The metals whose salts are found in the body are sodium, potassium, calcium, and magnesium. These metals in their elementary state are seldom seen outside a chemist's laboratory, but we can judge of their importance when we remember that the digestive juices contain these metals. The teeth and all bony substances are formed from these compounds, and the ability of all body-fluids to carry food material in solution depends upon a definite per cent of these metal salts. The study of minerals, or of mineral salts contained in food, together with their uses in the body, forms an important subdivision of food chemistry.
Iron—Iron is mentioned separately from other metals because it not only yields salts that occur in small quantities in the body, but because, like sulphur, it enters into the complex nitrogenous portions of the body to form part of the living substance itself.
Iron in patent medicines
This organic iron, as it is sometimes called, occurs chiefly in the red blood-corpuscles. The patent medicines which are exploited for the iron they contain, are frauds so far as nourishing the body is concerned. The popular deception is caused by the general belief that all compounds containing the same elements are alike in their uses. One might as well swallow iron filings as to endeavor to build red blood corpuscles out of the mineral solution of iron.
[LESSON III]
ORGANIC CHEMISTRY