Volume 2

The elements of experimental chemistry / by William Henry.

  • Henry, William, 1774-1836.
Date:
1815
Catalogue details

Licence: Public Domain Mark

Credit: The elements of experimental chemistry / by William Henry. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    4> States that 100 grains of phosphorus condense 450 cubic inches or 15'i grains of oxygen gas. The product, when the gas is more than sufficient for the combustion of the phosphorus, is entirely phosphoric acid. (c) By the nitric acid. If phosphorus be cautiously added, by a little at once, to nitric acid, heated in a re- tort, the nitric acid is decomposed, and its oxygen, uniting with the phosphorus, constitutes phosphoric acid. A tubu- lated retort must be used for this purpose; and its neck may terminate in the apparatus already described for pro- curing nitric acid. By this contrivance a considerable quantity of nitric acid will be saved. SECTION II, Phosphoric Acid. I. To prepare this acid, the process h or c, sect. 1. may be employed; but the following is the most economical method. On 20 pounds of bone, calcined to whiteness and finely powdered, pour 20 quarts of boiling water, and add eight pounds of sulphuric acid, diluted with an equal weight of water. Let these materials be well stirred toffether, and be kept in mixture about 24 hours. Let the whole mass be next put into a conical bag of sufficiently porous and strong linen, in order to separate the clear liquor, and let it be washed with water, till the water ceases to have much acidity to the taste. Evaporate the strained liquor in earthen vessels, placed in a sand-heat, and, when reduced to about half its bulk, let it cool. A white sediment will form in considerable quantity, which must be allowed to subside; the clear solution must be decanted, and boiled to dryness in a glass vessel. A white mass will remain, which is the dry phosphoric acid. This may be fused in a crucible, and poured out in a clean copper di^h. A trans-