Chap. LIX.—The Necessity of anatomical Knowledge.
The painter who has obtained a perfect knowledge of the nature of the tendons and muscles, and of those parts which contain the most of them, will know to a certainty, in giving a particular motion to any part of the body, which, and how many of the muscles give rise and contribute to it; which of them, by swelling, occasion their shortening, and which of the cartilages they surround.
He will not imitate those who, in all the different attitudes they adopt, or invent, make use of the same muscles, in the arms, back, or chest, or any other parts.
MOTION AND EQUIPOISE OF FIGURES.
Chap. LX.—Of the Equipoise of a Figure standing still.
The non-existence of motion in any animal resting on its feet, is owing to the equality of weight distributed on each side of the line of gravity.
Chap. LXI.—Motion produced by the Loss of Equilibrium.
Motion is created by the loss of due equipoise, that is, by inequality of weight; for nothing can
