214 0}i the Theoretical and Practical Value of 
it is more liberally supplied with food which is, comparatively 
speaking, poor in nitrogen and rich in readily digestible starchy 
or sugary compounds? 
Will the increase in the live-weight be determined by the 
excess of the nitrogenous, or by that of the non-nitrogenous con- 
stituents (the carbon-hydrates) of food ? These questions can 
only be answered satisfactorily by experience ; and numerous 
carefully conducted feeding experiments, as well as the experience 
of fatteners of stock on a large scale, have clearly decided the 
fact, that the comparative feeding value of most of our stock- 
foods depends more upon the proportion of the digestible non- 
nitrogenous substances (or carbon-hydrates) which they con- 
tain, than upon their richness in albuminous or nitrogenous 
compounds. 
A few examples will show that it is not the proportion of 
nitrogenous matter in articles of food of the same or similar 
kind which regulates their comparative nutritive value. Tail- 
wheat is richer in nitrogen than fine plump wheat, yet nobody I 
suppose would use tail-wheat for fattening purposes if he could 
get wheat rich in starch, producing much flour in the mill, at 
the same price as inferior samples. I well remember that, a good 
many years ago, the late Mr. Henry Stephens, author of the 
' Book of the Farm,' sent me, for analysis, two samples of wheat, 
and requested me to determine their comparative value. My 
report was made in accordance with the then all but general 
theory, that the proportion of nitrogen in different samples of the 
same kind of food regulated their comparative value ; and 
having found a good deal more nitrogen in one than in the other 
of the two samples of wheat, to my surprise I was subsequently 
informed by Mr. Henry Stephens that the sample which I pro- 
nounced to be a good deal the more nutritious, in point of fact 
was tail-wheat, and the other a much superior and more highly 
priced wheat. 
Again, grass from irrigated meadows, or Italian rye-grass 
grown with sewage, invariably contains more nitrogen than grass 
from dry pastures, or rye-grass grown without manure ; but no 
good farmer prefers the grass from irrigated meadows, or rye- 
grass forced by town sewage, to the better matured and less 
nitrogenous produce of non-irrigated land. 
The same remarks apply with equal force to the comparative 
feeding-value of mangolds, swedes, turnips, and other root- 
crops. It is not the proportion of nitrogenous matter in roots, 
but their percentage of sugar and other equally digestible non- 
nitrogenous constituents which regulates their comparative 
feeding-value. Thus the percentage of nitrogen in monster roots, 
weighing over 15 lbs., is larger than that in roots of the same 
