Acidum Nitricum. Aqua Fortis. 3 HO, 2 NO5. Prep. By the action of Sulphuric Acid on Nitrate of Potash. Comp. Dry Nitric Acid 80, Water 20, in 100 parts; or 2 Eq. of Dry Nitric Acid = 108, + 3 Eq. Water = 27 = 135. Sp. Gr. 1.5.

Dilute Nitric Acid. Acidum Nitricum Dilutum. Prepared by mixing 2 fl. oz. of Nitric Acid with 13 fl. oz. of Distilled Water. Sp. Gr. 1.101. Contains 15 per cent, of Dry Nitric Acid. The Dilute Acid of the Lond. Pharm. contained 12 per cent. of Dry Nitric Acid.

Med. Prop. and Actum. Strong Nitric Acid is a powerful caustic and escharotic, communicating a permanent yellow stain to the cuticle. The dilute acid, in doses of ex. - xx., is antalkaline, tonic, alterative, and refrigerant. If continued for a long period, it causes salivation; it has also apparently a more direct action on the liver than the other acids, but it disagrees with the stomach sooner than Sulphuric Acid. It is an excellent alterative, after long courses of Mercury, renovating the strength, and improving the tone of the system in a remarkable manner. As it acts injuriously on the teeth, any medicine containing it should be sucked through a quill or glass tube, and. the mouth should be rinsed out with an alkaline solution after each dose. As a fumigating and disinfecting agent, it is very valuable, though perhaps inferior to Chlorine; the vapour may be readily developed by pouring one part of Nitric Acid over one part of the Nitrate of Potash, placed on a heated sand-bath.

Offic. Prep. 1. Acidum Nitricum Dilutum. (See above.) Dose, ev. - exxx., freely diluted.

2. Acidum Nitro-Hydrochloricum Dilutum

(See Nitro-Hydrochloric Acid.)

Dose of Strong Nitric Acid, e,ss. - eiij., freely diluted.

Incompatibles. Alkalies, their Carbonates and Acetates; most earths, and their Oxides; Sulphurets and Cyanurets; Sulphate of Iron, Charcoal, Sugar, Alcohol, Spirit, and volatile oils.

1890. Therapeutic Uses

Calculous Disease. In the Alkaline and Phosphatic Diathesis, Nitric Acid may be employed with advantage. Sir B. Brodie * speaks highly of its value. ''In extreme cases," he observes, "you may give exxx. - xl., or even more, of the strong acid, sufficiently diluted with syrup and water, in the course of the day." The effect of these large doses in correcting the alkaline quality of the urine is very remarkable. He also employed it as a direct solvent, by injecting into the bladder a mixture containing one drop of the strong acid in f j. of water. From numerous experiments, he * came to the conclusion that a calculus, composed externally of the phosphates, may be acted on by this injection, so as to become gradually reduced in size, while it is still in the bladder of a living person. It is now rarely employed.

* On Diseases of the Urinary Organs, p. 218.

1891. In Chronic Inflammation of the Bladder, when the severity of the symptoms have abated, Sir B. Brodie states that for many years he has employed weak injections of Nitric Acid. The strength employed at first is 1 minim of the strong, or 10 of the dilute acid, in fj. of distilled water; but afterwards the quantity of the acid may be doubled. It should never be employed if any active inflammatory symptoms are present, nor of a greater strength than the above; it should not be retained more than forty seconds, nor be repeated oftener than once every two days at first, and daily afterwards. It should always be discontinued if it give pain. With these precautions, he considers it a valuable remedy and free from danger.