Preparation

This preparation, first made known as a remedy by Mr. William Kerr, of Scotland, in 1832, has been adopted as officinal in the U. S. and Br. Pharmacopoeias. As made by the process of Mr. Kerr, and according to former officinal directions, by simply dissolving iron wire in nitric acid, with the addition of water to give it a certain strength, it was a solution of the mixed nitrates of the protoxide and sesquioxide of iron, and consequently, on exposure to the air, was apt to become turbid by the further oxidation of the protoxide, and the deposition of a subnitrate of the sesquioxide. Mr. Kerr obviated this effect by adding to the solution a little muriatic acid, which dissolves the sesquioxide as fast as formed. By the present formula of the U. S. Pharmacopoeia, which was framed according to suggestions of Prof. Procter, it is believed that the difficulty at first experienced has been obviated, and a solution obtained of the nitrate of the sesquioxide of iron without any protoxide whatever. (See U. S. Dispensatory, 12th ed., p. 1199).

Properties

The solution, as made by the former process, is of a dark colour, and apt to become turbid; by the improved method, is of a pale-amber colour and permanent. The taste is ferruginous, acid, and very astringent, but not corrosive. All substances are incompatible with it which form insoluble compounds with sesquioxide of iron, and soluble compounds with nitric acid; consequently, ferrocyanide of potassium, phosphate of soda, and the alkaline sulphurets; and with all the vegetable astringents it affords copious black precipitates. The alkalies and alkaline earths precipitate the base.

Medical Use

This preparation operates like the soluble salts of iron in general; that is, locally as an astringent, and either a moderate excitant or irritant, according to the dose, or the strength of the solution employed; and upon the system at large, as a tonic and reconstructive agent; though, in these latter respects, much inferior to the protosalts of iron, or the metal itself in impalpable powder. It would no doubt prove useful in debilitated states of the stomach and bowels, in the absence of inflammation; and will occasionally cure diarrhoeas connected with this condition of the alimentary canal. It was as a remedy in diarrhoea that it was introduced into practice; and much testimony has been adduced in its favour. From the trials I have made with it, I do not consider it superior to the other soluble chalybeates for this purpose, especially the sulphate, when care is taken not to administer that remedy in an overdose. From the experiments of Quevenne, it may be inferred that it must be decomposed and undergo precipitation in the stomach, like the other soluble salts of iron, and consequently does not reach the seat of its operation in the small intestines, in the state of nitrate. The very blackening of the stools is alone evidence of decomposition. The dose is from five to thirty drops, from two to four times a day, which may be gradually increased, if necessary, while borne without inconvenience. In an over dose it will irritate and inflame, if not corrode the stomach and bowels. It should be borne in mind that the British preparation is about twice as strong as that of our Pharmacopoeia; and should not be given in more than half the dose.

The solution has been locally used as an injection in leucorrhoea, diluted so as to produce only a slight smarting sensation; but it is probably inferior, in this and other mucous discharges, to the sulphate of iron, as being less astringent.