412 MILK 



appeals to the consumer because the layman is still under the im- 

 pression that disease follows the very presence of bacteria and, 

 therefore, is frightened at the mention of large numbers. How- 

 ever, there is little evidence of the injuriousness of the bacteria 

 and their products commonly occurring in milk. The grading 

 of the New York City Board of Health, according to which 

 Grade B milk may contain 1,500,000 bacteria before pasteuriza- 

 tion, shows that reliance is placed on pasteurization as a destruc- 

 tive agent. It is also interesting that the belief in the respon- 

 sibility of bacterial products for high infant mortality is losing 

 ground. 



A bacteriologic examination should not be compared with a 

 chemical analysis. The latter is exact; the former not. Results 

 of analyses of the same substance by different chemists are in 

 close agreement, while those of bacterial examinations vary, 

 sometimes within wide limits. It is possible, therefore, to draw 

 more definite conclusions from chemical analysis than from bac- 

 terial examination. It is not usually difficult, for example, to 

 detect some definite poison by chemical methods, but no bac- 

 teriologist would presume to state that a specific disease germ is 

 absent from milk because he cannot find it. 



A great deal has been said and written about the means of 

 reducing the bacterial content of milk, but instructions of such 

 nature have not infrequently been based on theory rather than 

 knowledge. Reference has been made in a previous chapter to 

 the research of Harding and his co-workers, who have shown that 

 the stable air and barn conditions need be of little influence on 

 the bacterial content of milk if due care is exercised in other 

 directions. It seems that demands have been made on the dairy- 

 man which were not justified by scientific research and that, 

 therefore, energy and money have sometimes been uselessly ex- 

 pended. 



All foods should be sold and served under cleanly and decent 

 conditions; more than that, the food itself should be as free as 

 possible from filth or the results of filthy habits of those produc- 

 ing and handling it. High bacterial counts mean one or more of 

 three things: 1, filthy production'; 2, high temperature during 

 transportation, and 3, old milk. But milk with low bacteria 

 content is not necessarily fresh, nor is milk with large numbers 

 necessarily stale. Still such is the interpretation sometimes given 

 according to established bacterial standards. 



To sum up, bacterial examination is of immense importance 

 as a guide to inspectors and as a control of supplies. But it does 

 not justify the recommendation or condemnation of milk without 

 the benefit of inspection. The bacterial count simply shows that 



