Aqua Ammoniae Fortior. U. S. - Liquor Ammonio Fortior.

U. S. 1850, Br.

Preparation and Properties. This is prepared by receiving gaseous ammonia in water, until it becomes nearly saturated. As directed by the U. S. Pharmacopoeia, the preparation has the sp. gr. 0.900 and contains 26 per cent. of ammonia; the British solution has the sp. gr. 0.891, and contains 32.5 per cent. The strongest possible solution is said to be of the sp. gr. 0.875 at 50° F. As found in the shops, however, it is seldom of the officinal strength; and, if it be so at first, will scarcely remain so long, when at all exposed to the air, in consequence of the rapid escape of ammonia. it should be kept in well-stopped glass bottles in a cool place.

It is a colourless liquid, of an insupportably pungent odour, and of a burning, acrid, alkaline taste, when sufficiently diluted to be admitted into the mouth. it has in a high degree all the alkaline properties.

Effects on the System

We have here to consider only its local effects. When applied to the surface, if of the officinal strength, it is so rapidly caustic, and on exposure emits suffocating emanations so copiously, that its use in an undiluted state is very inconvenient. For application as a vesicating agent, it should be reduced, if of unimpaired strength, by the addition of about an equal measure of water; but, as often found in the shops, it is comparatively so feeble that it may be employed undiluted. In the dilute form, it first reddens, then vesicates, and ultimately cauterizes, and all generally within a period of fifteen minutes. For its vesicating effect, it may be used when cantharides cannot be employed on account of the extreme susceptibility to strangury, and when it is desirable to raise a blister very promptly, as in cases of great and sudden prostration from gouty spasm in the stomach, anginose affections of the heart, the sinking spells of low fever, etc., and intolerable neuralgic or spasmodic pains. it may be employed, also, to obtain quickly a denuded surface for the endermic application of medicines, in cases of great emergency. it may be most conveniently applied by saturating with it a compress of folded linen, or a piece of dense coarse flannel, which must be covered with a thick towel. For procuring a small blister, the top of a large wooden pill-box, or a large watch-glass, may be filled with patent lint, saturated with the liquid, and then inverted and pressed upon the skin, so as to prevent the escape of the gas. A blister is produced usually within ten minutes, and sometimes so soon as five, or even three minutes; after which it should be removed, in order to avoid cauterizing.

A vesicating ointment may be made by mixing the stronger solution of ammonia with lard and almond or olive oil, in the proportion of one part of the solution to two of the oily matter. For the precise mode of preparing it, see the U. S. Dispensatory (12th ed., p. 99). it may be kept in a glass bottle well stopped, and used as required. it will produce a blister in ten minutes.