Sec. 50. I must pause to make one exception to my general statement that this structure had been entirely ignored. The reader was, perhaps, surprised by the importance I attached to the fragment of mountain background by Masaccio, given in Plate +13+ of the third volume. If he looks back to it now, his surprise will be less. It was a complete recognition of the laws of the lines of aqueous sculpture, asserted as Turner's was, in the boldest opposition to the principles of rock drawing of the time. It presents even smoother and broader masses than any which I have shown as types of hill form; but it must be remembered that Masaccio had seen only the softer contours of the Apennine limestone. I have no memorandum by me of the hill lines near Florence; but Plate +47+ shows the development of limestone structure, at a spot which has, I think, the best right to be given as an example of the Italian hills, the head of the valley of Carrara. The white scar on the hill side is the principal quarry; and the peaks above deserve observation, not so much for anything in their forms, as for the singular barrenness which was noted in the fifteenth chapter of the last volume (Sec. 8) as too often occurring in the Apennines. Compare this plate with the previous one. The peak drawn in Plate +46+ rises at least 7500 feet above the sea,--yet is wooded to its top; this Carrara crag not above 5000,[97]--yet it is wholly barren. Sec. 51. Masaccio, however, as we saw, was taken away by death before he could give any one of his thoughts complete expression. Turner was spared to do _his_ work, in this respect at least, completely. It might be thought that, having had such adverse influence to struggle with, he would prevail against it but in part; and, though showing the way to much that was new, retain of necessity some old prejudices, and leave his successors to pursue in purer liberty, and with happier power, the path he had pointed out. But it was not so: he did the work so completely on the ground which he chose to illustrate, that nothing is left for future artists to accomplish in that kind. Some classes of scenery, as often pointed out in the preceding pages, he was unfamiliar with, or held in little affection, and out of that scenery, untouched by him, new motives may be obtained; but of such landscape as his favorite Yorkshire Wolds, and banks of Rhenish and French hill, and rocky mountains of Switzerland, like the St. Gothard, already so long dwelt upon, he has expressed the power in what I believe to be for ever a central and unmatchable way. I do not say this with positiveness, because it is not demonstrable. Turner may be beaten on his own ground--so may Tintoret, so may Shakespeare, Dante, or Homer: but my _belief_ is that all these first-rate men are lonely men; that the particular work they did was by them done for ever in the best way; and that this work done by Turner among the hills, joining the most intense