We took occasion some years ago, in a paper in Maga, to notice the practice, according to this principle of nature, followed by perhaps as great a master of composition (of lines) as any that art has produced--Gaspar Poussin; and we exemplified the rule by reference to some of his pictures; and we remarked that, by this his practice, he made more available for variety and uniformity the space of his canvass. We have since, with much attention, noticed the lines of nature, when most beautiful,--have watched the clouds, how they have arched valleys, and promoted a correspondence of sentiment,--and how, in woods, the receding and approaching lines of circles have made the meetings and the hollows, which both make space, and are agreeable. We are not setting forth _our_ line of beauty. We would rather suggest that it is possible the idea of the wave or curve, right in itself, may be carried to a still greater completeness. It may, in fact, only be a part of beauty, which must scarcely be limited to a single line, or rather figure. We should have hesitated, lest we should seem to have hazarded a crude theory, if it had appeared to be entirely in opposition to Mr Eastlake. We think, upon the whole view, it rather advances his, and reconciles it as a part only with that of Burke and Hogarth. The thing stated may be true, when the reason given for it may be untrue, or at least insufficient. The notion of life and its antagonism is true; but its application may be more ingenious, and in the nature of a similitude, than an absolute foundation; for many similar referable correspondences of ideas may be given, as the range of similitude is large. But the objection to them is that they are mental, and will not, therefore, apply unconditionally in a theory from which we set out by abstracting association. Nor can we go so far as to carry this idea of "life" into the theory of colour. "Colour," says Mr Eastlake, "viewed under the ordinary effects of light and atmosphere, may be considered according to the same general principles. It is first to be observed that, like forms, they may or may not be characteristic, and that no object would be improved by means, however intrinsically agreeable, which are never its own. Next, as to the idea of life: creatures exhibit the hues with which nature has clothed them in greatest brilliancy during the period of consummate life and health. Bright red, which, by universal consent, represents the idea of life, (perhaps from its identity with the hue of the blood,) is the colour which most stimulates the organs of sight."