440 On the Composition of Oxen, Sheep, and Pic/s, 
It sliould here be' particularly observed, that taking into con- 
sideration the cost of many of the foods which are hig-h, com- 
pared with that of those which are low in their percentage of 
nitrogenous substance, and also the higher value of the manure 
from those which are rich in nitrogen, it is almost invariably the 
most profitable for the farmer to employ stock-foods containing a 
larger proportion of nitrogenous constituents — even up to the end 
of the feeding process — than is essential for the maximum rate 
of increase. 
From a view of the whole of the evidence bearing upon this 
branch of the subject, it maybe concluded, that Avhen stock-foods 
contain a certain amount of nitrogenous substance below ivhich 
few of our current fattening food-stuffs are found to go, it is their 
supply of available 72o?i-nitrogenous, rather than that of their nitro- 
genous constituents, which rules both the amount of the food con- 
sinned, and the increase in live-weight produced. 
When it is considered how large is the share of influence which 
the demands of the respiratory process must have upon the amount 
of food consumed, it can hardly excite surprise that, at least 
consumption, should be chiefly regulated by the supply of com- 
pounds rich in carbon and hydrogen, rather than nitrogen. 
That the amount of increase should also bear a closer relation- 
ship to the amount of the ?io?i-nitrogenous than to that of the 
nitrogenous constituents of food, will doubtless appear to be incon- 
sistent with the generally-adopted notion of the highly nitrogenous 
character of animal bodies, and especially with the also frequently 
implied assumption that in the current food-stuffs the proportion 
of nitrogenous substance is likely to be often insufficient to supply 
the amount required for the production, or restoration, of the nitro- 
genous compounds of the animal organism. 
The questions here arise — what is the composition of the 
animals the farmer feeds? — what the composition of their in- 
crease whilst fattening ? — and what the relation of this to that of 
the food consumed ? ; 
II. On the Proportion, and Relative Development, of 
THE DIFFERENT OrGANS AND PaRTS, OF FATTENING OXEN, 
Sheep, and Pigs. 
Before discussing the chemical composition of the animal bodies, 
and of their increase, it will be well to consider the proportion 
■which the various organs (or other more arbitrarily separated 
parts) bear to the entire body, in the different descriptions of 
animal, and also the proportion, and tendency of development, 
according to the condition of growth or fatness. In fact, it is 
the judgment of the character of the slaughtered animals in these 
