DEVELOPMENT OF CITY MILK SUPPLY PROBLEMS 49 



There can be no question regarding the relative ease and 

 a curacy with which the above outlined examinations will give 

 the facts regarding the food value, freedom from germs of 

 infectious diseases, and cleanliness of a sample of milk. How- 

 ever, there is not the same agreement regarding the possibility 

 of determining the keeping quality. There are at present no 

 means available for quickh^ measuring the keeping quality 

 of milk exc?pt in samples which are rapidly approaching an 

 undesirable condition. In such samples titratioa. \if the 

 acidity may indicate their condition and ,in the, case, ,of jyi- 

 pasteurized milk a microscopic examination J id'^evfen'' ifaftre 

 useful. However, the results from both such examinations 

 of some milk samples may seem favorable and still the milk 

 may not remain sweet for tw T enty-four hours under household 

 conditions. 



In the absence of any test which will immediate^ yield the 

 desired information in the case of pasteurized milk, recourse 

 may be had either to the bacterial count or to the observation 

 of a sample of the milk itself. Since the question at issue is 

 the ability of the milk to remain sweet and in satisfactory 

 condition for twenty-four or at most forty-eight hours, this 

 fact can be determined from the sample of the milk itself 

 quite as quickly as the bacterial count can be determined from 

 the standard plates. The examination of the sample has the 

 added advantage that it does not require as extensive equip- 

 ment nor as delicate manipulation. Most important of all, 

 it gives precisely the information desired while the bacterial 

 count even when accurately determined must first be trans- 

 lated before it can be of service. 



Following the plan above outlined it is practicable to collect 

 samples of the milk as delivered to the consumer and from 

 the examination of such samples, supplemented by some 

 inspection of pasteurization plants, determine the food value, 

 healthfulness, cleanliness, and keeping quality of the milk 

 supply. 



