LIEBIG REVIEWED. 
419 
contain proteine ready formed or not, easily yield it when acted 
on by alkalies. While proteine, however, contains no inorganic 
matter, albumen, fi brine, and caseine, each contains small but 
essential quantities of mineral substances, such as sulphur, phos- 
phorus, potash, soda, common salt, and phosphate of lime. 
Farther, it has been established by the still more recent disco- 
veries of Liebig, that animal and vegetable albumen, animal and 
vegetable fibrine, and animal and vegetable caseine, are respect- 
ively identical in every particular. We may therefore assume 
that there is but one albumen, one fibrine, and one caseine ; and 
that it is convenient to consider them all as compounds of pro- 
teine, with small proportions of inorganic matter. 
According to the theory of Liebig, proteine is produced by 
vegetables alone, and cannot be formed by animals ; although the 
animal organism possesses the power of converting one modifica- 
tion of proteine into another, fibrine into albumen, or vice versa ; 
or both into caseine, &c. 
The following ultimate analyses by some of the most distin- 
guished chemists prove these different positions : — 
Ultimate 
Elements. 
Vegetable 
Fibrine 
byScherer 
Vegetable 
Albumen 
by Bous- 
sengault. 
Vegetable 
Caseine 
byScherer 
Flesh— : 
Beef, by j 
Playfair. 
Albumen 
from the 
Scrum of 
Blood, by 
Scherer. 
Fibrine 
(Animal) 
byScherer 
Animal 
Caseine, 
by 
Scherer, 
from fresh 
Milk. 
Proteine, 
from 
Vegetable 
Albumen 
by Mul- 
der. 
Proteine, 
from Ani- 
mal Albu- 
men, by 
Scherer. 
Carbon 
53.064 
52.7 
54.138 
51.83 
58.850 
53.671 
54.825 
54.99 
55.160 
Hydrogen — 
7.132 
6.9 
7.156 
7.57 
6.983 
6.878 
7.153 
6.87 
7.055 
Nitrogen 
15.359 
18.4 
15.672 
15.01 
15.673 
15.763 
15.628 
15.66 
15.966 
Oxygen . . 
Sulphur... 1 
Phospho- m 
rus, &c.. j 
24.445 
22.0 
23.034 
25.60 
23.494 
23.688 
22.394 
22.48 
21.819 
The nutritive process is seen in its simplest form in carnivorous 
animals, who live on the blood and flesh of the graminivora ; but 
their blood and flesh are, in all their properties, identical with their 
own. With the exception of hoofs, hair, feathers, and the earth 
of bones, every part of the food of carnivorous animals is capable 
of assimilation. “ Thus, in a chemical sense,” says Liebig, “ it 
may be said that a carnivorous animal, in supporting the process, 
consumes itself : that which serves for its nutrition is identical with 
those parts of its organization which are to be renewed.” 
