Like the mineral acids generally, the nitromuriatic may often be used advantageously in general debility with enfeebled digestion. For the special affections in which it may be thus employed as a tonic to the digestive organs, the reader is referred to the therapeutic applications of sulphuric acid. (See page 359.) The condition under which, in these affections, it may be employed preferably to other acids, is when, with the general debility, and that of the stomach in particular, there is conjoined a torpid condition of the liver, as evinced by the want of bile or its deficiency in the feces. In other respects, acting in these cases probably through the excess of the nitric acid it contains, it is identical in its effects with that remedy separately administered.

I am much in the habit of using nitromuriatic acid in certain cases of diarrhoea, chronic enteritis, and dysentery, and find it occasionally extremely useful. The disease, after lingering long under various treatment, speedity begins to amend, and goes on regularly to convalescence, under the use of the remedy, which I generally give combined with an opiate. That the result is not due exclusively to the latter, is proved by the fact that it has been given previously, and in other forms of combination, without any curative effect. The cases referred to are unattended with fever or heat of skin, and are characterized by a relaxed condition of the system, and apparently of the alimentary canal, which appears to indicate a tonic treatment. I am disposed to think, however, that the remedy operates, in these cases, not only as a tonic, but also by an alterative influence on the mucous surface, and perhaps upon the blood, the nature of which is not yet understood.

The applicability of nitromuriatic acid to the treatment of diseases of the liver was a beautiful discovery of Dr. N. Scott, of Bombay. That practitioner, having obtained very beneficial effects from nitric acid in hepatic affections, and made known the results of his treatment, and being surprised at a want of coincidence in the experience of other practitioners with his own, was led to make particular inquiries into the cause. He found that the nitre, out of which the acid employed by him in India was prepared, contained a considerable proportion of chloride of sodium, and consequently yielded muriatic acid along with the nitric; so that in fact he had been using nitromuriatic acid in his cases, and not the pure nitric. He was, therefore, induced to try the compound acid, and found his conjecture verified by the result.

Nitromuriatic acid appears to act as a stimulant to the secretory function of the liver, and as an alterative in its morbid conditions, very much in the manner of mercury, though in an inferior degree. It differs from that remedy in being wholly inapplicable to acute inflammatory affections, or high vascular irritation, with active congestion of the organ But when the secretory function is deficient, or wholly suspended, in consequence of mere torpor or debility of the gland, nitromuriatic acid acts often very advantageously; and if, with this condition of the liver, there are conjoined considerable general debility, an anemic or otherwise depraved state of the blood, and depression of the digestive function, it should even be preferred to the mercurials, as it tends to repair, instead of aggravating, as the latter remedies too often do, the coincident affections. In chronic inflammation of the liver, also, the remedy is peculiarly useful, under the same circumstances. In cases, moreover, in which mercury has been tried without satisfactory results, or insurmountable prejudice exists against it, or idiosyncrasy of the patient forbids its use, nitromuriatic acid should be resorted to as the best substitute. In the suppurative stage of acute hepatitis, the same remark is applicable. Of course, in the jaundice, dropsical affections, and general cachectic stale of system, so often associated with, and in great measure dependent on hepatic disease, much good may be expected from the remedy, properly employed, and sufficiently long continued. One practical remark is applicable in all these cases; namely, that nitromuriatic acid and mercury, however apparently coindicated, should never be administered together, at least with any quantity of the mercurial larger than a small fraction of a grain; for there is danger of the production of corrosive sublimate, and, consequently, of all the mischief which that poison is capable of producing. I have been informed, on sufficient authority, of a case of death which speedily followed the joint exhibition of nitromuriatic acid and calomel, with violent pains in the stomach and bowels, vomiting, purging, etc.

As a purifier of the blood, nitromuriatic acid may be used advantageously in depraved states of health, attended with ulcerative affections of the skin, or certain eruptions, as ecthyma, rupia, porrigo, etc.; in the purulent infection consequent on the absorption of degraded and disintegrated pus, and in the somewhat similar condition of the system in gangrene. In all these cases, it probably acts jointly by the tonic influence of its acid ingredient on digestion, and the general alterative influence of the portion absorbed.

In the oxalic lithiasis it is certainly an admirable remedy. Suggested first, I believe, by the late Dr. Bird, of London, instead of the nitric acid recommended by Dr. Prout, it has come into general use, and often produces the happiest results. I have repeatedly used it in cases characterized by an abundance of oxalate of lime in the urine; and, I believe, in no instance have known it to fail in correcting, or much diminishing that symptom; while, at the same time, the constitutional symptoms have often undergone a similar amelioration.

There is a special morbid condition, which I have occasionally met with, and have for many years been in the habit of combating, by means of this remedy, with the happiest success. I do not know that I can convey an accurate idea of this condition to the reader, but it is sufficiently well characterized to my own observation. There is a failure of the appetite, a slight fur upon the tongue, which, however, remains moist, a tendency to constipation, a cool, moist, and relaxed surface, and a pulse rather feebler, perhaps, than in health, sometimes a little accelerated, but not strikingly abnormal in any way. With these symptoms are frequently conjoined an offensive breath, general languor, and a remarkable and apparently causeless depression of spirits, with perverted feeling, sometimes almost approaching insanity. I have attributed this condition to a depraved state of the blood, dependent probably on defective digestion and assimilation. It may continue for weeks without abatement; but, under the use of nitromuriatic acid, begins to improve in a few days, and, in a period of time varying from two or three weeks to some months, often yields entirely. Since the practice of chemical and microscopical investigation of the urine has come into vogue, circumstances have prevented me from investigating the state of the secretion in this affection unless in a few instances; and, in all of these, oxalate of lime was noticed in the urine.