434 On the Composition of Oxen, Sheep, and Pigs, 
2. The amount of food, or of its several constituents, consumed 
— to produce a given amount of increase in live-tceight. 
3. The proportion, and relative development, of the different 
organs, or j)arfs, of fattening animals ;— their chemical composi- 
tion ; — and the probable composition of their increase during 
the feeding process. 
4. The composition of the solid and liquid excrements — that is, 
the manure — in relation to that of the food consumed. 
5. The loss or expenditure of constituents, by respiration and 
by the cutaneous exhalations — that is, in the mere sustenance oi 
the living meat and manure making machine. 
The discussion of the fourth and fifth branches of the inquiry 
here enumerated, must still be postponed to some future oppor- 
tunity. 
The third branch — namely, that relating to the composition of 
the animals themselves, and of their increase whilst fattening — 
constitutes the special subject of the present paper. 
Before entering upon the consideration of these questions we 
shall give, by way of introduction, a brief summary of the facts and 
conclusions bearing upon the first two, or preliminary points of 
the main inquiry. 
I. On the Amounts of Nitrogenous Compounds, of Non- 
Nitrogenous Compounds, and of Total Dry Substance, 
consumed — IN relation to a given weight of animal 
WITHIN A GIVEN TIME — AND TO PRODUCE A GIVEN AMOUNT 
' OF Increase. 
To acquire the necessary data relating to this branch of the 
subject, some hundreds of animals — oxen, sheep, and pigs — were 
supplied for many weeks or months consecutively, with given 
quantities of food, of known composition ; and the weights of the 
animals themselves were also taken, both at the beginning and at 
the end of the experiments. For full particulars of the results, 
the reader is referred to our detailed Reports, published partly in 
this Journal,* and partly elsewhere.! 
Table I. (p. 436) gives a summary of the results relating to 
Sheep, and Table II. (p. 437) of those relating to Pigs. 
In these Tables the organic substance of the food is only sub- 
divided into the two main classes of — 1st, Total nitrogenous 
substance ; and 2nd, Total non-nitrogenous substance. It is 
obvious that this is a very imperfect classification of the con- 
stituents of food. 
* Journal of the Royal Agricultural Societj' of England, vol. x., part i.; 
vol. xii., part ii.; vol. xiii., part i.; vol. xiv., part ii. ; and vol. xvi., part i. 
t l(ep<irt of the British Association for the Advancement of Science, for 1852„ 
and for 18.'j4. 
