On The Necessity for Proper Foodstuffs. 315 
And it is to supply the daily waste, in order that the 
body may do work that food is taken. The oxgen and 
most of the water have as I have stated above been fully 
studied previously. The hydrogen plays but so small a 
part in the economy that it does not require any special 
study here, the body always finding enough of this 
element in almost any combination of foods forming a 
diet. The carbon, nitrogen and salts are found combined 
in various proportions in the animal and vegetable world, 
from which fact another classification of foods is fre- 
quently made. The nitrogenous bodies for the most 
part belong to the animal kingdom and are generally 
albumens, the carbons, called mostly carbo-hydrates, to 
the vegetable kingdom, in the forms of starches and 
sugars, while salts are found combined both with the 
albumen and carbo-hydrates. The few other salts 
used came directly from the mineral world. The fats 
which form another important element in a good dietary 
can be obtained from both animals and vegetables, but 
in the human economy it has been found that a deficiency 
of fat in a diet can be compensated for by the use of more 
carbo-hydrates, which are in such cases converted into 
fats. 
It is important to remember that although this classifi- 
cation of foods is correct generally, there is nothing 
absolute in it for we find that nitrogenous bodies exist 
in wheat (10 parts nitrogenous to 36 parts non-nitro- 
genous), in rice (10 parts nitrogenous to 123 parts non- 
nitrogenous), in plantains 375 cent nitrogenous, 96*25 
per cent non-nitrogenous), and non-nitrogenous bodies 
in beef, (10 parts nitrogenous to 17 non-nitrogenous), in 
milk (10 nitrogenous to 30 non-nitrogenous), and so on 
