44 MILK [iv 



carried out by Boussingault, will illustrate that there 

 is a steady increase in the total solids during the 

 whole period of milking. In this experiment the 

 milk drawn from the cow's udder was divided into 

 six consecutive portions and analysed. The follow- 

 ing were the results found : 



(1) (2) (3) (4) (5) (6) 



Solids . 10-47 10-75 10-85 11-23 11*63 12-67 



Fat . 1'70 1-76 2'10 2'54 3-14 4-08 



Solids not Fat 8-77 8'99 875 8-69 8'49 8'59 



From the above figures, it will be seen that the 

 increase is limited to the fat, the solids not fat 

 remaining practically uniform. A view which was 

 formerly held to explain this was that the milk 

 underwent a sort of creaming process in the cow's 

 udder ; the last drawn being the surface layer of the 

 milk, and therefore richer in fat than that first drawn. 

 In view, however, of our present knowledge of the 

 structure of the udder, it is not likely that any such 

 creaming process could take place. The explanation 

 first given commends itself as a far more probable one. 

 Difference in Morning and Evening Milk. 

 If, in the case of a cow milked twice a day, the 

 intervening period between each milking is the same, 

 and if other conditions are similar, it may be said 

 that there will be approximately no difference be- 

 tween the morning and evening milk, both as regards 

 quantity and quality. If, on the other hand, the 



