"Take of sesquicarbonate of ammonia, four ounces and a half; distilled vinegar, four pints. Add the sesquicarbonate of ammonia to the vinegar to saturation."

Aqua Acetatis Ammoniae, Edin. Water of Acetate of Ammonia,

"Take of carbonate of ammonia in powder, any quantity. Pour upon it as much weak acetic acid as will exactly saturate the ammonia."

Ammoniae Acetatis Aqua, Dub. Water of Acetate of Ammonia.

"Take of carbonate of ammonia, one part. Add by small portions, with frequent agitation, as much distilled vinegar as will saturate the ammonia, viz. about thirty parts. This may be ascertained by means of litmus."

Syn. Acetate d'ammoniaque liquide (.F.), Essigsaures Ammonium liquor (G.), Liquore di Minderero (I.).

The sesquicarbonate of ammonia employed for this preparation is decomposed by the acetic acid of the distilled vinegar; which, combining with the ammonia, forms an acetate that remains dissolved in the water, while the disengaged carbonic acid flies off in the form of gas, exciting effervescence. In our experiments, distilled vinegar of a specific gravity of 1.007 required 320 grains of the sesquicarbonate to saturate a pint.2 Owing, however, to the variable proportion of acid in distilled vinegar, this preparation cannot be obtained of an uniform strength; and provided it be accurately neutralized, which is easily known by using litmus and turmeric paper, its uniformity of strength is of little importance. If it be not accurately saturated, some of the metallic salts, particularly those of antimony, which are often ordered in conjunction with it, are decomposed.

Qualities. - This solution is inodorous; has a slightly nauseous taste; and, when made with pure materials, is limpid and nearly colourless. It is decomposed by the fixed alkalies, the strong acids, alum, magnesia, lime-water, sulphate of magnesia, bichloride of mercury, nitrate of silver, the sulphates of zinc, copper, and iron, and acetate and diacetate of lead, which are consequently incompatible in formulae with it.1

1 Aqua ammoniae acetate, P. L. 1787.

2 The mercury of a thermometer, the bulb of which was immersed in the solution while effervescing, sunk five degrees.

Medical properties and uses. - As a diaphoretic it is in common use in febrile diseases; and may be combined with opium, camphor, antimonials, or nitrate of potassa. It is necessary to assist its determination to the skin with plentiful dilution, and a moderate degree of external heat; for by free exposure to cool air it excites the kidneys, instead of opening the skin. Externally it is employed as a discutient; as a lotion to inflamed surfaces; and when diluted with rose water, holding in solution a small portion of opium, it is an excellent collyrium in chronic ophthalmia; and still more largely diluted, is occasionally used as an injection in the commencement of gonorrhoea. In the crystallized form it has proved beneficial in painful menstruation. I have used it with the best effect as a lotion in porrigo, affecting the scalp. The ordinary dose is from f 3 iv. to f 3 xij., given every three or four hours.