404 CHEMISTEY. 



cheesy matter or casein being the nitrogenous part, and 

 the oily matter or butter the non-nitrogenous part. And 

 the proportions of the two, being as one of the former to 

 four of the latter, furnish a clear indication of what they 

 should be in food generally, making allowances, of course, 

 for varying circumstances. Milk must contain, besides the 

 casein and the oily matter, all the other materials required 

 in both the solids and fluids of the body, else there would 

 be some defect in the nutrition of an animal that lives en- 

 tirely upon milk. We have therefore in this liquid iron 

 for the blood, salt for this and various other fluids in the 

 body, phosphate and carbonate of lime for the bones, etc. 

 The milk, though of a white color, contains in fact all the 

 elements that are present in the red blood of the animal, 

 and in the same proportions, with the exception of that 

 portion of the oxygen which is added to the blood in the 

 lungs. A great error is often committed in confining a 

 child too exclusively to starchy articles of food, such as 

 arrow-root, thus depriving it not only of the albuminous 

 substances, but also of the iron, the phosphate of lime, etc., 

 which are all contained in the complex food furnished it 

 by nature. 



573. Proportions of Heat-Food and Building-Food in Dif- 

 ferent Articles. In the following articles to every 10 parts 

 of nitrogenous substance there are the parts named of non- 

 nitrogenous substance: Cow's milk, 30; pease, 23; beef, 

 17; veal, 1; eggs, 15; wheat flour, 46; oatmeal, 50; rye 

 flour, 57; potatoes, 86; rice, 123; buckwheat flour, 130. 

 There are some variations according to circumstances, but 

 these are the average proportions. The percentage of 

 nitrogenous and non-nitrogenous substance, in three forms 

 of food used largely in three different quarters of the world, 

 may be thus stated : 



