The Chevalier de Dolomieu, in describing
the volcanic productions of Etna, mentions a lava which had flowed from
that mountain, and which may be considered as a granite. But M. de
Saussure has put this matter out of doubt by describing most accurately
what he had seen both in the Alps and at the city of Lyons. These are
veins of granite which have flowed from the contiguous mass into the
stratified stone, and leave no doubt with regard to this proposition,
that the granite had flowed in form of subterranean lava, although M. de
Saussure has drawn a very different conclusion from this appearance. I
have also a specimen from this country of a vein of granite in a granite
stone, the vein being of a smaller grain than that of the rock which it
traverses.[20]
[Note 20: This is what I had wrote upon, the subject of granite, before
I had acquired such ample testimony from my own observations upon
that species of rock. I have given some notice, in the 3d vol. of the
Transactions of the Edinburgh R.S. concerning the general result of
those observations, which will be given particularly in the course of
this work.
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