This is prepared by passing hydrogen over sesquioxide of iron heated to redness. The hydrogen abstracts oxygen from the sesquioxide, and escapes as watery vapour, leaving the iron in a metallic state. This is powdered, and kept in well-stopped bottles.

Properties

It is a dark iron-gray powder, without smell or taste. A little of it, struck with a smooth hammer upon an anvil, forms a scale having the metallic lustre. Thrown into a dilute acid, it produces effervescence, with the escape of hydrogen. It rapidly oxidizes on exposure to the air, from which it should be as much as possible excluded. If quite black, and but feebly effervescing with dilute acids, it may be looked on as not having been fully reduced, and consequently imperfect.

Effects on the System

Powdered iron produces all the characteristic effects of the metal on the system, but has little action on the stomach locally. Nevertheless, in very large doses, it sometimes disturbs the bowels, and has been known to cause vomiting. When there is any acid in the stomach, it is rapidly dissolved, being probably first oxidized at the expense of the water, and then combining with the acid. From the experiments of Quevenne, it appears to yield a larger proportion of iron to the gastric liquor than any other preparation of the metal, given in the same quantity.

Therapeutic Application

This particular form of powdered iron was first introduced to the notice of the profession by M.M. Quevenne and Miquelard, of Paris, and has now come into general use. Its want of taste, the smallness of its dose, and the mildness of its action are valuable qualities; but the facility of its solution in the gastric liquids, and of its absorption, constitutes its great recommendation. It may be employed with advantage in all cases, in which the object is to introduce iron into the system through the circulation. Perhaps no chalybeate is superior to it in tin's respect. It has been specially employed in anaemia, and acts with great efficiency in this affection, in all cases which are amenable to the influence of iron. An objection has been urged against all the forms of metallic iron, that they occasion unpleasant flatulence, by the hydrogen liberated in the stomach. But, in reference to this particular preparation at least, the objection is rather theoretical than practical; the dose being too small to produce any great effect of the kind. Three grains of it could evolve only about one-tenth of a grain of hydrogen. It is not adapted to those cases, in which the indication is to act exclusively or specially on the mucous membrane of the stomach and bowels by direct contact.

Administration

The dose is from three to five grains twice or three times a day, which may be increased if necessary. From fifteen to thirty grains of the powder prove irritant, disturbing the bowels, and more or less incommoding the stomach, though very rarely vomiting. It may be given mixed with syrup, or in pill.