Chalybeates have thus a most immediate and obvious effect in restoring to the blood this wanting Hæmatosin. As the exact chemical condition of the Iron in Hæmatosin has not been discovered, so also the precise changes which Chalybeate medicines have to undergo before they can supply this deficient material in a fit and proper form, are not known. All the known soluble compounds of Iron, except the Ferrocyanide and Ferridcyanide of Potassium, possess this Restorative power. In most Chalybeates the Iron acts the part of a base; but in some, as the Ammonio-citrate and Potassio-tartrate, it exists in a peculiar condition, and cannot be precipitated from their solutions by Ammonia. The water of Chalybeate springs generally contains a Carbonate of Iron, held in solution by an excess of Carbonic acid. The same salt is contained in the compound Iron mixture and pill of the Pharmacopœia, when these are rightly prepared.
When the Iron has entered the system, it is not necessarily excreted again from it, because it is not unnatural to the blood. To ascertain whether Iron given in small quantities is excreted by the kidneys, I have tested the urine of a patient who had been for some time taking thirty drops of the Tincture of the Sesquichloride twice a day: but I was unable to detect in it any trace of the metal.
But when given in large doses, Iron passes off by the urine and by other secretions. Some portion may be excreted by the mucous membrane of the intestines, and combine in the cavity of the bowel with Sulphuretted Hydrogen. The resulting Sulphuret communicates to the fæces a characteristic black colour. The cause of this colour was ill understood; until pointed out by Berzelius.
When the salts of Iron pass through the glands, they generally prove to be more or less astringent. The Chloride and Sulphate are most so; and they will thus be mentioned again under the head of Astringent medicines. The tincture of the Sesquichloride has obtained the reputation of being diuretic. But this constitutes no exception to the rule of its being astringent; for this diuretic power is owing to a peculiar ether, formed with the spirit by an excess of hydrochloric acid used in the preparation of the tincture.
I believe Iron to be simply and solely a Restorative remedy. By improving the condition of the blood, it appears similar in action to Tonics; but it is not a true Tonic, for neither in debility nor in Ague is it of any service, unless there is at the same time Anæmia. In some cases, even of Anæmia, Iron will not effect a cure. This must be because the appropriative power of the system is so weakened and degenerated, that it is incapable of consigning even this needful substance to its proper destination.
Anæmia is the one disease in which Iron is of use. Purgative medicines form a valuable adjunct to the treatment in most cases. Dr. G. Owen Rees has suggested that they may be of use by removing some of the water of the blood, so that the corpuscles, being then shrivelled by exosmosis of their contents, may be in a fitter condition to absorb the "ferriferous chyle." And yet, if so, the drinking of a single glass of water would probably be sufficient to swell out the corpuscles again, and thus put a stop to the process. It is just possible that a Cathartic may be serviceable by purging away from the blood some effete matters, as Sulphuretted Hydrogen, formed by the continual decomposition of the tissues, which would have hindered the operation of the Chalybeate in the blood, by decomposing it.
The use of Iron may, I think, be summed up by saying that it cures Anæmia. In this way it may benefit, and sometimes cure, other disorders, in which Anæmia is apt to be a prominent symptom. Such are Amenorrhœa, Scrofula, Cancer, chronic Ague, Hysteria, Chorea, and Bright's disease of the kidney. But it seems that it can never be used advantageously in these disorders, when they are unattended with Anæmia; nor even then is it to be preferred to the other remedies specially appropriate in each case, but ought rather to be conjoined with them. Cancer, and granular kidney disease, may perhaps be alleviated, but are seldom cured. In Chorea, Arsenic or Quinine may be used, with or without Iron. Aloetic purgatives may be advantageously conjoined with Chalybeates in Amenorrhœa and Hysteria. Their use may be accompanied by cold affusions, or by some antispasmodic stimulant. In Scrofula the Iodide of Iron affords us a valuable double remedy. In chronic cases of Ague, when accompanied with Anæmia, as is often the case, Iron may be prescribed with advantage.
In general Anæmia, an occasional purge, a generous diet, with good air and exercise should be combined, if possible, with the Chalybeate treatment.
Ord. VI. Solvents.
(Antilithics.