The surface of a piece of ornament, that hath every turn in it that lines are capable of moving into, and at the same time no way applied, nor of any manner of use, but merely to entertain the eye, would be such an object as would answer to this first idea alone. The figure like a leaf, at the bottom of plate I, near to fig. 67, is something of this kind; it was taken from an ash-tree, and was a sort of Lusus naturæ, growing only like an excressence, but so beautiful in the lines of its shell-like windings, as would have been above the power of a Gibbons to have equalled, even in its own materials; nor could the graver of an Edlinck, or Drevet, have done it justice on copper. [Illustration: Fig. near Fig. 67] Note, the present taste of ornaments seems to have been partly taken from productions of this sort, which are to be found about autumn among plants, particularly asparagus, when it is running to seed. I shall now endeavour to explain what is included in what I have called for distinction sake, the second _general idea_ of form, in a much fuller manner than was done in Chapter I, of Fitness. And begin with observing, that though surfaces will unavoidably be still included, yet we must no longer confine ourselves to the particular notice of them as surfaces only, as we heretofore have done; we must now open our view to general, as well as particular bulk and solidity; and also look into what may have filled up, or given rise thereto, such as certain _given_ quantities and dimensions of parts, for inclosing any substance, or for performing of _motion, purchase, stedfastness,_ and other matters of use to living beings, which, I apprehend, at length, will bring us to a tolerable conception of the word _proportion_. As to these _joint-sensations_ of bulk and motion, do we not at first sight almost, even without making trial, seem to _feel_ when a leaver of any kind is too weak, or not long enough to make such or such a purchase? or when a spring is not sufficient? and don't we find by experience what weight, or dimension should be given, or taken away, on this or that account? if so, as the general as well as particular bulks of form, are made up of materials moulded together under mechanical directions, for some known purpose or other; how naturally, from these considerations, shall we fall into a judgment of _fit proportion_; which is one part of beauty to the mind tho' not always so to the eye.