The elements of experimental chemistry (Volume 2).

  • Henry, William, 1774-1836.
Date:
1819
Catalogue details

Licence: Public Domain Mark

Credit: The elements of experimental chemistry (Volume 2). Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

    12/472
    PHOSPHATES. CHAP. X\ . SECTION III. Phosphates. With alkaline and earthy bases, the phosphoric acid composes a class of salts called Phosphates, which have the following gene- ric characters. 1. When heated with charcoal, they are not decomposed, nor is phosphorus obtained. 2. They melt, before the blow-pipe, into a hard globule, some- times transparent, at others opaque. 3. The earthy phosphates are soluble in nitric, muriatic, and ace- tic acids, without eflfervescence, and are precipitated from those acids by lime-water and by pure ammonia. 4. They are decomposed, in part, by sulphuric acid, and yield a liquor which, on evaporation and distillation with charcoal, affords phosphorus. The most important combinations of phosphoric acid are those which it forms with soda, ammonia, barytes, and lime. 1. Phosphate of Soda, obtained by saturating carbonate of soda with phosphoric acid, and evaporating the solution, exists in crys- tals, which have always an excess of alkali. These crystals con- tain 62 per cent, of water, and when calcined by a red heat arc converted into a white powder, which consists of Phosphoric acid .... 53.48 ... 100 Soda 46.52 ... 87 100. Hence the crystals are composed of Phosphoric acid .... 20.33 Soda 17.67 Water 62. 100. 2. Phosphate of Ammonia exists with at least three different proportions of its elements. The neutral phosphate forms regular crystals, which are very soluble. By adding to this either an ex- cess of acid or of base, we obtain distinct salts, which require far- ther investigation. 3. Phosphate of Barytes varies, also, in the proportion of its ele- ments. (a) The neutral phosphate may be obtained by mixing the solu- tions of muriate of barytes and phosphate of soda. It consists of