ACID

by distilling common vinegar; but as a portion of the acid is lost bythe process, it is weaker. Properties and use the same as vinegar.Enters into Potass. Acet. L. E. D. Acet. Ferri. D. Liq. Amnion.Acet. L. E. D. Liq. Plumb. Subacet. L. D. Acet. Colchici. L.Emplast Ammoniaci. L. Oxymel. L. D. Oyxm. Colchici. D.Plumbi Superacet. L. E. D. Acetum Scill. L. E. D.

Acidum Aceticum Fortius b Ligno Distillatum. L. PyroligneousAcid. In the manufacture of charcoal from wood in iron retorts, anacid is produced, by twice redistilling, saturating with quick-lime, evaporating to dryness, and then decomposing the impureacetate of lime thus formed by sulphate of soda. The sulphate oflime and acetate of soda thence resulting are then decomposed bysulphuric acid; and by distilling, a pure, perfectly colourless acid, freefrom empyreuma, is procured. It can be had from the manufacturersof any degree of strength, but that directed by the London Collegeis to be of sp. gr. 1-046, (but this is not a good test of its strength,)or six times as strong as diluted acetic acid, or distilled vinegar.Medicinally it is said to be useful as a lotion in cutaneous affectionsrequiring stimulants, such as tinea, lepra; and in ulcers and sinusesfrom carious bones, &c.It is strongly antiseptic, and is an excellent preservative from putre-faction, in curing hams, tongues, &c.Enters into Potassa? Acetas. L. E. D. Plumbi Acetas. L. E. D.

Acidum Arsenicum. Arsenic Acid. Procured by distilling the whiteoxide of arsenic with nitrous acid. Its properties are much the sameas the oxide. See Arsenici Oxydum.

Acidum Benzoicum. L. E. D. Benzoic Acid, or Flowers of Benja-min. Procured by subliming a pound of benzoin in a glass vessel ina sand-bath beginning with a heat of 300° and increasing it. Theportion sublimed is then to be removed into blotting-pajier, pressed,and re-sublimed with a heat not exceeding 400°.Decomposition. The acid is disengaged by the heat, and passes over,leaving the gum as a residuum. It requires care to prevent empy-reuma arising during the process.Medicinally it is fragrant, hot, but agreeable to the taste. Stimulant

in doses of gr. x to ^ss, but seldom used.Enters into Tinct. Opii Amnion. E. Tinct. Camph. comp. L. D.

Acidum Boracicum. P. Boracic Acid. Sedative and antiseptic.Little used.

Acidum Citricum. L. E. D. P. Citric Acid, White Acid of Lemons,or Concrete Lemon Juice. Procured by adding any quantity oflemon or lime juice to finely-powdered chalk till effervescence ceases,when an insoluble citrate of lime will be formed, which is well