The prepared oxide is obtained by digesting the powdered black oxide in dilute hydrochloric acid for twenty-four hours, then levigating and drying.

MANGANESII SULPHAS - SULPHATE OF MANGANESE, MnSO45H1O, = 241 (NOT OFFICINAL).

Characters

Occurs in colorless, or pale rose-colored, transparent crystals, freely soluble in water.

The double sulphate, the double carbonate, and the double iodide, with iron, are sometimes prescribed; less frequently such compounds as the lactate, phosphate, citrate, and valerianate of manganese (Hannon, Gui-bert). None of them are officinal.

Permanganate of potash (v. p. 267).

Absorption And Elimination

Salts of manganese undergo probably the same changes in the stomach as salts of iron, and are absorbed as albuminates, or as chlorides. The metal, like others, is eliminated mainly by the bile and the intestinal tract. W. Turner found distinct evidence of manganese in the urine of a diabetic patient who had been taking permanganate of potash freely for three weeks, showing that it is, at any rate, partly eliminated by the kidneys (Edinburgh Medical Journal, vol. vi., 1861).

Physiological Action (Internal)

Circulatory System

The presence of manganese as an essential element of the corpuscles has been relied upon as a guide to its action, but it seems to be rather an accidental than a normal constituent of the blood. Wurzer, in 1830, first announced its presence, and Millon, Hannon, and Burin-Dubuisson corroborated this, while Melsens, Bonnewzn, and others, could find no manganese on repeated analyses; Melsens operated on 7 kilogr. of blood from twenty-one different persons. M. Glenard analyzed, in various ways, blood from forty subjects of varying age and sex, and found the metal in one case only. He concluded "that manganese is not an essential element of human blood; it may be found accidentally, but only in minute amount; it does not enter by the lungs or skin, as proved in the case of a miner" (Gazette Medicale de Lyon, 1854). I have not met with any series of analyses for manganese since those quoted. M. Riche, the latest observer, who finds the galvanic test to be exceedingly delicate, has detected minute quantities in the blood of bullocks, etc., but has not tested human blood often enough to speak with authority (Medical Record,

1877). Bartholow, however, considers the question decided affirmatively, and even gives the proportion of manganese to iron in the red corpuscles (human) as 1 to 20. If this be so, we may agree that the administration of manganese would be likely to improve the nutrition and the color of the corpuscles in a direct manner, but so much as this cannot yet be positively stated from physiological research. That manganese has a similar action to that of iron has been often stated, but must be considered problematical (Husemann), and indeed, the increased blood-pressure caused by the latter is not produced by the former drug.

According to Laschkewitz, the organic salts of manganese, in moderate doses, slow the pulse and the heart-action, and cause lowering of blood-pressure, and paralysis of muscles and nerves, which iron certainly does not. After death from manganese poisoning the heart is found dilated, and does not respond to electrical stimulation.