140 



chemical union entirely different from water which is merely 

 mixed with that substance, and we may argue by analogy that 

 there may be a similar two-fold condition of water in vegetable 

 substances. 



Whether this be so or not, the fact remains that a 

 vegetable as grown acts very differently as food to that vegeta- 

 ble firstly dried and subsequently mixed with an amount of 

 water equal to that which had been taken away. After a care- 

 ful consideration of the feeding experiments hitherto conducted, 

 it seems to me that the succulent foods which have contained 

 the greatest portion of water have proved the most valuable for 

 dairy cattle, and this is apparently the chief cause why in the 

 experiments of Mr. I. N. Edwards, and subsequently of Sir 

 John Lawes and Dr. Gilbert, mangels have proved superior to 

 silage. In dry matter the two diets were closely similar, but 

 the mangels contained 80 pounds of succulent water, the silage 

 only 40 pounds. 



In order to comprehend the further development and other 

 aspects of this subject, it is necessary to consider the organ of the 

 secretion of milk. Unlike most other organs of secretion, it 

 appears to allow substances taken as food to materially influence 

 the composition and properties of its secretion. Thus coloring, 

 tasting, and smelling substances find their way with more or 

 jess rapidity from the organs of digestion into this secretion. 

 The water which dairy cows drink, if impure, will spread its 

 impurity to their milk, and the quantity and quality of the food 

 also make its influence felt upon the quantity and quality of 

 the milk. 



As 88 per cent, of milk consists of water, a good Shorthorn 

 dairy cow will secrete in her milk 35 pounds of water per diem. 

 There is, therefore, a great demand for water in the economy 

 of the cow yielding milk, and remembering the influence of, 

 food on this secretion, it is easy to comprehend why succulent 

 food should increase the flow. The well-known effects of 

 brewers' grain must also be attributed in part to the fact that 

 the 75 per cent, of water which they contain is somewhat simi- 



