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.

    15/768 (page 3)
    succeeded in effecting the decomposition of the alkalis by galvanic action, and obtained from them oxygen and bases having metallic properties. He submitted the earths to the same powerful instrument of analysis; and though their decomposition was less perfect, it was suffi- ciently so to demonstrate that they also consist of metal- lic bases in an oxidated state. And thus, the whole series of substances capable of neutralizing acids, and so strict- ly connected in other general properties, were, with the exception of ammonia, proved to be composed of metals combined with an oxygen ; and an uninterrupted grada- tion was established from the alkalis to the earths, and from them to the metallic oxides. Though the alkalis, earths, and metallic oxides have been connected by these discoveries, there remain suffi- cient reasons to arrange them as distinct orders. The bases of the alkalis and the earths, admitting them to be metallic, possess marked distinctions from the common metals, both in physical and chemical properties; and ex- cept in the leading character of combining with the acids, the alkalis are very different in their qualities from the metallic oxides, and are much more active in their che- mical relations. The earths approach nearer to the me- tallic oxides, and form the link connecting them with the alkalis. In this series, then, of alkalis, earths, and me- tallic oxides, the history of these substances will be gi- ven *. * As this arrangement is somewhat different from that com- monly followed, in which the earths and greater number of the alkalis are included among the metallic oxides, it may be proper to make some remarks on the advantages which Dr Murray’s method possesses. The principle of his arrangement, it has been already stated, is to class bodies into certain general orders, as Atmospheric Air, Water, Acids, Alkalis, Earths, &c. the characters of which a 2