Elements of chemistry, in two volumes / by John Murray.

  • Murray, John.
Date:
1828
Catalogue details

Licence: Public Domain Mark

Credit: Elements of chemistry, in two volumes / by John Murray. Source: Wellcome Collection.

    32/768 (page 20)
    by distilling animal substances. When the sulphate of ammonia is prepared, it is mixed with muriate of soda, and heat applied. The sulphuric acid unites with the soda, and the muriatic acid with the ammonia, forming muriate of ammonia, which, from its volatility, is sublimed. This decomposition is sometimes effected in the humid way, by boiling solutions of the salts, crystallizing the sulphate of soda, and obtaining the sal-ammoniac by evaporation to dryness : sometimes muriatic acid is disengaged from salt by sulphuric acid, and directly combined with impure ammonia. From the manner of its preparation by sub- limation in globular vessels, sal-ammoniac is obtained in large semi-spherical cakes of a crystalline structure. By solution in boiling water and cooling it may be crystal- lized, its crystals being four-sided prisms. It is soluble in 3± parts of water at 60°, and in its own weight of boil- ing water. It is not deliquescent when pure, or at least only slightly so in a humid atmosphere : it is easily vola- tilized by heat. It is used in several of the arts, as in sol- dering metals, to clean their surfaces which are to be uni- ted, and to prevent oxidation: in dyeing, it renders se- veral colours brighter; and it is from this salt that ammo- nia is usually procured. Its composition is easily shown by direct formation; and it will be found that equal vo- lumes of muriatic acid and ammoniacal gases combine to produce it; or it consists of one atom of acid, 37, and one of ammonia, 17 ; its equivalent is therefore 54 *. Chlorate of Ammonia is formed by decomposing carbonate of ammonia by chlorate of lime : it crystallizes in needles; is very soluble in water and in alcohol, and is easily decomposed by heat. * On the old theory of the nature of muriatic acid, this salt contains 16.7 parts in the hundred of water derived from the acid.