54 THE DAIRY OF THE FARM. 



maintenance of this relaxing condition of the milk. And 

 he also remarks that a period of rest from milking before 

 the next birth is necessary in order that time be given to 

 the milk- secreting organs for the provision of the material 

 to which the altered state of the milk is then due. How 

 very much the milk is thus altered, is shown by analyses 

 by Henry and Chevallier, who found in the first milk of the 

 cow, ass, and goat respectively 15' 1, 11*6, and 24 '5 per 

 cent, of casein : differing enormously from the figures given 

 above. The following table gives the results of numerous 

 analyses of ordinary cow's milk : 



Of these, No. 1 is the average of 10 analyses, by 

 Boussingault, of milk from cows about 200 days after 

 calving, and fed upon the whole on rather poor rations. 

 No. 2 is the average of 8 analyses, by Playfair, of autumn 

 milk, from a shorthorn cow, whose period of calving was 

 not known ; she was fed on rich food. No. 3 is another 

 by Playfair, "the average of several analyses taken when 

 the cow was in the field." No. 4 is an analysis by Henry 

 and Chevallier : 5 is by Dr. K. D. Thomson * of milk 

 from grass-fed cows ; and 6 is the average of two samples. 



Thomson on the Food of Animals. Longman. 



