THERAPEUTIC USES OF IRON. The use of iron in the cure of disease dates from a very early period. Pliny speaks of its medicinal effects, and there is reason for believing that it was administered several centuries before his time. But Sydenham was the first to point out its most important therapeutic property, its blood-restoring power. " To the worn out and languid blood," he says, "it gives a spur or fillip whereby the animal spirits which before lay prostrate or sunk under their own weight are roused and excited."
The blood is composed of a fluid wherein float roundish red bodies, the blood corpuscles, which play a leading part in those tissue changes essential to life. Each corpuscle consists of a stroma permeated by a red fluid, haemoglobin, which has the remarkable property of readily combining with either oxygen or carbonic acid, but so loosely that under slightly altered conditions these gases are as readily separated from it. In the lungs the corpuscles, through their haemoglobin, take up oxygen which they carry to all parts of the body. But in the presence of the vital pro-cesses of disintegration and repair constantly going on in the tissues, the corpuscles yield up the oxygen they have brought, and supply an element necessary for these pro-cesses. Having got rid of the oxygen, the haemoglobin then unites with the carbonic acid produced by tissue disinte-gration, and the corpuscles thus reladen carry their burden back to the lungs, and discharge there the carbonic acid, taking up anew a supply of oxygen. If the haemoglobin of the blood fall below a certain standard, the supply of oxygen necessary to healthy tissue changes in brain, nerve, muscle, &c, becomes too limited, and the changes will be imperfectly performed; hence defective vitality, general or loca1. Now the ingestion of iron increases the hsemo-globin supply when it is defective; it promotes the pro-duction of blood corpuscles, and causes each corpuscle to carry with it more haemoglobin; hence the health-giving power possessed by this metal. The exact method in which the increase in red colouring matter is brought about we do not know, but in the fact that iron forms an essential constituent of haemoglobin we have some clue to its utility.
Anaemia or spanaemia is the name given to that condition in which the red colouring matter of the blood is below the normal amount. It is indicated by pallor of skin and mucous membranes, and by a depressed condition of brain, of muscle, and of the tissues generally. A beating headache is often present, sustained mental or physical exertion is difficult, palpitation and breathlessness are sources of in-convenience ; in the female the uterine functions are often in abeyance. By a chalybeate course we can usually restore to the blood its due supply of haemoglobin, and cause the gradual disappearance of all these symptoms.
It would be impossible here to enumerate all the special forms of spansmia in which iron is prescribed. It will be sufficient to point out the leading conditions under which it may be given with every hope of advantage, and those in which it usually fails to do good. First of all, it is of marked benefit in the spanaemia of young females, which is often accompanied by a faint greenish or yellowish discoloration of the skin. Chlorosis is the name usually given to this condition. Here iron almost unfailingly though slowly removes the pallor, breathlessness, and palpitation, increases mental and physical vigour, and restores the uterine functions. Where the blood has been impoverished by haemorrhages, want of proper food, or exposure to bad hygienic conditions, iron rarely fails to improve its character, provided the causes of such impoverishment are removed. In convalescence from many illnesses, iron is em-ployed with advantage, and it aids recovery from such constitutional diseases as rickets and scrofula by its restorative effect on the blood, sometimes too in syphilitic cachexia it is of service. On the other hand, in the obscure disease called pernicious anaemia, the cause of which is so far unknown, but in which the deficiency of haemoglobin is extreme, iron is rarely even of temporary service. It is generally useless too in the spanaemia attendant on advancing consumption where the temperature is high; some physicians indeed hold that in such eases it is injurious, because it increases temperature. In chronic diseases leading to spanaemia, where the cause of the poverty of blood is continuously present, iron is often of but little service. Such is the case in cancer and most of those emaciating ailments which tend naturally to a lethal termination. But in valvular disease of the heart, iron though not curative often helps to prolong life and relieve suffering, for by enriching the blood it spares the heart some of its labour, and at the same time strengthens the cardiac walls. In Bright's disease too, which is often accompanied with bloodlessness, iron is a most valuable medicine in prolonging life even though incapable of saving it.
Hitherto we have spoken of iron only in its capacity of a strengthening agent acting through its power of stimulating the production of haemoglobin, but it may be beneficial in other ways. It is supposed to augment the production in the blood of that active oxydizing agent ozone, but of this we have little or no proof; there is, however, considerable probability that the iron which exists as an albuminate in the blood serum has some direct tonic effect on the tissues through which it circulates ; and the astringent pre-parations, such as the sulphate, are most effective in bracing the gastro-intestinal mucous membrane when it is relaxed.
