The Wrist, or Joncture of the Hand and Arm, becomes smaller when the Hand is shut, and enlarges it self as the Hand is opened; but the Arm, on all sides, between the Elbow and the Shoulder, has a quite contrary effect; the Reason is this; that whereas in opening the Hand, the Muscles which contribute thereto, being stretch'd out and extended, do render the Arm more slender between the Elbow and the Hand; in clenching it, these same Muscles being swell'd and enlarged, start off from the Bone, and by that means thicken and dilate the same part of the Arm.