556 PHYSIOLOGY AT THE FARM. 



the albumen of the serum of the blood can be changed to 

 caseine by the addition of caustic potash ; but the conversion 

 of the albumen and fibrine of the blood of the cow into caseine 

 after parturition bears too much the character of the processes 

 termed vital to permit us to expect that any mode of feeding 

 or management could do much towards increasing the propor- 

 tion of caseine in the milk of the dairy cows. Nevertheless 

 the subject is worthy of attention. The proteine compound 

 that comes nearest to caseine is legumine, the principle exist- 

 ing in the seeds of the leguminous order of plants, to which 

 beans, pease, and the artificial grasses belong. Experiments 

 on the proportion of caseine in the milk of animals fed largely 

 on such food, as compared with its proportion in those fed on 

 other kinds of food, deserve to be set on foot. Beans are a 

 favourite food with dairymen for their cows, chiefly in the form 

 of bean-meal. The effects on the milk produced by food con- 

 taining a more than usual proportion of potash should also be 

 inquired into. Playfair says " Potash is perfectly indispensable 

 to the formation of milk ; indeed this alkali seems to be the 

 means by which the albumen in the body of the cow is 

 rendered soluble, and consequently converted into caseine." * 

 The sugar and butter contained in milk suggest the use of 

 mangold-wurzel and linseed-meal in the food of the milch cow. 

 The following analysis is the average of several experiments 

 made on the milk o f the cow in the field : 



Caseine, ...... 4.0 



Butter, . . . . . .4.6 



Sugar of milk, . . . . .3.8 



Ashes, . . . . . . 0.6 



From 100 parts of milk, the produce of two cows, the follow- 

 ing proportions of salts were procured : 



* ' English Journal of Agriculture,' vol. iv. p. 246. 



