I 4 



MILK AND ITS HYGIENIC RELATIONS 



These figures were obtained from milk taken directly from 

 the cow. Out of forty-two samples examined, in two cases only 

 was a decrease in the number of cells obtained as a result of 

 heating. In all the other cases an increase was observed, which 

 varied from 12 per cent, (one sample only) to 1360 per cent, 

 increase in the number of cells observed in the heated samples 

 over the unheated. 



Similar results were obtained in the case of market milk, the 

 average increase per cent, being, however, considerably higher as 

 a result of heating, than in the case of the milk from a single cow. 



Campbell also showed that the analytical error is much smaller 

 in samples of milk which have been heated to 70 C. than in un- 

 heated samples. A number of examinations are given, of which 

 the following may be taken as typical : 



Campbell showed further, in a number of experiments, that the 

 temperature to which the milk is raised has a marked effect upon 

 the number of leucocytes found. Thus in one sample the following 

 counts were obtained : 



1 The smaller number is used as the basis in each case. 



