172 MILK HYGIENE 



careful, longer intervals may safely be permitted to 

 elapse between visits. After an inspector has gone over 

 his ground and has become acquainted with local condi- 

 tions, and the individuals, the question of frequency of 

 visits should be left to a larger extent to him. 



The number of inspectors required is of course in 

 direct proportion to the frequency of inspections. If a 

 single inspector could visit all of the dairy farms sup- 

 plying a given city in one year, about twelve inspectors 

 would be required to visit these farms each month. It 

 is estimated that the number of inspectors that would 

 be required to carry out an adequate system of dairy 

 farm inspection for the city of Philadelphia is about 20. 

 About 60 to 80 country inspectors would be required 

 for the city of New York. L. P.] 



For herds supplying " nurse yy milk " or " infants' 

 milk," decidedly rigid requirements must be made be- 

 cause, so far as possible, this milk must be so produced 

 that it can be used in its raw state by children and 

 invalids without any danger whatever. 



Therefore, dealers should not be permitted to sell 

 milk under these names if the herds are not under the 

 insi^ection of a public veterinary officer ; and the inspec- 

 tions should take place at least every fourteen days, 

 preferably every week. It must be required that ' ' nurs- 

 ery milk " shall come only from herds absolutely free 

 from tuberculosis {i.e., herds that are tested with tuher- 

 culin at least once every year, and to which only abso- 

 lutely healthy animals are allowed to be added), be- 

 cause the diagnosis of some dangerous forms of tuber- 

 culosis is often very difficult and, in the earlier stages, 

 even impossible, and because it has been proven impossi- 

 ble to prevent the occurrence of the dangerous forms 

 merely by the removal of animals in which tuberculosis 

 is clinically apparent. Besides, the definite requirement 



