Carbon combined with oxygen forms carbon dioxid.
Oxygen, nitrogen, and carbon dioxid largely form the air.
Oxygen and hydrogen form water.
Calcium, iron, magnesium, sodium, and potassium are used in the formation of the various tissues and secretions of the body.
The substances contained in living organisms are the same as those in inorganic matter, only in different complexities as appropriated to the needs of each organism.
The difference between living and non-living matter is in the relative proportion and arrangement of the same elements.
Before it is fit to supply the needs of the body, the raw material must undergo a chemical change.
It has been demonstrated by scientific investigation that no unorganized elements, such as pure nitrogen, pure iron or magnesium, are assimilated by the system and converted into its various structures.
While the body needs carbon, it cannot use coal; it needs nitrogen, yet it cannot appropriate it to rebuilding bone and muscle, until, by chemical action with other elements, it has been converted into complex substances called proteins.
The muscles, ligaments, and labor-performing structures contain the largest amount of nitrogen.