Though found in the tissues in minute quantity, manganese is not essential to life, and does not form an integral part of any protein molecule. Bertrand and Megreccann claim that manganese acts as a catalytic agent for iron, an almost infinitesimal amount causing an increased absorption and utilization by the tissues. In anemia it is sometimes given with iron, e. g., in the form of a peptonate or albuminate.

Manganese dioxide, dose, 2 grains (0.013 gm.), and potassium permanganate, dose, 1 grain (0.06 gm.), are official and have a reputation as emmenagogues. Potassium permanganate, through its oxidizing powers, is locally antidotal to morphine, and in 1:10,000 to 1:1000 aqueous solution has considerable value as an antiseptic and deodorizer. In India it has been found useful locally in snake-bite, and it is recommended by von Adelung in ivy-poisoning. Calcium permanganate, a less irritating compound, is used by Rogers for colon irrigations in amebic dysentery. He uses 15 grains (1 gm.) to a pint (480 c.c.).

Chronic poisoning occurs in workers in zinc mines, manganese grinding mills, and among those making potassium permanganate. Great muscular weakness, a coarse intention tremor, muffled speech, and depressed cerebration are the most striking features. In some cases there is pronounced hysteria. The treatment consists of hydrotherapy, electricity, and physical exercises.