The hand : its mechanism and vital endowments, as evincing design / by Charles Bell.

  • Bell, Charles, Sir, 1774-1842.
Date:
1860
Catalogue details

Licence: Public Domain Mark

Credit: The hand : its mechanism and vital endowments, as evincing design / by Charles Bell. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    of the muscle is conjoined, the two forces, progressively increas- ing, greatly augment the velocity of the descent. The same interchange of power for velocity, which takes place in the arm, adapts a man's hand and fingers to a thousand arts, requiring quick or lively motions. The fingers of a lady playing on the pianoforte, or of the compositor with his types, are instances of the advantage gained by this sacrifice of force for velocity of movement. The spring of the foot and toe is bestowed in the same manner, and gives elasticity and rapidity in running, dancing, and leaping. The motions of the fingers do not result merely from the action of the large muscles which lie on the fore-arm: these are for the more powerful efforts; in the palm of the hand, and between the metacarpal bones, are numerous small muscles, {lumbricales and interossei,) which perforin the finer movements, —expanding the fingers, and moving them in every direction with quickness and delicacy. These small muscles, attached to the extremities of the bones of the fingers where they form the first joint, bejng inserted near the centre of motion, move the ends of the fingers with great velocity. They are the organs which give the hand the power of spinning, weaving, engraving, &c.; and as they produce the quick motions of the musician's fingers, they are called by anatomists fidicinales. But there is another use which the small muscles in the hand serve. In grasping with the hand, the strength with which it closes, when all the muscles are combined in action, must be very great; the amount of power is exhibited when we see a sailor hanging by a rope, and raising his whole body with one arm. What must be the pressure upon the hand 1 If the palms, and inside of the fingers, and their tips, were not guarded by cushions beneath the skin, it would be too much for the texture even of bones and tendons, and certainly for the blood-vessels and nerves, to sustain. The elastic pad in the foot of the horse, camel, or ostrich, is not a whit more appropriate than the fine elastic texture beneath the skin of the hand. To add to the efficacy of this yielding but strong padding, a muscle is provided, which, arising in the centre, runs across half the palm to the cushion, on the inner edge, opposed to the ball of the thumb : it acts powerfully as we grasp; and it is this muscle which, by