No CrossRef data available.
Published online by Cambridge University Press: 01 May 2009
It is a pretty well recognized fact that Obsidian is a hydrous silicate of indefinite composition and your fusion experiments confirm that fact. Now molten obsidian may give off its H2O in consequence of two processes—by simple vesiculation, or by the individualization from the glass of a definite anhydrous silicate. More commonly these two processes have gone on together, but modified by the vicissitudes of temperature that the molten aquiferous glass is exposed to during its eruption.
Prof. G. A. T. Cole and Mr. G. W. Butler, the authors of a recent paper “On the Lithophyses in the Obsidian of the Rocche Rosse, Lipari” (Q. J. G. S. August, 1892), having found that Dr. Johnston-Lavis had been led to an interpretation of the facts considered, different from theirs, and hitherto unpublished, asked him to add to the discussion of the matter a brief abstract of his views. In accordance with his suggestion, his reply is here published.—Edit. Geol. Mag.
1 Prof. G. A. T. Cole and Mr. G. W. Butler, the authors of a recent paper “On the Lithophyses in the Obsidian of the Rocche Rosse, Lipari” (Q. J. G. S. August, 1892), having found that Dr. Johnston-Lavis had been led to an interpretation of the facts considered, different from theirs, and hitherto unpublished, asked him to add to the discussion of the matter a brief abstract of his views. In accordance with his suggestion, his reply is here published.—Edit. Geol. Mag.