Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.
SAL AMMONIAC ,' or AMMONIUM CHLORIDE, NH4C1, the earliest known See also:salt of See also:ammonia (q.v.), was formerly much used in See also:dyeing and metallurgic operations. The name Hammoniacus sal occurs in See also:Pliny (Nat. Hist. xxxi. 39), who relates that it was applied to a See also:kind of fossil salt found below the See also:sand, in a See also:district of See also:Cyrenaica. The See also:general See also:opinion is, that the sal ammoniac of the ancients was the same as that of the moderns; but the imperfect description of Pliny is far from being conclusive. The native sal ammoniac of Bucharia, described by See also:Model and See also:Karsten, and analysed by M. H. See also:Klaproth, has no resemblance to the salt described by Pliny. The same remark applies to the sal ammoniac of volcanoes. Dioscorides (v. 126), in mentioning sal ammoniac, makes use of a phrase quite irreconcilable with the description of Pliny, and rather applicable to See also:rock-salt than to our sal ammoniac. Sal ammoniac, he says, is peculiarly prized if it can be easily split into rectangular fragments. Finally, we have no See also:proof whatever that sal ammoniac occurs at See also:present, either near the See also:temple of See also:Jupiter See also:Ammon, or in any See also:part of Cyrenaica. Hence we conclude that the See also:term sal ammoniac was applied as indefinitely by the ancients as most of their other chemical terms. It may have been given to the same salt which is known to the_ moderns by that appellation, but was not confined to it.
In any See also:case there can be no doubt that it was well known to the alchemists as See also:early as the 13th See also:century. Albertus See also:Magnus, in his See also:treatise De alchymia, informs us that there were two kinds of sal ammoniac, a natural and an artificial. The natural was sometimes See also: In 1716 C. J. See also:Geoffroy read a See also:paper to the See also:French See also:Academy, showing that sal ammoniac must be formed by sublimation; but his opinion was opposed so violently by W. Homberg and N. See also:Lemery, that the paper was not printed. In 1719 D. Lemaire, the French See also:consul at See also:Cairo, sent the Academy an See also:account of the mode of manufacturing sal ammoniac in Egypt. The salt, it appeared, was obtained by See also:simple sublimation from See also:soot. In the year 176o See also:Linnaeus communicated to the Royal Society a correct detail of the whole See also:process, which he had received from Dr F. See also:Hasselquist, who had travelled in that country as a ' Some derive the name sal ammoniac from Jupiter Ammon, near whose temple it is alleged to have been found; others, from a district of Cyrenaica called Ammonia. Pliny's derivation is from the sand (4taµos) in which it occurred.naturalist (Phil. Trans., 176o, p. 504). The dung of See also:black See also:cattle, horses, See also:sheep, goats, &c., which contains sal ammoniac ready formed, is collected during the first four months of the year, when the animals feed on the See also:spring grass, a kind of See also:clover. It is dried, and sold to the See also:common See also:people as See also:fuel. The soot from this fuel is carefully collected and sold to the sal ammoniac makers, who See also:work only during the months of See also: Dr See also:Thomson first pointed out a process by See also:synthesis, which has the See also:advantage of being very simple, and at the same See also:time rigidly accurate, resulting from his observation that when hydrochloric See also:acid See also:gas and ammonia gas are brought in contact with each other, they always combine in equal volumes.
The first See also:attempt to manufacture sal ammoniac in Europe was made, about the beginning of the 18th century, by Mr See also:Goodwin, a chemist of See also:London, who appears to have used the See also:mother ley of common salt and putrid urine as ingredients. The first successful manufacture of sal ammoniac in See also:Great See also:Britain was established in See also:Edinburgh about the year 176o. It was first manufactured in See also:France about the same time by A. See also:Baume. Manufactories of it were afterwards established in See also:Germany, See also: The pure salt has a See also:sharp saline See also:taste and is readily soluble in See also:water. It readily volatilizes, and if moisture be rigorously excluded, it does not dissociate, but in the presence of See also:mere traces of water it dissociates into ammonia and hydrochloric acid (H. B. See also:Baker, Journ. Chem. See also:Soc., 1895, 65, p. 612). Sal ammoniac (ammonium chloride, See also:British and See also:United States pharmacopoeiae) as used in See also:medicine is a white crystalline odourless See also:powder having a saline taste. It is soluble in i in 3 of See also:cold water and in I in 50 of 90 % See also:alcohol. It is incompatible with See also:carbonates of the alkalis. The dose is 5 to 20 grs. Ammonium chloride has a different See also:action and therapeutic use from the See also:rest of the ammonium salts. It possesses only slight See also:influence over the See also:heart and respiration, but it has a specific effect on mucous membranes as the elimination of the See also:drug takes See also:place largely through the lungs, where it See also:aids in loosening bronchial secretions. This action renders it of the utmost value in See also:bronchitis and See also:pneumonia with associated bronchitis. The drug may be given in a mixture with glycerine or See also:liquorice to See also:cover the disagreeable taste or it may be used in a spray by means of an atomizer. The inhalation of the fumes of nascent ammonium chloride by filling the See also:room with the gas has been recommended in foetid bronchitis. Though ammonium chloride has certain irritant properties which may disorder the See also:stomach, yet if its mucous membrane be depressed and atonic the drug may improve its See also:condition, and it has been used with success in gastric and intestinal catarrhs of a subacute type and is given in doses of to grains See also:half an See also:hour before meals in painful See also:dyspepsia due to hyperacidity. It is also an intestinal and hepatic stimulant and a feeble diuretic and diaphoretic, and has been considered a specific in some forms of See also:neuralgia. Additional information and CommentsThere are no comments yet for this article.
» Add information or comments to this article.
Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML. Site content, images, and layout Copyright © 2006 - Net Industries, worldwide. |
|
[back] SAKI |
[next] SALA, GEORGE AUGUSTUS HENRY (1828-1895) |