FACTS CONCERNING MILK 173 



the same milk pail and mixing tank, some of the difficulties in estab- 

 lishing a just, arbitrary standard may be appreciated. 



It is difficult to induce the public to realize that refined methods 

 of analysis, the more careful attention to breeds and breeding, the 

 great difficulty of supplying from considerable distances, the ever- 

 increasing urban demand, the introduction of centrifugalization and 

 other important considerations have entirely changed the complexion 

 of the milk problem within a very recent period. 



Many of us do not realize that much of the milk consumed in our 

 large cities is taken from herds kept as far as 300 miles or more from 

 the consumer, and when it is delivered to him is frequently forty-eight 

 hours old. The problems surrounding the transportation of such milk 

 in the summer season may be in part appreciated when we know that 

 the presence of 5,000 bacteria to the cubic centimeter is considered 

 a reasonably low count and that under favorable conditions this number 

 is capable of doubling by geometrical progression every half hour. 



Samples of commercial milk taken in New York city recently 

 showed 35,200,000 bacteria to the cubic centimeter; London, 31,888,- 

 000; Washington, 22,134,000. That seventy-eight typhoid germs in 

 one cubic centimeter of milk increased in seven days to 440,000,000 

 furnishes an illustration of the possibilities in this direction, and when 

 one realizes that one cubic centimeter is equivalent to about sixteen 

 drops, some idea may be gained of the bacterial population of much of 

 the milk we drink. 



Milk removed properly from a perfectly healthy cow, and kept in 

 receptacles previously sterilized, contains practically no bacteria, and 

 may at a low temperature be -preserved for days without material 

 change. When, however, these precautions are not observed the results 

 are as above indicated. Not all these germs are harmful, but many 

 varieties are exceptionally prejudicial to the health of children. Each 

 of 500 epidemics recently investigated, including typhoid fever, scarlet 

 fever and diphtheria were found to be caused by contaminated milk. 

 That 11 per cent, of milk samples examined from Washington con- 

 tained tuberculosis germs need not be considered as exceptional and 

 can be verified by the examination of data of a similar nature from 

 other cities. And when we understand that the milk supply of New 

 York city, for example, is derived from the product of 35,000 farms 

 and shipped from 700 creameries located in six different states, it is 

 easy to appreciate some of the difficulties surrounding the protection of 

 the community from the sources of infection contained in milk. 



In recent years the prominence given to tubercular disease in cattle, 

 with the consequent appearance of the tuberculosis germ in the milk 

 of such cattle, has entirely overshadowed the importance of certain 

 other diseases in cows, likewise accompanied by the presence in the 

 milk of cows so suffering of enormous numbers of bacteria charncter- 



