Sir James Hall's experiments have completely demonstrated the contrary of what is here asserted: they have added much to the evidence of the Huttonian system; and, independently of all theory, have narrowed the circle of prejudice and error.
Note xv. § 83.
On Granite.
1. Granite Veins.
272. It is said above, [§ 77], that granite is found in unstratified masses, and in veins. In the former of these conditions, it constitutes entire mountains, and forms the central ridge of many of the greatest chains that traverse the surface of the earth. It is the granite of this kind that has been most generally described by travellers and mineralogists. The veins have not been so much attended to, though they are of peculiar importance for ascertaining the relation between granite and other fossils.
273. Though Dr Hutton was the first geologist who explained the nature of granite veins, and who observed with attention the phenomena which accompany them, he is not the first who has mentioned them. M. Besson found veins of this kind in the Limoges, in an argillaceous schistus, and unconnected, as far as appeared, with any large mass of granite.[139]
[139] Journal de Phys. tom. xxix. p. 89.
Saussure met with granite veins in the Valorsine, but did not see them distinctly. He ascribed them to infiltration.[140] The date of this observation is in 1776: He afterwards discovered similar appearances at Lyons.[141]
[140] Voyage au Alpes, tom. i. § 598, 599.
[141] Ibid. § 601.