122 



THE CHEMISTRY OF THE FARM 



the latter figures. One thousand parts of the foods 

 used contained the following quantities of fibre, and 

 yielded the following results in the horse : — 



It appears from these results that the work of 

 mastication and digestion (chiefly the latter) involves 

 the combustion of a quantity of nutritive matter, which 

 when deducted from the nutritive matter gained by 

 the digestive process greatly diminishes its amount. 

 We see further that this diminution in the finally 

 available food is nearly connected with the quantity 

 of cellulose which the food contains. In the case of 

 maize nearly 90 per cent, of the digestible matter is 

 finally left for use by the horse ; with potatoes 88 per 

 cent. ; with oats 80 per cent. ; with meadow hay 46'5 



