Outlines of mineralogy and geology ... / [William Phillips].

  • Phillips, William, 1775-1828
Date:
1816
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of mineralogy and geology ... / [William Phillips]. Source: Wellcome Collection.

    45/266 (page 21)
    Those iftinerals commonly called limestones^ and chalk, and marble, are also carbonates of lime. The uses to which lime is applied, (when the carbonic acid with which it is combined, as forming chalk and limestone, is driven oif by heat) are well known. The rocks on each side the Avon near Bristol, are of a peculiar kind of limestone, which has obtained the name of swine-stone, from its yielding when rubbed a fetid smell. This smell was heretofore attributed to the presence of bitumen, but is now be- lieved to be owing to sulphuretted hydrogen. Car- bonate of lime is so abundant, that it is estimated to form one-eighth part of the whole crust of the globe. Lime in combination with the sulphuric acid^ is called sulphate of lime^ or familiarly g^psum,^ Of this mineral the uses are very extensive. When compact, it is called alabaster^ and is employed by the architect for columns and other ornaments, being more easily worked than marble; it is also turned by the lathe into cups, basins, vases, and other similar articles. When sulphate of lime or gypsum, is subjected to a certain heat, it loses what is termed its water of crystallization, and is converted into a fine powder called plaster of paris; the uses of which, when beaten up with water into a paste, for taking ca&ts of gems and statues, are well known. Lime combined with the arsenic acid^ forms a mine- ral called Pharmacolite the only specieswith the * Gyfisum is composed of about 32 parts of lime, 46 of sulphu- ric acid, and 21 of water. f The Pharmacolite is composed of about 46 parts of arsenic acid, 23 of lime, 6 of silex, 22 of water, and a small portion of oxide of cobalt.