208 BACTERIA, YEASTS, AND MOLDS 



Milk from Ordinary Milkmen. The milk from the or- 

 dinary milkmen varies very greatly in quality, sometimes 

 being of a very high quality and sometimes very poor. 

 There is no way in which the consumer can tell by look- 

 ing at the milk whether it is good or not. Public statutes 

 and public officials endeavor to guard the milk supply for 

 the benefit of the public, and have so far succeeded that in 

 general the watering and skimming of milk are rare. Chemi- 

 cally, market milk is usually well standardized ; but cleanh- 

 ness, freshness, and general wholesomeness are more difficult 

 to guarantee by any form of public inspection. As a result 

 much filthy milk, quite unfit for consumption, is constantly 

 sold. It is certain that a considerable part of the deaths 

 of infants is directly caused by old or filthy milk. 



A method of meeting this difficulty has now been adopted 

 in many progressive communities by a system of grading. 

 This consists of having each bottle labeled with a large 

 letter which indicates its grade. The grades adopted are 

 A, B, and C. The exact meaning of these grades varies 

 slightly in different localities, but in general they signify 

 the following: Grade A is milk of the best quality, pro- 

 duced in a cleanly fashion, free from disease germs and 

 fitted to be used raw as an infant food. It may be sold 

 either raw or pasteurized, but must be marked to show 

 whether or not it has been submitted to pasteurization. 

 In many communities Grade A pasteurized milk is not 

 sold, as there seems little object in taking expensive pre- 

 cautions to prevent contamination of the milk if it is to be 

 pasteurized and the disease germs in it thus killed. Grade B 

 is milk of an equal food value, but the production of which 

 has not been surrounded by quite so great precautions. 



