Acidum Hydrochloricum. Hydrochloric Acid Gas, HC1, dissolved in Water. Muriatic Acid. Spirit of Salt. Sp. Gr. 1.17.

Acidum Hydrochloricum Dilutum. Dilute Hydrochloric Acid. Prep. A mixture of 3 fl. oz. of Hydrochloric Acid with 8 fl. oz. of Distilled Water. Sp. Gr. 1.05.

Med. Prop. and Action. The strong acid is a powerful caustic and escha-rotic. For internal use, the dilute acid, in doses of ex. - xx. in any bland fluid, acts as an antalkaline, stimulant, tonic, and mild laxative. In continued doses it is alterative and tonic, improves the tone of the digestive organs, and is regarded by Dr. Paris || as an effectual preventive to the generation of intestinal worms. If continued too long, it produces effects similar to those of the other mineral acids. (See Acids, part ii.) From its injuirous action on the teeth, it is advisable to wash the mouth out with an alkaline solution

* Ranking's Abstract, vol. xv. p. 536. Med.-Chir. Rev., Oct. 1844. Lancet, March and April, 1849.

§ Surg. Obs. on Diseases of the Joints, Lond. 1828. || Pharmacologia.

immediately after its employment, either internally, or locally to the fauces. As a disinfectant and fumigant, Hydrochloric Acid was first recommeced by Guyton Morveau in 1773, to disinfect the cathedral of Dijon; the air of which had become intolerable from the stench emanating from the bodies buried beneath the building. He employed a mixture of (5 lbs. of common salt and 2 lbs. of Sulphuric Acid. The Hydrochloric Acid fumes set free deprived the air of all unpleasant odour, and in four days afterwards public worship was held in the building as usual. He recommends the following proportions: 15 parts of common salt and 12 of Sulphuric Acid. The salt is to be placed on flat earthen dishes on a sand-bath, and the whole acid added at once. In an inhabited house, the acid should be added gradually, and the sand-bath dispensed with (Dr. J. Brown *). Its disinfecting properties are, however, inferior to those of Chlorine.

Dose of Acid. Hydrochlor. Dil. ex. - exxx. freely diluted.

Incompatible*. Alkalies and their Carbonates, Tartrates, Citrates, Nitrates, and Sulphates; Tartar Emetic; Nitrate of Silver; Acetate of Lead; and most earths and oxides.

1518. Therapeutic Uses

Calculous Affections. In the Oxalic Acid Diathesis, Dr. Prout prefers in some eases the Hydrochloric to the other acids. It may be given alone or combined with tonics, and should be persevered in for a month, or until the Lithate of Ammonia or Lithic Acid begins to appear in the urine, when its use should be suspended. The Nitro-Muriatic Acid is, however, more generally efficacious. The same remarks apply to the Cystic Oxide Diathesis. In the Phosphaiic Diathesis, the alkaline or alkalescent condition of the urine requires to be corrected by acids; and of these, the Hydrochloric has been found the most generally beneficial. Its effects require to be carefully watched. In many instances, however, too much irritation exists to allow the administration of this remedy, in which cases opiates are clearly indicated. Of the acid, ev. - x. thrice daily, will generally be sufficient. Mr. Balman relates a case of Phosphatic Calculus, which was cured by injecting into the bladder a mixture of gutt ij. of the acid in fiv. of water, always taking care to wash out the bladder previously with warm water. It gave rise to no unpleasant symptoms. Given internally, Dr. Christison considers that it acts by correcting the phosphatic diathesis, rather than by acting directly on the urine.