The chemical pocket-book, or memoranda chemica; arranged in a compendium of chemistry ... with Bergman's table of single elective attractions / as improved by Dr. G. Pearson.

  • Parkinson, James, 1755-1824
Date:
1807
Catalogue details

Licence: Public Domain Mark

Credit: The chemical pocket-book, or memoranda chemica; arranged in a compendium of chemistry ... with Bergman's table of single elective attractions / as improved by Dr. G. Pearson. Source: Wellcome Collection.

    26/394 (page 6)
    possess also the characters of alkalies, having a strong taste, and being readily soluble in water, and turning vegetable blues, green. The former we shall consider as Fourths simply, and the latter as alkaline earths. The first of these are five in number. 1. Silica, is the earth which chiefly forms flint, quartz, rock crystal, and many of the gems. It is white, of a rough and harsh feel. Sp. gr. 2,06’. It neither combines with oxygen, the simple combustibles, nor metals; nor is it acted on by nitrogen. The phosphoric and boracic acids unite with it by fusion ; but it is dissolved by no other acid but the fluoric : and yet an alkaline solution of this earth admits of supersaturation with an acid, particularly the muriatic, without any precipita- tion.- When newly precipitated it is soluble in 1000 parts of water. Alone it is infusible, or nearly so ; but fuses readily with flxetl alkalies, which act on it even in the moist way. It com- bines with barytes, strontia, lime, and alumine; and, in most vio- lent heats, w ith magnesia. It also may be fused by being joined with lime and alumine. To obtain this earth pure, it should be precipitated from its alkaline solution by muriatic acid. 2. Alumine, or Earth of Alum, is the true argillaceous part of common clay. When pure it is smooth, and has an unctuous feel. It is tasteless, and has no smell, except when it contains oxide of iron. It is sometimes found native in blue transparent crystals. It is not soluble in router. Sp. gr. 2,00. When heated it diminishes in bulk, and, it is said, may be so hardened by fire as to give sparks with steel. It combines with most acids, though with difficulty, uniting best during precipitation. With the sulphuric it forms alum, but with the nitric and muriatic it crystallizes difficultly. It is not affected by oxygen, or nitrogen, nor does it com- bine with the metals, or the simple combustibles. It is indeed found native in combination with charcoal. It combines with the alkalies, and the alkaline earths. 3. ZirconiA is found in the stone called Jargon, from Ceylon, and in the Hyacinth. It is a white, tasteless, and iuo»