82 THE CHEMISTRY OF THE FARM. 



matter, had 7G per cent, of this in a digestible form. The 

 precise nature of the digested and undigested nitrogenous 

 matter has not yet been ascertained ; amides being sokible 

 bodies have probably been classed in these experiments 

 as digestible albumin. 



Of the fibre in hay and straw about 40 to GO per cent. 

 is generally digested by ruminant animals. The fibre of 

 leguminous hay and straw (clover and lucerne hay, and 

 bean straw) is considerably less digestible than the fibre 

 of similar graminaceous foods (grass hay, oat and wheat 

 straw). It has been shown that both in the case of 

 the soluble carbo-hydrates, and of the fibre, the portion 

 digested has always the general formula of starch oi 

 oellulose, CgHioOr,, while the portion left undigested is 

 much richer in carbon. It appears, therefore, that while 

 oellulose is a digestible substance, the lignose which is 

 deposited in the tissues as the plant increases in age, and 

 which contains a larger proportion of carbon, is indigestible 

 Chemical analysis shows that the fibre of leguminous hay 

 and straw is richer in carbon, and consequently in lignose, 

 than the fibre of grass hay, or corn straw. 



We must now glance at the circumstances which 

 influence the proportion of food digested. The individual 

 character of the animal undoubtedly affects the proportion 

 digested. Of two animals supplied with the same food, 

 one will often persistently digest a larger proportion than 

 the other. In young animals the digestive power is appa- 

 rently very similar to that of animals of full age. Sheep 

 from six to fourteen months old showed no distinct change 

 in digestive capacity. 



Differences in the quantity of the daily ration of hay do 

 not sensibly affect the proportion digested ; an animal will 



