SOME OE THE ANIMIAES EED AND SLAUGHTEEED AS HUMAN EOOD. 549 
3. Relation of the Fat stored up in the Increase, to the ready-formed Fat, and other 
Constituents, consumed in the Food ; &c. 
The amount oifat in the food of the ditferent lots of Sheep which have served in the 
foregoing illustrations, was not determined, so that the relation of that estimated as 
stored up in increase, to that ready-formed in the food, cannot be shown in their case. 
In the majority of the experiments with the Pigs, the amount of ready-formed fat in 
the food was determined. The amount stored up in the increase, has also been legiti- 
mately deduced from experimental evidence. The results show, as already noticed, that 
there were on the average, between 400 and 600 parts of Fat stored up in the increase, 
for 100 of Fatty matter consumed in food. In the case of the analysed fat Pig, there 
were 405 parts of Fat stored up for 100 consumed. The result in this instance was 
obtained in as direct a manner as the nature of the question will admit of, and it may 
be taken as representing the truth very closely. The average of the other experiments 
shows 472 parts of Fat in increase, for 100 ready-formed in food. Nor is there much 
reason to doubt the general accuracy of this latter indication. Upon the whole, it is 
obnous, that a large proportion of the Fat of the fattening animal {^produced from other 
constituents than Fat in the food. Attention has elsewhere been called to the evidence 
of this, afforded in the instance of the analysed fat Pig *. It was shown that in its case 
rather more than three-fourths of the Fat of the increase gained on the fattening food, 
must have been formed in the body from other constituents ; and it was pointed out, 
that if the produced Fat were due to the Starch of the food, it would require about 2^ 
parts of that substance, to yield 1 part of Fat. On this supposition, it is obvious, that a 
much larger proportion of the non-nitrogenous constituents of the food, will directly 
contribute to the non-nitrogenous substance of the increase (fat), than is represented by 
the total amount of the Fat itself, stored up. It is equally obvious, that the proportion 
of the total dry substance of the food consumed, which has (if we may draw such a 
distinction) directly contributed to the dry matter of increase, including the produced 
Fat, will be much greater than that indicated by the total amount of the dry substance 
of the increase. The proportion which is expired, perspired, or voided, without having, 
in the sense implied, directly contributed to increase, will, of course, in a complementary 
degree, be less than the total amount represented as expired, perspired, or voided. 
To illustrate, numerically, the points above alluded to, there are shown, in Table XVI., 
for the analysed fat Pig, and for most of the sets of Pigs before under consideration — 
the amount of Fat stored up in the increase for 100 of dry matter of food consumed; 
the proportion of Fat already formed in the food ; the amount that must have been pro- 
duced from other compounds ; the amount of Starch that would be required if the pro- 
duced Fat were formed from it; the proportion of the total dry matter consumed, which 
would be thus required directly to contribute to the fixed increase ; and lastly, the pro- 
portion that would be expired, perspired, or voided, without thus directly contributing 
to the fixed increase. 
* Keport of the British Association for the Advancement of Science for 1852. 
MDCCCLIX. 4 Q 
