474 On the Composition of Oxen, Sheep, and Pigs, 
For 100 of ?ioM-nitrogenous constituents of food, the pigs seem 
to have stored up 20 or more of fat, whilst the sheep yielded only 
half that proportion. 
For 100 of nitrof/enons compounds consumed by the pigs there 
was, according to the estimates, on the average about li time as 
much stored up in the increase as in the case of sheep. Not 
that the increase of the fattening pig contains a larger proportion 
of nitrogen than that of the sheep — indeed it is more likely to 
contain less ; but a larger proportion of the total dry substance 
of the food of the pig is digestible and available for increase, 
and accordingly, as already noticed, a given amount of it yields 
a much larger proportion of total dry increase ; and with this, a 
larger actual amount of nitrogenous increase. 
The average of the estimates for the pigs shows 7 "34 per cent, 
of the consumed nitrogen to be stored up in the increase, against 
7"76 per cent, in the case of the analysed fat pig. The greater 
the proportion of pulse, or other highly nitrogenous matters in 
the fattening food, the smaller will be the proportion of the whole 
consumed nitrogen, that will be stored up in the increase. On 
the other hand, the larger the proportion of cereal grain with its 
comparatively low percentage of nitrogen, the larger will be the 
proportion of the whole nitrogen consumed that will be carried 
off in the increase. The evidence at command leads to the con- 
clusion, that there will be almost uniformly less than 10 per 
cent., and sometimes as little as 6 per cent., of the nitrogen of 
the food of the fattening pig carried off in its increase. 
It has already been pointed out how small, in all probability, 
is the percentage of mineral matter in the increase of the rapidly- 
fattening pig. Reasons were given, however, for supposing that 
our estimates indicated a lower amount than really was the case. 
There is little use, therefore, in examining at all closely results 
that are based upon admittedly doubtful estimates. Moreover, as 
the mineral matter in the food varies very much in its propor- 
tion to those constituents which chiefly rule the amount and 
the character of the increase, the proportion of the mineral matter; 
consumed by the fattening pig (as well as by other animals) 
which will be stored up in the increase, will be much more 
variable than that of the other constituents. It may be safely 
stated, however, that in the case of fattening pigs, the proportion 
of the consumed mineral matter which will not be reclaimed in 
the manure is almost immaterial. The amount that will be lost 
to the manure in the entire bodies of the animals sold is a matter 
of easy calculation from the data recorded in Table XII. 
For every 100 parts of ready-formed fatty matter in the food, 
there were probably, on the average of the experiments with 
pigs, 400 to 500 parts of fat stored up in the increase of the 
