First meeting of the British Association for the Advancement of Science / [Jas. F.W. Johnston].

  • James Finlay Weir Johnston
Date:
[1832]
Catalogue details

Licence: Public Domain Mark

Credit: First meeting of the British Association for the Advancement of Science / [Jas. F.W. Johnston]. Source: Wellcome Collection.

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    ed by volcanoes, then active, and pouring out their lavas over the whole surface of the earth ; and that the now overlying bed had been deposited on the surface of these lavas since the vol¬ canoes became extinct. Mr Murchison bore testimony to the ability of the paper, while he differed from the author in his conclusions. From the observations he had himself made upon the whin-sill, and from the apparent connection of the whin-dikes of Durham, the great Bolam dikes in particular, with the stratified basalt in question, he had no doubt that it had been injected lateral¬ ly, and at a late date, not only into the carboniferous limestone series but into later rocks. At the same time the matter was still open to inquiry, and he considered it particularly desi¬ rable to trace whether the branches thrown off by the Bolam dike, and all bearing towards the whin-sill, had actually any connection with it. Mr Phillips very plausibly argued that both parties might be in the right. He considered it probable that the sill had been ejected by an active volcano during the deposition of the metalliferous limestone, and was thus anterior to some beds, and posterior to others,—a position which he supported with his accustomed ingenuity. The fourth paper was upon Vanadium, in which a short ac¬ count of the discovery of the metal by Del Rio, by Sefstrom, and by myself were given, and the mineral from which it is ob¬ tained, and several preparations and salts of the new metal were exhibited. The substance of this paper is inserted in the pre¬ ceding number of this Journal. I was enabled to exhibit some exceedingly beautiful crystals of Vanadic acid formed by gra¬ dual cooling. They are in long flat prisms, reddish brown, with a shade of purple, transparent, of a high degree of lustre, pos¬ sessing a refractive power nearly equal to that of the diamond, have regular double refraction, and belong to the prismatic system of Mohs. The next paper was an able and interesting sketch of the ancient Flora by Mr Witham of Lartington. The results of his researches into the structure of fossil vegetables, and the light they throw on the character of the vegetation of former ages, were clearly and eloquently stated ; and all remained satis- B
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