Copy 1, Volume 1

Outlines of mineralogy, geology, and mineral analysis / By Thomas Thomson.

  • Thomas Thomson
Date:
1836
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of mineralogy, geology, and mineral analysis / By Thomas Thomson. Source: Wellcome Collection.

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    alphabetical catalogue of minerals, to a great number of which he has affixed his own determination of the primary crystal- line form. Mr. William Phillips, in his Elements of Mineralogy, has not only given the primary form of almost every mineral determined by his own measurement, but likewise figures of the most important of the secondary faces, together with tables of the angles which they form with each other, and with the primary faces. ‘This stamps a value upon the work of no ordinary kind. : In Germany, the mathematical theory of crystals was investigated by M. Weiss; and he conceived the fortunate idea of connecting all the secondary forms with the primary form by simple laws. ‘This makes it much easier to remember the whole, by giving a unity to the subject, which Hauy has failed to do. Most of his calculations were made from the previous measurements of Hauy; but Mohs, who was an excellent practical mineralogist, adopted nearly the same idea. He and Mr. Haidinger, who had made himself a profound master of the theory of crystals, examined anew the angles of a vast number of crystallized minerals, and founded upon these labours a system of mineralogy, which they endeavoured to make independent of every other branch of science. ‘They arranged minerals into classes, orders, genera, and species. livery species is distinguished by a property considered as capable of accurately discriminating it from every other species. ‘This property is called the characteristic. It is founded upon three characters of minerals, namely, the hardness, specific gravity, and the crystalline form. Mohs has arranged all minerals in what he calls a natural history order. ‘The object of his arrangement is to enable a beginner to discover the name of any mineral contained in the system by its characters, precisely in the same way as in botany or entomology, any plant, or insect, contained in the system may be discovered by attending to its characters. And M. Mohs considers it as a vast advantage to mineralogy to be thus freed from the trammels of Chemistry, by which it has been hitherto hampered. It would certainly be a boon to mineralogists of no mean value, if a method could be devised to enable a student to discover the name of any mineral contained in the system. But from the very nature of minerals the discovery of such a method is attended with much greater difficulty than in the
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