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.

    31/768 (page 19)
    water at the temperature of 60° ; it crystallizes in prisms. By exposure to heat, it is fused into a transparent glass, and decomposed, part of its ammonia being expelled. Heated with charcoal, its acid suffers decomposition, its oxygen being abstracted, which is not the case with the other phosphates. Like phosphate of soda, it may be used with advantage in analyses by the blowpipe. Phos- phate of soda and ammonia, formerly called Microcosmic salt, is a triple salt of definite composition, consisting of one atom of phosphate of soda, 60, one of phosphate of ammonia, 45, and no less than 16 atoms of water when crystallized ; its equivalent is hence 250. It is crystal- lizable, abundantly soluble in water, and very fusible. Phosphite of Ammonia has a strong penetrating taste ; crystallizes in minute spiculae. Exposed to the blowpipe it is decomposed, with the disengagement of phosphuret- ted hydrogen. Hypophosphite of Ammonia is very so- luble in water and in alcohol. Borate of Ammonia is obtained by evaporation of its solution in prismatic crys- tals, of a sharp taste, and which change the vegetable co- lours to a green. Muriate of Ammonia.—This is the sal-ammoniac of commerce, an important salt from the uses to which it is applied ; it is generally prepared on a large scale by in- direct processes. A manufacture of it has been carried on in Egypt from time immemorial. It is there procu- red chiefly by sublimation from the soot of camels’ dung. Large quantities of it have been prepared in Europe for a number of years past, so that the Egyptian sal-ammo- niac is no longer imported. The processes followed in this country are various, but, in general, the first step is to procure a sulphate of ammonia, either by macerating soot, (which contains that salt in water,) or by directly combining sulphuric acid with impure ammonia, obtained B 2