Thus we see that food has another function besides that of forming animal matter, namely to supply heat. When the food does not contain a sufficient quantity of starch, sugar, etc., to answer the demands of the system the animal's own fat is carried to the lungs, and there used in the production of heat. This important fact will be referred to again.
FOOTNOTES:
[G] By proximate principle, we mean that combination of vegetable elements which is known as a vegetable product, such as wood, etc.
[H] Muscle is lean meat, it gives to animals their strength and ability to perform labor.
[I] This, of course, supposes that the soil is fertile in other respects.
CHAPTER VII.
LOCATION OF THE PROXIMATES AND VARIATIONS IN THE ASHES OF PLANTS.
Of what proximate are plants chiefly composed?
What is the principal constituent of the potato root?
Of the carrot and turnip?