278. The granite veins in Glentilt, where Dr Hutton made his first observations on this subject, are not, I believe, visibly connected with any large mass of the same rock.[142] The bed of the river Tilt, in the distance of little more than a mile, is intersected by no less than six very powerful veins of granite, all of them accompanied with such marks of disorder and confusion in the strata, as indicate very strongly the violence with which the granite was here introduced into its place. These veins very probably belong to the great mass of granite which is known to form the central ridge of the Grampians further to the north; but they are several miles distant from it, and the connection is perhaps invisible in the present state of the earth's surface. [Footnote 142: Trans. Royal Society Edin. Vol iii. p. 77, &c.] 279. The second kind of granite vein, is one which proceeds visibly from a mass of that rock, and penetrates into the contiguous strata. The importance of this class of veins, for ascertaining the relation between granite and other mineral bodies, has been pointed out, § 82; and by means of them it has been shown, that the granite, though inferior in position, is of more recent formation than the schistus incumbent on it; and that the latter, instead of having been quietly deposited on the former, has been, long after its deposition and consolidation, heaved up from its horizontal position, by the liquid body of granite forcibly impelled against it from below. It has been alleged, in order to take off the force of the argument derived from granite veins, that these veins are formed by infiltration, though, to give any probability to this supposition, it would be necessary to show, that water is able to dissolve the ingredients of granite; and even if this could be done, the direction which the veins have, in many instances, rising up from the granite, is a proof, as remarked § 82, that they cannot be the effect of infiltration. Another objection has been thrown out, namely, that the veins here referred to are not of true granite, according to the definition which mineralogists have given of that substance. The force of a fact, however, is not to be lessened by a change of names, or the use of arbitrary definitions. The general fact is, that the granitic mass, and the vein proceeding from it, constitute one continuous, and uninterrupted body, without any line of separation between them. The geological argument turns on this circumstance alone; and it is no matter whether the rock be a syenite, a granitelle, or a real granite. The phenomenon speaks the same language, and leads to the same conclusion, whatever be the technical terms the mineralogist employs in describing it.