Glacial Acetic Acid. Mono-hydrated Acetic Acid, HO, C4H3Oa. Prepared by decomposing fused Acetate of Soda with Sulphuric Acid. A colourless liquid, with a pungent acetous odour, converted, when cooled to nearly 32°, into colourless prismatic crystals. Sp. Gr. 1 065, which is increased by adding to the acid 10 per cent of water.

Acidum Aceticum. Acetic Acid. Pyroligneous Acid. Prepared from wood by destructive distillation, and containing 28 per cent. of anhydrous Acetic Acid. Sp. Gr. 1.044.

Acidum Aceticum Dilutum. Dilute Acetic Acid. Prepared by mixing one pint of Acetic Acid with seven pints of distilled water. Sp. Gr. 1006.

Med Prop. and Action. Glacial Acetic Acid is only employed as an external agent; it is a very powerful caustic. Applied to the skin, it produces intense redness and pain, followed by rapid vesication. It must be used with caution, as its action extends to a considerable depth, and a severe sore is produced. It may be used as a Vesicant where the absorption of Cantharadine would be prejudicial, as in some affections of the kidneys. (Garrod.) Glacial A Acid dissolves Cantharadine freely, and the solution so prepared may be used for rapid blistering. Acetic Acid may be applied externally as a Rubefacient, Vesicant, Escharotic, and Antiseptic. Administered internally to man or animals, the concentrated forms of Acetic Acid act as powerful corrosive and irritant poisons. Dilute Acetic Acid may be used internally in the same manner as Vinegar as a Refrigerant and Astringent.

Offic. Prep. Oxymel(Clarified Honey oz. xl; Acetic Acid fl. oz. v.; Distilled Water fl. oz. v.) Dose,fl. drm. j. - fl. oz. j.

Dote of Acetic Acid, eiij. - exv. Of Dilute Acetic Acid. exxx - fl. drs. if.

Incompatibles Alkalies and their Carbonates, Alkaline Earths and then-Carbonates.

24. Therapeutic Uses

In Tinea Capitis, the local application of the strong acid is recommended by Mr. Wigan. The first application is with the acid, diluted with three times its weight of water. On being applied, a number of spots previously looking healthy become red patches; then, with a piece of sponge tied to the end of a stick, each spot is to be imbued thoroughly with the strong acid for three or four minutes. A single application is sufficient, in the majority of cases. A crust grows up with the hair, which may be removed as soon as a pair of fine scissors can be introduced beneath it. Mr. Erasmus Wilson speaks favourably of a similar mode of treatment repeated once in the week, and in the intermediate days using some mildly stimulating ointment.

* Lect. on Brit. Pharm. Med Times and Gaz January 30, 1864. Medical Gazette, Sept. 15, 184a. Diseases of the Skin, p. 448.

25. In Psoriasis, Dr

Cummin* states that his trials with strong Acetic Acid have been highly satisfactory; the diseased cuticle separating in flakes, and a new surface being exposed, of a much more healthy character. The application of the acid is hot and painful, especially when there are excoriations and fissures; but these should be protected by some mild cerate. The acid requires, in most cases, to be repeated twice or thrice. In obstinate cases of Lepra, much benefit has been derived from the use of baths, acidulated with Acetic or Pyroligneous Acid.