KEGULATION OF PRODUCTION 167 



never just alike at different times or places. The lab- 

 oratory examination of a milk sample gives some infor- 

 mation as to the condition of that sample and, by infer- 

 ence, as to the conditions under which a certain quantity 

 of milk was produced and handled on a given day. But 

 some of the contaminations of milk that are most dan- 

 gerous cannot be detected by routine examinations in 

 the laboratory, if at all, excepting by their effects on the 

 consumer ; among such contaminations are those caused 

 by the specific organisms of tuberculosis, typhoid fever, 

 diphtheria, scarlet fever and the materies morbi of 

 many diseases of cows. Therefore, so far as the pre- 

 vention of the infection or pollution of milk is concerned, 

 it is more important that the milk be produced under 

 such conditions that contamination is well guarded 

 against than to know the condition of a certain quantity 

 that has already been used. 



The laboratory examination of milk is, however, of 

 much value in checking and controlling the accuracy of 

 farm and herd inspections, which inspections are de- 

 signed to prevent infection and pollution, while the lab- 

 oratory discovers contaminations that have already 

 occurred. 



The author's position on this general subject is quite 

 analogous to the opinion that is now held by sanitarians 

 in regard to the way in which the purity of the water 

 supply should be obtained and insured ; that is, by clean- 

 ing and guarding the source. 



It is well to lock the stable door before the horse is 

 stolen. But it has, thus far, been impossible in America, 

 excepting in a few isolated instances, to impress the 

 public sufficiently to lead to the establishment of a sys- 

 tematic inspection of the sources and methods of hand- 

 ling and transporting milk. Eeasons for this condition 

 are, the paucity of specially trained men for this ser- 



