216 
The JppHcalions of Physiology 
plants. Hence these must contain substances adapted for the 
sustenance of the animal frame. 
All vejijetablc food has been found to contain a peculiar sub- 
stance, which, though it differs in appearance and in form, ac- 
cording to the source from whence it is obtained, is in reality the 
same body. It has received the name of gluten or albumen, and 
is precisely identical, in chemical composition, with the albumen 
obtained from the white of an egg. This substance is invariably 
present in all nutritious food. Chemists were surprised to discover 
that this body never varies in composition ; that it is exactly the 
same in corn, beans, or from whatever plant it is extracted. But 
their surprise was much increased when they remarked that it is 
quite identical with the flesh and blood of animals. It consists, 
like the latter, of carbon, hydrogen, nitrogen, and oxygen, and in 
the very same proportion in 100 parts. By identity in composi- 
tion is not meant a mere similarity, but an absolute identity ; so 
much so, that if you were to place in a chemist's hand some 
gluten obtained from wheat flour, some dry albumen procured 
from the white of an egg, a fragment of the flesh of an ox or of a 
man, or some of their dried blood, and request him to examine 
their difference, he would tell you, strange as it may appear, that 
they are precisely the same, and that with all the refinements of 
his science he was unable to detect any essential diffei'encc be- 
tween them. There is much difference, indeed, in external 
appearance and in structure, but in their ultimate composition 
there is none. To render this more obvious I subjoin the com- 
position of these various substances, as obtained by different che- 
mists, who executed their analyses without any knowledge of the 
results obtained by the others : — 
Glulcn 
Casein 
Albumen 
from Flour. 
from Pease. 
from Ei^ys. 
Ox Blood. 
Ox Flesh. 
lioussiogauU. 
Scherer. 
Jones. 
Playfair. 
Playfair. 
Carbon • 
. .54-2 
64-138 
55-000 
54-35 
51-12 
Hydrogen 
. 7-5 
7-156 
7-073 
7-50 
7-89 
Nitrogen . 
. 13-9 
15-672 
15-920 
15-76 
15-67 
Oxygen . 
. 24-4 
23-034 
22-007 
22-39 
22-32 
100-0 
100-0 
100-00 
100-00 
100-00 
These analyses do not differ from each other more than the 
analyses of the same substance usually do. Thus we are led to 
the startling conclusion, that plants contain Avithin them the flesh 
of animals ready formed, and that the only duty of animals sub- 
sisting upon them is to give this flesh a place and form in 
their organism. When an animal subsists upon flesh, we find no 
difficulty in explaining its nutrition ; for the flesh being of the 
same composition as its own body, the animal, in a chemical point 
of view, may be said to be eating itself; nor, with a knowledge 
