Iron (Fe = 55.5) is found widely distributed in nature, but its principal native form is that of the oxide. It is an important constituent of the blood and other animal tissues, and of many vegetable substances.

Pharmacodynamics.

Central Nervous System. - No direct action known.

Muscular System. - No direct action known.

Respiration. - No direct action known.

Heart. - No direct action known.

Blood-pressure. - No direct action known.

Alimentary Tract. - Mildly irritant.

Secretory Glands. - No action.

Metabolism. - Iron must exert some profound influence, inasmuch as a deficiency of this element is accompanied by very grave symptoms; but the mechanics of its action is quite unknown, except for the physiology of hematin as an oxygen carrier.

Temperature. - No action.

Absorption. - Iron is slowly absorbed in minute quantities, either in metallic form or in solution. It is taken up by the epithelium of the duodenum, carried thence to the spleen, then to the liver, where it is utilized slowly by the blood.

Excretion takes place through the caecum and colon.

Local Action. - None.

Note. - Because of its deleterious influence on the teeth, Tinctura Ferri Chloridi ought to be proscribed, never prescribed.

Symptoms.

Therapeutic Doses. Astringent metallic taste.

Prolonged Use.

Some dyspepsia. Constipation. Blackening of the teeth. Hyperacidity of the stomach.

Large Doses.

Gastric uneasiness. Nausea and vomiting. Intestinal irritation. Fullness in the head.

Therapeutics.

Iron is a specific in a large proportion of cases of chlorosis.

Of all the official preparations of iron two only need be mentioned, the carbonate and the citrate.

Dosage.

Pilulae Ferri Carbonatis, 1 pill = 0.06 Gm. Ferri Citras, 0.12 to 0.3 Gm.