Ammonia Muri-ata; called also cyreniacus sal, ammoniac salt and armoniac, but improperly; likewise alem-zadar, alemzadad, adarige, aquila, alfol, alacab, alaza-let, alcob, alfatide, aliocab, alisteles, almisadar, anota-sitr, hasacium, musadi.

Many writers speak of the natural and artificial. The natural sort, spoken of by the ancients, according to Dioscorides, is only the sal gem, and is reckoned by them among the alimentary salts; but others say-that it was made from the urine of camels, and was deposited in the sands near the temple of Jupiter Ammon. We have no evidence of native sal ammoniac of this sort being found. Tournefort observes, that out of the simple native salts other compounded salts are naturally-produced, viz. the essential salts, which naturally are concreted from the juices of plants, among which are native ammoniacal salts.

The artificial is the only sort known and used in the shops. It is a neutral, composed of a volatile alkaline salt and the acid of sea-salt; hence the term ammonia muriata.

Sal ammoniac is brought to us generally in round cakes, convex on one side, and concave on the other, from the shape of the vessels into which they are sublimed. When these cakes are broken, the salt appears of a needled texture, or composed of striae, running transversely and parallel to one another: the internal part is generally pure, and of an almost transparent whiteness; the outside, for the most part, is foul, and of a yellowish green or black hue.

In England, this salt is obtained from burnt cows' dung; it is obtainable from every species of soot by sublimation or solution. At Newcastle, it is made from the bittern, which remains after making common salt, and old urine; from one hundred pound weight of the bitter cathartic, salt, and three hogsheads of urine, fifty-six pounds of sal ammoniac are obtained. In Egypt it is made from the burnt dung of quadrupeds that feed exclusively on vegetables. This dung is collected only in the first four months in the year, when the cattle feed on spring grass, which is a sort of clover: at other seasons, and when the cattle eat other sort of food, it is unfit for this purpose. As to the camel, its excrements are not preferable to those of any other cattle which feed on grass, nor is their urine ever used. Mr. Hasselquist says, that the salt-workers in Egypt pretend, that the excrements from men, goats, and sheep, are preferable to all others; and he further tells us, that March and April are the only times in which they make this salt. See the account in his voyages.

It may also be produced from

Consequently the tine, ferri muriati, and the hydrar-gyrus muriatus, will be decomposed by either of the preparations in the second column.

The ammoniac salt is soluble in water and in spirit of wine, and in the air alone. It renders water extremely cold during solution; and when dissolved and mixed with a vitriolic acid effervesces violently, producing a sense of cold. Its crystals resemble feathers, or long shining spicula.

Mixed with a fixed alkaline salt, and then sublimed, it affords a dry volatile salt; but mixed with quicklime, its volatile parts are only to be obtained in a liquid form. When unmixed, it may be sublimed with a considerable degree of heat, without the least change in its nature or properties; but if the fire is hastily raised during its sublimation, it volatilises many kinds of bodies mixed with it.

On account of its sea-salt, it turns diluted nitrous acid into aqua regia, but does not curdle milk, nor alter the colour of an infusion of roses.

Rubbed with quick-lime, or with a fixed alkaline salt, it emits an urinous smell, though dry. If a little hydrarg.mur. be added to its solution in lime water, the mixture becomes of a yellow colour.

In soldering, tinning, and casting shot, the crude salt is much used. It becomes volatile in a heat somewhat greater than that of boiling water.

Boerhaave says, thatitpreserves all animal substances from putrefaction; that its brine penetrates deeply; that it is one of the most efficacious, aperient, attenuant, and resolvent medicines, a good sternutatory, diaphoretic, sudorific, and diuretic.

When used externally as a discutient, or detersive, it is mixed with some proper fomentation, in the proportion of 3 vi. or i to ij. of the liquid.

It is more pungent to the taste than common salt, but is less antiseptic; it is a more powerful sudorific, and a less active purgative. In large doses, as 3ij- it opens the belly, and in yet larger it proves emetic; it is a good febrifuge, and peculiarly assistant to the bark. In many instances, where the bark and emetics failed in agues, the crude salt given to Э i. every four hours, with an infusion of camomile flowers, for some days, then every six, and at least every eight hours. hath succeeded: it is used both as an antiseptic and a repellent in gargles; when the throat is inflamed, it powerfully dissolves viscid mucus in the mouth and fauces. In violent hypochondriac cases it hath been of singular efficacy, by a daily use of it in doses just within what are required to render the bowels lax, or perhaps in such as produce a slight looseness; after taking it six, eight, and twelve months, the cold bath hath completed the cure. From 3 i. to 3 ij- dissolved in viij. of any simple water, is a good substitute for the common saline mixture, and may be given, as to quantity and time, in the same manner. Dr. Cullen, however, doubts of these powers. He does not admit of its attenuating or dissolving the fluids; but, like other saline matters, in passing by the excretories it may be suited to promote their discharge. With the Peruvian bark, it may be of some use as a diaphoretic; but he doubts that in obviating the consequences apprehended from the use of the bark it can be of any service: nor does he allow that, externally applied, it has the power of discussing tumours, otherwise than by giving a moderate stimulus to the vessels on the surface; not by entering the pores, and by that means attenuating the viscid fluids. Materia Medica, vol. ii.

Truth, as usual, perhaps lies between. Like otherneu-trals, it seems to assist the febrifuge power of the bark, and prevent the latter producing the stricture on the surface, which sometimes occasions great inconvenience. Yet we have not been aware that it is more useful than any other neutral. It does not act as a laxative, but in a dose that is not agreeable to the stomach, and that few will persist in. As a gargle and a discutient, however, it may act; we have found it highly useful. Mr. Jus-tamond strongly recommends the following in the cure of the milk abscess. . Ammoniae muriatae i. sps. ro-ris marini i. m. Linen rags should bed ipped into this, and kept continually moist on the part affected. Ammoniae muriatae ss. aceti. sps. vinosi rectificati, āā Њ i. m. is also an useful application.

The impurities of this salt will not dissolve in common water; and the purification is consequently effected by the solution and filtration. The very last crystals seldom betray any mixture of any other salt.

Preparations of this drug are the ammonia prepared.

Flos salis ammoniaci, which is only the salt sublimed; and hath been called aquila alba philosophorum, and aquila Ganymedis.

Ammoniaci vegetabilis, Sal. See Sp. Mindereri, under Alcali.