70. Whinstone of every species is found frequently interposed in tabular masses, between beds of stratified rocks; and it then adds to the indications of its igneous origin, already enumerated, some others that are peculiar to it when in this situation. In such instances, it is not uncommon to find the strata in some places, contiguous to the whin, elevated, and bent with their concavity upward, so that they appear clearly to have been acted on by a force that proceeded from below, at the same time that they were softened, and rendered in some degree flexible: it is needless to remark, that these effects can be explained by nothing but the fusion of the whin; and that the great force with which it was impelled against the strata, could be produced by no cause but heat, acting in the manner that is here supposed. 71. Again, if it be true that the masses of whin, thus interposed among the strata, were introduced there, after the formation of the latter, we might expect to find, at least in many instances, that the beds on which the whinstone rests, and those by which it is covered, are exactly alike. If these beds were once contiguous, and have been only heaved up and separated by the irruption of a fluid mass of subterraneous lava, their identity should still be recognised. Now, this is precisely what is observed; it is known to hold in a vast number of instances, and is strikingly exemplified in the rock of _Salisbury Crag_, near Edinburgh. This similarity of the strata that cover the masses of whinstone, to those that serve as the base on which they rest, and again the dissimilitude of both to the interposed mass, are facts which I think can hardly receive any explanation, on the principles of the Neptunian theory. If these rocks, both stratified and unstratified, are to be regarded as productions of the sea, the circumstances would require to be pointed out, which have determined the whinstone, and the beds that are all round it, to be so extremely unlike in their structure, though formed at the same time, and in the immediate vicinity of one another; as also those circumstances, on the other hand, which determined the stratified deposits above and below the whinstone, to be precisely the same, though the times of their formation must have been very different. The homogeneous substances, thus, placed at a distance, and the heterogeneous brought so closely together, are phenomena equally unaccountable, in a theory that ascribes their origin to the operation of the same element, and that necessarily dates their formation according to the order in which they lie, one above another.