Iron is of use in some diseases of special organs and systems, partly perhaps from its general tonic effect, but in part too no doubt from some local nutritive action which it has. In neuralgia, for example, it is sometimes curative, more certainly so, however, if combined with quinine. In chorea, or St Vitus's dance, too, it is of value, especially when combined with arsenic. On the digestive organs chalybeates have at times a good effect, some forms of dys-pepsia and diarrhoea being favourably influenced by them. Iron too is of service often in the nocturnal incontinence of children, and is often given as an emmenagogue. In gout, plethora, and most febrile ailments, the administration of iron is usually held to be injurious, but in erysipelas the administration of half drachm doses of the tincture of the perchloride of iron every four hours has been highly lauded, and Dr Russell Reynolds advocates the use of similar doses in acute rheumatisms. Iron is valued for the astrin-gent effects of some of its preparations on parts with which they come in contact, as well as for its good effects on the blood and various organs after ingestion.
The tincture of perchloride of iron is used as a styptic to stop bleeding from the gums or from leech bites, or other slight haemor-rhages. Sometimes too it is of service locally applied in bleeding of a more serious character, but it is a strong irritant to the parts with which it comes in contact. One part of the tincture of the perchloride mixed with three of water is sometimes injected up the nostril to check persistent nose bleeding. Lint moistened with the tincture is also used as a plug for the same purpose. For stopping haemorrhage after confinement, the plan introduced by Dr Barnes of injecting a solution of perchloride of iron into the uterus is frequently followed with the greatest advantage. The perchloride and sulphate of iron may be given to check haemorrhage from the stomach, and these salts have likewise been used to decrease the discharge in gonorrhoea and leucorrhcea. The local application of the tincture of perchloride of iron in diphtheria has been highly recommended, and a very dilute solution is sometimes used as a rectal injection to destroy thread-worms.
As a medicine iron is used in many forms and combinations, and thirty-three of these are described in the British Pharmacopoeia. The metal itself, finely divided, is often administered in 1 or 2 grain doses,ferrum redactum the preparation is called,and lozenges are made of it, each containing 1 grain of reduced iron. The vinum ferri or solution of iron in wine is probably the most ancient of all iron preparations. Of the oxides, the peroxide and the magnetic oxide are officinal. The former was in early times known under the name of saffron or crocus of iron, and was much used ; but now more soluble preparations of iron are usually pre-scribed. Recently precipitated peroxide in a moist condition is one of the best antidotes for arsenical poisoning if given in quarter to half ounce doses. The carbonates of iron readily undergo oxidation unless mixed with sugar, which therefore enters into all the phar-macopceial preparations of iron, the saccharated carbonate of iron, the pill of the carbonate of iron, and the compound iron mixture. Perhaps the most commonly used and the best known astringent preparations of iron are the combinations of this metal with vege-table acids, the ammonia citrate of iron and the tartrate of iron, which are given in 5 to 10 grain doses, the former too in the form of wine (vinum ferri citratis). The combination of citrate of iron and quinine is an exceedingly valuable preparation, and is given in 3 to 5 grain doses. The acetate of iron is somewhat astringent, but, though officinal, is very rarely used. The sulphate and per-chloride of iron are powerful astringents, constricting the tissues with which they come in contact. Several preparations of these salts are officinal. Their use as local applications has been alluded to ; internally they are given instead of the non-astringent chaly-beates, when a tissue-bracing as well as a blood-restoring effect is desired. They are more constipating than the non-astringent chaly-beates. The dose of the solution and tincture of perchloride of iron is from 5 to 20 minims. The sulphate is given in 1 to 3 grain doses. Iodide of iron, in the form of pill or syrup, is specially used in cases of struma. The phosphate of iron and its syrup are of the greatest value when given to weakly and rickety children.
All the above-named iron medicines are officinal. Of those not mentioned in the Pharnwcopceia, two only need be alluded tosolu-tion of dialysed iron, which of all preparations is perhaps the least liable to disagree with the stomach, and solution of the magnetic phosphate of iron in citric acid, commonly known as Lightfoot's steel, one of the most agreeable of the acid solutions of iron.
Many mineral waters contain iron. In most it exists as a car-bonate, but in one of the springs at Harrogate as chloride. Chaly-beate waters are in suitable cases the most effective of blood tonics.
Ingestion of iron in all forms causes the stools to become black. This arises from the fact that, when iron is taken, but little is absorbed ; the rest passing into the intestinal canal is converted into the black sulphide by the sulphuretted hydrogen present there. The discoloration is devoid of all significance. The evil effect of iron preparations on the teeth has been much exaggerated. The acid chalybeates, if taken in a concentrated form, may indeed do harm, and all iron medicines tend to blacken the teeth somewhat, but by washing the mouth out with water after taking them the possibility of injury is readily prevented. (D. J. I..)