Fig. [64 B p. II] is meant to represent the manner, in which most of the muscles, (those of the limbs in particular) are twisted round the bones, and conform themselves to their length and shape; but with no anatomical exactness. As to the running of their fibres, some anatomists have compared them to skains of thread, loose in the middle, and tight at each end, which, when they are thus consider'd as twisted contrary ways round the bone, gives the strongest idea possible of a composition of serpentine-lines.
Of these fine winding forms then are the muscles and bones composed, and which, by their varied situations with each other, become more intricately pleasing, and form a continued waving of winding forms from one into the other, as may be best seen by examining a good anatomical figure, part of which you have here represented, in the muscular leg and thigh, fig. [65 p. I]: which shews the serpentine forms and varied situations of the muscles, as they appear when the skin is taken off. It was drawn from a plaster of paris figure cast off nature, the original of which was prepared for the mould by Cowper, the famous anatomist. In this last figure, as the skin is taken off the parts are too distinctly traced by the eye, for that intricate delicacy which is necessary to the utmost beauty; yet the winding figures of the muscles, with the variety of their situations, must always be allow'd elegant forms: however, they lose in the imagination some of the beauty, which they really have, by the idea of their being flayed; nevertheless, by what has already been shewn both of them and the bones, the human frame hath more of its parts composed of serpentine-lines than any other object in nature; which is a proof both of its superior beauty to all others, and, at the same time, that its beauty proceeds from those lines: for although they may be required sometimes to be bulging in their twists, as in the thick swelling muscles of the Hercules, yet elegance and greatness of taste is still preserved; but when these lines lose so much of their twists as to become almost straight, all elegance of taste vanishes.
Thus fig. [66 p. I], was also taken from nature, and drawn in the same position, but treated in a more dry, stiff, and what the painters call, sticky manner, than the nature of flesh is ever capable of appearing in, unless when its moisture is dryed away: it must be allowed, that the parts of this figure are of as right dimensions, and as truly situated, as in the former; it wants only the true twist of the lines to give it taste.
To prove this further, and to put the mean effect of these plain or unvaried lines in a stronger light, see fig. [67 p. I], where, by the uniform, unvaried shapes and situation of the muscles, without so much as a waving-line in them, it becomes so wooden a form, that he that can fashion the leg of a joint-stool may carve this figure as well as the best sculptor. In the same manner, divest one of the best antique statues of all its serpentine winding parts, and it becomes from an exquisite piece of art, a figure of such ordinary lines and unvaried contents, that a common stone-mason or carpenter, with the help of his rule, calipers, and compasses, might carve out an exact imitation of it: and were it not for these lines a turner, in his lathe, might turn a much finer neck than that of the grecian Venus, as according to the common notion of a beautiful neck, it would be more truly round. For the same reason, legs much swoln with disease, are as easy to imitate as a post, having lost their drawing, as the painters call it; that is, having their serpentine-lines all effaced, by the skin's being equally puffed up, as figure [68].
If in comparing these three figures one with another, the reader, notwithstanding the prejudice his imagination may have conceiv'd against them, as anatomical figures, has been enabled only to perceive that one of them is not so disagreeable as the others; he will easily be led to see further, that this tendency to beauty in one, is not owing to any greater degree of exactness in the proportions of its parts, but merely to the more pleasing turns, and intertwistings of the lines, which compose its external form; for in all the three figures the same proportions have been observ'd, and, on that account, they have all an equal claim to beauty.
And if he pursues this anatomical enquiry but a very little further, just to form a true idea of the elegant use that is made of the skin and fat beneath it, to conceal from the eye all that is hard and disagreeable, and at the same time to preserve to it whatever is necessary in the shapes of the parts beneath, to give grace and beauty to the whole limb: he will find himself insensibly led into the principles of that grace and beauty which is to be found in well-turn'd limbs, in fine, elegant, healthy life, or in those of the best antique statues; as well as into the reason why his eye has so often unknowingly been pleased and delighted with them.