What rocks were the chief components of ancient landscape foreground.

We have now only to observe the close characteristics of the rocks and soils to which the large masses of which we have been speaking owe their ultimate characters.

We have already seen that there exists a marked distinction between those stratified rocks whose beds are amorphous and without subdivision, as many limestones and sandstones, and those which are divided by lines of lamination, as all slates. The last kind of rock is the more frequent in nature, and forms the greater part of all hill scenery. It has, however, been successfully grappled with by few, even of the moderns, except Turner; while there is no single example of any aim at it or thought of it among the ancients, whose foregrounds, as far as it is possible to guess at their intention through their concentrated errors, are chosen from among the tufa and travertin of the lower Apennines (the ugliest as well as the least characteristic rocks of nature), and whose larger features of rock scenery, if we look at them with a predetermination to find in them a resemblance of something, may be pronounced at least liker the mountain limestone than anything else. I shall glance, therefore, at the general characters of these materials first, in order that we may be able to appreciate the fidelity of rock-drawing on which Salvator's reputation has been built.