DR. PROUT ON ANIMAL CHEMISTRY. 
495 
ing of the other two ? In reply to this question, it may be observed 
in the first place, that, in almost every instance, what animals ac¬ 
tually do for the most part , is to be considered as the rule ; while 
what they can do on an emergency is generally an exception. It 
is one of the grand characteristics of organized beings, and by 
which they are more than by any thing else distinguished from 
common crystallized bodies, that they possess the power of vary¬ 
ing their habits, and accommodating themselves to circumstances 
within certain limits, and for a certain time. That many animals, 
therefore, can for a time live on one of these classes of aliments 
alone, cannot be doubted; but that they can do so for an unlimited 
time is exceedingly unlikely, judging from what we actually know 
by observation to be the case, as well as from experiments made 
by different physiologists on this particular subject, both of which 
are decidedly against the supposition, and, indeed, lead to con¬ 
clusions directly opposite, viz., that a mixture of two at least, if 
not all three of the classes, are necessary to constitute a perfect 
alimentary compound. 
It is a curious circumstance that milk , the only article abso¬ 
lutely prepared and intended by nature as an aliment, is a com¬ 
pound of all the three classes ; and almost all the gramineous and 
herbaceous matters employed as food by the lower animals, con¬ 
tain at least two, if not all the three. The same is true of animal 
aliments, which consist at least of albumen and oil. In short, it 
is perhaps impossible to name a substance employed by the more 
perfect animals as food, that does not essentially constitute a na¬ 
tural compound of at least two, if not all three of these great prin¬ 
ciples of alimentary principles. But it is in the artificial food of 
man that we see this great principle of mixture most strongly ex¬ 
emplified. He, dissatisfied with the productions spontaneously 
furnished by nature, culls from every source; and by the power 
of his reason, or rather of his instinct, forms, in every possible 
manner, and under every disguise, the same great alimentary 
compound. This, after all his cooking and his art, how much 
soever he may be disinclined to believe it, is the sole object of his 
labour; and the more nearly his results approach to this, the more 
nearly they approach perfection. Even in the utmost refinements 
of his luxury, and in his choicest delicacies, the same great prin¬ 
ciple is attended to; and his sugar and flour, his eggs and butter, 
m all their various forms and combinations, are nothing more nor 
less than disguised imitations of the great alimentary prototype, 
milky as furnished to him by nature*. 
We come now to take a summary view of the important process 
* See Blumenbach’s Physiology, translated by Dr. Elliotson, page 311 
fourth edition. 
