Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/101

 Rh had not exhibited to me any sensible difference with respect to its specific gravity, whether this was taken whilst this substance had experienced only a very slight change, or whether when it was much more considerably altered. This fact which I did not expect, attributing, according to the opinion generally entertained, its disintegration or efflorescence to the loss of its water either of composition and consequently combined with it, or of crystallisation, and in that case simply interposed between its particles, this fact, I say, greatly surprised me. But is it true that in the laumonite, as well as in all the salts which effloresce on exposure to the atmosphere, this phenomenon is to be attributed to the loss of water? as far as the laumonite is concerned it appears to me very probable that this destruction is in reality, as I have said, nothing more than the simple result of disintegration. That this is the case will appear from the changes which occur in this mineral, and principally from the greater or less regularity of the primitive form which many of the smallest fragments preserve, when this alteration has even arrived at such a point that the substance divides of itself. If it is to be attributed to the loss of its water, this can only be the case with respect to that of crystallisation or of simple interposition. But if so, ought not this substance, as happens with regard to hydrophanous bodies, at some period during the loss of its water to have, in consequence of the same affinity which placed it there originally, a great tendency to resume it, and thereby, re-establishing the refractive power which belongs to it in its unaltered state, to recover its transparency, which it never does ? may not its alteration rather be occasioned by a strong attraction of its integrand molecules for caloric, and by the separation produced between them from the introduction of this fluid in larger quantity? I do not mean this as an assertion, but propose it simply as a question.