82 THE MILK SITUATION IN THE DISTRICT OF COLUMBIA. 



health officer, wisely consented to the postponement of insistence com- 

 pulsorily upon the test in the case of all herds located in Maryland, 

 Virginia, and elsewhere outside of the District of Columbia, fur- 

 nishing milk for consumption in the District, for such period of time 

 as the farmers may reasonably require to prepare themselves to meet 

 the conditions of the test and until the legislatures of the States of 

 Maryland and Virginia may have an opportunity to provide adequate 

 compensation for animals condemned. It is proposed by the com- 

 mittee that a period of two years might appropriately and advan- 

 tageously be arbitrarily fixed for the introduction of the test compul- 

 sorily among herds supplying milk for consumption in the District. 



The committee concludes its observations on this feature of its 

 investigations with the remark that the tuberculin test has been found 

 to be a more nearly infallible means for diagnosing tuberculosis than 

 any known agency for diagnosing other diseases of men and animals ; 

 and since it is the consensus of scientific thought that our dairy herds 

 can be freed from tuberculous cows by the systematic application of 

 the test and the segregation of aH reacting animals, the committee 

 recommends without hesitancy that the compulsory application of the 

 test to all animals furnishing milk to the District of Columbia be 

 required as rapidly as the exigencies of the situation will allow. 



VI. MAINTENANCE or Low TEMPERATURE. 



ESSENTIALITY OF TEMPERATURE NOT EXCEEDING 50 F. 



Since the bacterial content of milk depends, (1) upon its age, (2) 

 the number of bacteria contained initially and proliferated, or in- 

 troduced during the process of milking and handling, and (3) the 

 temperature at which the milk is kept, cleanly milk, quick cooling, 

 and the shortest practicable time between milking and consumption 

 are important factors in providing a pure milk supply. Not only 

 should the milk be cooled immediately, which has been proved be- 

 yond peradventure to be an exceedingly important requirement, but 

 in order to prevent the rapid multiplication of germ life, it should 

 be kept cool until consumed. This necessitates the maintenance of 

 low temperature in hauling to the depot, while waiting at the ship- 

 ping point, during transportation on the cars, and while being held 

 and distributed by the city dealer. In the winter months, the low 

 atmospheric temperature renders the keeping of milk below 50 F. 

 easy of accomplishment, but in the warm season to maintain the 

 desired temperature involves the use of efficient methods of refrigera- 

 tion on the part of the dairyman, the transportation company, the 

 wholesale distributer, the retail dealer, and, finally, on the part of the 

 consumer. 



The rapid cooling of milk after it has been drawn, to a temperature 

 of 45 F., and the maintenance of that temperature until the time of 

 consumption, not only prevents the multiplication of the bacterial 

 flora contained in the milk when drawn from the cow, but actually 

 tends to diminish the number of bacteria. 



So eminent an authority as Dr. William H. Park, of New York 

 City, gives testimony to the effect that milk rapidly and sufficiently 

 cooled remains almost unaltered chemically and bacteriologically for 



