careful finish of the work, this may serve for example, that one of the capitals of the Doge's palace is formed of eight heads of different animals, of which one is a bear's with a honeycomb in the mouth, whose carved _cells_ are _hexagonal_. Sec. 16. Abstraction necessary from imperfection of materials. Sec. 17. Abstractions of things capable of varied accident are not imaginative. Sec. 18. Yet sometimes valuable. So far, then, of the abstraction proper to architecture, and to symbolical uses, of which I shall have occasion to speak hereafter at length, referring to it only at present as one of the operations of imagination contemplative; other abstractions there are which are necessarily consequent on the imperfection of materials, as of the hair in sculpture, which is necessarily treated in masses that are in no sort imitative, but only stand for hair, and have the grace, flow, and feeling of it without the texture or division, and other abstractions there are in which the form of one thing is fancifully indicated in the matter of another; as in phantoms and cloud shapes, the use of which, in mighty hands, is often most impressive, as in the cloudy charioted Apollo of Nicolo Poussin in our own gallery, which the reader may oppose to the substantial Apollo, in Wilson's Niobe, and again the phantom vignette of Turner already noticed; only such operations of the imagination are to be held of lower kind and dangerous consequence, if frequently trusted in, for those painters only have the right imaginative power who can set the supernatural form before us fleshed and boned like ourselves.[73] Other abstractions occur, frequently, of things which have much accidental variety of form, as of waves, on Greek sculptures in successive volutes, and of clouds often in supporting volumes in the sacred pictures; but these I do not look upon as results of imagination at all, but mere signs and letters; and whenever a very highly imaginative mind touches them, it always realizes as far as may be. Even Titian is content to use at the top of his St. Pietro Martiri, the conventional, round, opaque cloud, which cuts his trees open like a gouge; but Tintoret, in his picture of the Golden Calf, though compelled to represent the Sinai under conventional form, in order that the receiving of the tables might be seen at the top of it, yet so soon as it is possible to give more truth, he is ready with it; he takes a grand fold of horizontal cloud straight from the flanks of the Alps, and shows the forests of the mountains through its misty volume, like sea-weed through deep sea.[74] Nevertheless, when the realization is impossible, bold symbolism is of the highest value, and in religious art, as we shall presently see, even necessary, as of the rays of light in the Titian woodcut of St. Francis before noticed; and sometimes the attention is directed by some such strange form to the meaning of the