SOSIE OE THE ANIMALS EED AND SLAUGHTBEED AS HUMAN EOOD. 513 
expressed parts, is now obtained by ether determinations made on proportionally mixed 
samples of all the parts of the animal, Carcass and Offal together, the wool only excepted; 
the fat in the wool itself being extracted separately, and its amount taken into the cal- 
culation. A glance at the two columns (6 and 6) will show that there is never half, and 
in only one or two cases, one-fourth of 1 per cent, of variation between the results 
obtained by the two different methods. 
The striking fact appears, that, of the whole body (fasted live-weight), 45 f per cent, of 
the veiy fat Sheep, and 42 per cent, of the moderately fat Pig, were dry fatty matter. 
Of the moderately fat Sheep 35^ per cent., of the moderately fat Bullock 30 per cent., 
and of the fat Lamb 28^ per cent, were dry fat. The half-fat old Sheep contained 23i 
and the half-fat Bullock 18| per cent, of fat. The store Sheep even contained 18f, and 
the store Pig 23-^ per cent. Of the Calf, on the other hand, the entire body, though 
professedly fat, yielded only 14f per cent, of its weight of dry fatty substance. 
It may, perhaps, from these data be concluded, that fattened Oxen of good quality, 
wih, on the average, consist of fat, to the amount of nearly one-third of their whole 
weight ; moderately fattened Sheep, to rather more ; and moderately fattened Pigs, to 
more still ; whilst, probably, fat Bacon-Pigs will frequently contain fat to the amount 
of one-half of their whole live-weight. 
Section V.— THE NITEOGEN— IN CEETAIN SEPAEATED PAETS, AND IN THE ENTIEE 
BODIES, OF 10 ANIMALS ANALYSED. 
It has been shown, how large is the proportion of the whole body, of some of the 
animals of most importance as human food, which fatty matter. It has been further 
seen, that the proportion of fat in the collective Carcass parts, that is those which are 
the more exclusively appropriated to food purposes, is still greater than in the whole 
body. The next point of interest is as to the proportion, in the whole body or certain 
collective parts, of nitrogen and the thence calculated amount of protein or other 
nitrogenous compounds, a class of constituents, the comparative predominance of which 
IS generally supposed so prominently to characterize our animal food. 
The nitrogen was determined upon mixed samples of the crude dry matters remaining 
after the removal of fat by melting and expression, as follow : — 
{a) Of all soft parts of the carcass : 
{h) Of carcass bones : 
{c) Of offal, soft parts and bones together (excluding hair or wool) ; 
{d) Of all parts, carcass and offal together (excluding hair or wool). 
It was also determined upon the hair or wool separately. The exceptions to the 
above arrangement were, that, in the cases of the Pigs, the mixed sample of Carcass 
included both soft parts and bones, that of the Offal was without bones, and a separate 
mixture was made of the head and feet, soft parts and bones together. 
The actual experimental determinations of nitrogen, in the expressed nitrogenous 
residues, mixed as above described, are given in Table XIV. in the Appendix. The 
calculated mean results are given in a detailed form m Table V., and in a summary one 
in Table VI., which now follow. 
