Take a position close to a smooth wall, so that one arm and hand, which are left hanging down alongside the body, are pressed over their entire length between body and wall. Try now to move the arm upward, pressing it against the wall as if you wanted to shift the latter. Apply all possible effort to this attempt, and maintain the effort for about one minute. Then step away quickly from the wall by more than the length of the arm, while keeping the arm hanging down by the side of the body in a state of complete relaxation. Provided all conditions are properly fulfilled, the arm will be found rising by itself in accordance with the aim of the earlier effort, until it reaches the horizontal. If the arm is then lowered again and left to itself, it will at once rise again, though not quite so high as before. This can be repeated several times until the last vestige of the automatic movement has faded away.