4 Composition and Nutritive Value of Straw. 



speaking few organic examinations of straw have been made. 

 With but few exceptions the published organic analyses are not 

 sufficiently explicit for practical purposes, and hence it is not 

 surprising that men who base their opinion on such imperfect 

 or partial analyses should make exaggerated statements respect- 

 ing the high feeding value of straw. In most of these analyses 

 we find the components grouped together in the following 

 manner : 



1. Water. 



2. Nitrogenised substances. 



3. Non-nitrogenised substances. 



4. Mineral substances (ash). 



1. The amount of water in well -harvested straw when the 

 corn is stacked varies from 25 to 36 per cent. After stacking a 

 good deal of water evaporates, and the amount soon sinks to 

 16 or 18 per cent. Straw being a very hygroscopic substance is 

 much damper in autumn and spring than in summer, or in a 

 wet than in a dry month. I have found as little as 8 per cent, 

 and as much as 19 per cent, of water in straw of the same kind 

 taken at different times from the outside of the same stack. 

 Making every allowance for variations depending upon the state 

 of the atmosphere and on the age of the straw, 16 per cent, may 

 be taken as fairly representing its average proportion of water. 



2. The group of nitrogenised substances includes albumen 

 and vegetable casein two compounds soluble in water and 

 vegetable fibrin and other albuminous compounds, which are in- 

 soluble in water, but readily rendered soluble by weak alkaline 

 solutions. All the nitrogenised compounds contain about 16 per 

 cent, of nitrogen, and, besides carbon, oxygen, and hydrogen, 

 small quantities of sulphur and phosphorus. Thev^ resemble 

 each other so closely in composition and properties as to be 

 scarcely distinguishable. As the type of this interesting class of 

 compounds we may regard vegetable albumen a substance 

 analogous if not identical in properties and composition with the 

 white of eggs. On account of the close resemblance of vegetable 

 casein, fibrin, &c., to albumen, the compounds of this group 

 are often called albuminous matter. By a simple chemical pro- 

 cess all furnish a substance which its discoverer, Professor Mulder, 

 named protein. According to this illustrious chemist, albu- 

 minous substances are combinations of protein with small quan- 

 tities of sulphur and phosphorus, and hence they are termed 

 frequently protein compounds. Not only are these vegetable 

 substances nearly identical in composition and properties, but 

 they likewise resemble so intimately animal casein, albumen, 

 and fibrin, or those materials of which the flesh and blood of 

 animals principally consist, that they have been called with 



