262 PROFESSOR LIEBIG ON THE AZOTIZED 
Now we find that the flesh of graminivorous, and especially 
of domestic animals, which eat a great deal of food without ni- 
trogen, is very fat; and that this fat may be increased, by in- 
creasing the supply of this kind of food. The flesh of carnivo- 
rous animals is without fat, and sinewy; all the food which they 
eat contains nitrogen, except the fat of the animals they devour. 
It is evident that starch, sugar, and gum, are incapable of 
supplying that loss which is continually occasioned in animals 
by the vital powers; they are incapable of forming muscular 
fibre, cerebral matter, the membranes, or the bones and sinews, 
because their only ingredients are carbon, and the elements of 
water ; they contain neither nitrogen, phosphorus, lime, sulphur, 
nor iron. Children fed on such food become very fat ; but nei- 
ther their muscles nor their bones can increase, and they them- 
selves therefore cannot become stronger. Physicians are well 
acquainted with the fact, that children who are not supplied with 
a sufficient quantity of lime in their food, eat that which they 
collect from the walls of houses, with the same appetite that 
they have for their meals. 
When we compare the chemical composition of such bodies 
as sugar, gum, and amylin, with that of fat, we find that they 
contain the same quantity of carbon and hydrogen, and that the 
only difference is in the quantity of oxygen, which is smaller in 
the fat bodies. 
According to the analyses of Chevreul, which are the most 
accurate and most to be trusted, the following is the composition 
of the fat of swine, of sheep, and of man :— 
Swine. Sheep. Man. 
Carbon . . 79°098 78:996 79:000 
Hydrogen . 11°146 11:700 117416 
ZV Gen Sea goo 9°304 9°584 
Amylin. aa ob eae Gum. 
Carbon . . 44°91 40°45 42°58 
Hydroven |. ~G-11 6°61 6°37 
Oxygen . . 48°98 52°64 51°05 
In amylin the proportion of carbon to hydrogen is the same 
as in the fat of swine, namely 44°91 : 6°11, or as 79 to 11. 
Sugar of grapes, sugar of milk, cane sugar and gum, are di- 
stinguished from amylin by containing a certain quantity of 
carbon and hydrogen, in the same proportion as water, over and 
