244 CIVIC BIOLOGY 



Clean milk. For many, possibly for all, communities 110 better health- 

 conservation work could be undertaken than solving, each member of 

 the class for his own home and the whole class for the home commu- 

 nity, the problem of safe and clean milk. Milk is safe when all disease 

 germs are kept out of it, and it is clean when free from filth of all sorts, 

 usually indicated by numbers of other bacteria. As secreted by healthy 

 cows, milk is pure, and by observing hospital-operating-room precau- 

 tions it can be kept so. l Von Behring's statement that milk should not 

 -1>e used for infant feeding if it contains more than 1000 bacteria per 

 cubic centimeter is rarely lived Tip to. Boston's standard of purity 

 (which Spargo thinks is worse than no standard at all) allows 500,000 

 bacteria per cubic centimeter, arid " certified milk " may run as high as 

 10,000 bacteria per cubic centimeter. Secure copies of specifications for 

 local certified dairies. 2 If possible, have a committee of the class, or 

 each member, work up the technique of making the bacterial count and 

 examine local milk supplies. 8 



We have been too long scoring dairies according to buildings and 

 equipment, and nothing could be more convincing for the truth of 

 Dr. North's contention that dirty milk is 90 per cent due to dirty or 

 ignorant dairymen than his demonstration in ten Kelton dairies. Ten 

 trained Oxford dairymen were shipped over to Kelton in time to do the 

 evening milking in ten of the dirtiest Kelton dairies, with the result 

 shown on the next page : bacteria in the milk reduced from millions 

 to less than 10,000 per cubic centimeter, in all but Xo. 0, a most in- 

 structive exception. 4 



Four things necessary to production of clean milk : 



1. Milking with dry hands into covered pails. 



2. Proper washing and sterilization of milking pails and milk cans. 



3. Cooling milk by placing cans in tanks of cold water or ice water. 



4. Regular laboratory testing of milk for bacteria, and payment 

 based on the laboratory tests. 



Pasteurized milk. Dangerous milk can be made safe by heating to 00 

 for twenty minutes, and this does not seriously injure its nutritional 

 value. This treatment kills all non-spore-forming disease germs of 



1 Rosenau, The Milk Question, p. 73. (Tells how Mr. S. L. Stewart, New- 

 burgh, New York, produces milk free from bacteria.) 



2 Rosenau, Requirements for "Certified Milk," pp. 151-160. 



3 Russell and Hastings, Experimental Dairy Bacteriology, p. 122. 



* North, " The Dairyman versus the Dairy, 1 ' American Journal of Public 

 Health, Vol. V, pp. 510-525. 



