 to pasteurize milk. 



Dr. North. Well, I know of one machine that he could get 

 for $50 that would handle the thing in first-class style. 

 Mr. Polk. And the farmer could do the work himself? 

 Dr. North. Yes. And I have seen some home-made 

 machines that did not cost more than $10, in which a man 

 did it at home. 

 Mr. Richardson. How much does it cost for operation? 

 Dr. North. The cost for operation of course depends on the 

 volume. The large milk dealers of New York have estimated 

 the cost of pasteurization at anywhere from a quarter of a 

 cent, which is the highest I have ever heard them say, down 

 to a tenth of a cent a quart, which is the lowest I have ever 

 heard a large dealer say. It is only a question of the farmer's 

 expenditure of his own time in pasteurization and the cost 

 of the steam heat or hot water, as the case may be. 



Mr. Potter. I should like to ask the doctor if pasteuriza- 

 tion would not stop the spread of tuberculosis among young 

 cattle. 



Dr. North. In Denmark they have a law requiring the pas- 

 teurization of all skim milk returned from creameries. That was 



