The use of nitric acid as a tonic is very nearly the same as that of sulphuric acid. Like that, it is peculiarly applicable to the debility of convalescence, with want of appetite, and a disposition to sweat at nights; though not perhaps equally efficient in correcting excessive perspiration. I have occasionally met with cases of fever, from which the recovery seemed very slow; the pulse remaining rather frequent, especially in the latter part of the day, the tongue somewhat furred, and the appetite feeble or wanting; and this state of things continuing for days with little or no change. Under such circumstances, nitric acid, given in small doses every two or three hours, has seemed to answer an excellent purpose in hastening and confirming the convalescence.

It has also been used with asserted advantage in fevers generally, being prescribed partly as a tonic, and partly as a refrigerant in those of feeble action, and as a refrigerant alone, in such as require no supporting treatment; but, in cases of this kind, having had little faith in its peculiar efficacy, I have not been in the habit of using it; and can, therefore, say nothing from experience of its virtues. I have already explained how it is possible that it may produce a refrigerant effect. Dr. Bedford Brown, of Yancey ville, N. C, has found it highly advantageous in the adynamic state of remittent fever, in connection with sulphate of quinia, to which, he thinks, it "certainly added efficacy." He began with three drops every six hours, and gradually increased even to ten drops in cases of peculiar intensity. (Am. J. of Med. Sci., Jan. 1860, p. 49.) Dr. Wm. A. Hammond states, as the result of his treatment of 41 cases of intermittent, 32 by nitric acid, and 9 by sulphate of quinia, that the former was equally successful with the latter. He gave ten drops of the acid three times a day. (Ibid, April, 1861, p. 606.) It had previously been used as an antiperiodic by Drs. E. T. Bailey and Geo. Men-denhall, of Indiana. (U. S. Dispensatory, 12th ed).

Some have supposed it to have an alterative influence on the liver, and to be useful in chronic inflammation of that organ. Generally it has altogether failed of making any useful impression in such cases, and certainly cannot be relied on. Nevertheless, it may occasionally do good, through the generation of nitromuriatic acid in the primae viae.

Of its asserted specific virtues in secondary syphilis, scrofula, and various eruptive affections characterized by a depraved blood, as impetigo, ecthyma, rupia, etc., I have seen nothing which might not be ascribed to its simple tonic action upon the digestive organs, and to the consequent improvement in sanguification and nutrition. Nevertheless, there may possibly result from its chemical reactions within the system, substances having in some degree the peculiar virtues referred to; and the statements as to its efficiency made by respectable practitioners would tend to confirm this view. It is, however, acknowledged to be inferior to other medicines in the cure of the affections mentioned, and, if used at all, should be so as an adjuvant merely.

In diarrhoea, and dysentery, and the ordinary forms of cholera, it has been highly recommended; and, in the form of what is called Hope's mixture, was at one time in great repute. This consisted of nitrous acid, camphor water, and laudanum. Much stress was laid upon the choice of nitrous preferably to nitric acid. I have already shown that this preference was unfounded. I have employed this mixture in the affections above referred to, but generally with little greater effect than could be ascribed to the laudanum and camphor water. The acid often provoked irritation and pain in the stomach or bowels. Nevertheless, there are cases of bowel affections in which the acid appears to do good. I consider it wholly inapplicable to acute cases, with severe pain in the bowels, and febrile symptoms. The circumstances under which it has appeared to me useful, are a certain degree of general debility, without heat of skin, with no considerable pain, and evidences of a feeble or relaxed condition of the mucous membrane, which disables it from resuming its healthful functions. In such a condition, whether the affection be in the early or advanced stage, and whether it have the form of diarrhoea or of dysentery, the combination above referred to may prove useful; but it is, I think, in cases of diarrhoea following cholera infantum that it has proved most beneficial in my hands. In ordinary cholera morbus, other methods an so uniformly successful, that I have never considered myself justified in omitting them in order to try nitric acid.

Epidemic cholera has also been treated by nitric acid, but I believe with no peculiar success.

In hooping-cough it was recommended by Dr. Arnoldi; and Dr. Geo. D. Gibbs considers it as a most efficient remedy. In a treatise by the latter, published in London, a.d. 1854, he states that "it not only arrests the paroxysms, and removes the hoop, but shortens the disease almost as effectually as quinine does intermittent fever." (Lond. Med. Times and Gaz., July, 1854, p. 118.) Dr. Arnoldi adds as much of the acid to water, sweetened with sugar almost to the consistence of syrup, as will give it the sourness of pure lemon-juice. Of this preparation he gives to a child one year old a dessertspoonful every hour, to an adult a tumblerful during the day. It is useless to speculate upon the mode of action of the remedy, till further experience shall have established its efficacy. Hooping-cough is sometimes protracted in consequence of a state of debility into which the patient is apt to fall, and which is relieved by tonics. Thus far nitric acid may no doubt prove useful; but much more is claimed for it by the practitioners above referred to.

Several cases of spasmodic asthma very promptly yielded to the use of the acid, in the practice of Dr. T. S. Hopkins, of Bethel, Georgia. Most if not all of the cases were of young children. He gave from three to five drops of the acid three times daily. (Am. Journ.of Med. Sci., N. S., xx. 549).

As an antilithic, the remarks made upon sulphuric acid are precisely applicable to the nitric. It will be remembered that it is in the phos-phatic diathesis that the remedy is specially indicated.

As a local remedy, nitric acid has been used to stimulate feeble ulcers. to remove the callous edges of the obstinate, and to correct the morbid action of the ill-conditioned and phagedenic. It has also been recently employed, with great asserted advantage, as an application to prolapsed anus and piles.* Sir B. Brodie succeeded in dissolving a phosphatic calculus, by injecting into the bladder, every two or three days, for a time varying from fifteen to thirty minutes, water acidulated with nitric acid, in the proportion of two and a half minims to a fluidounce.