7
wholly under water, but some part will remain above, until the lungs become filled with water, which happens from drawing water into them instead of air, when a person in the fright attempts breathing while the mouth and nostrils are under water.
2. That the legs and arms are specifically lighter than salt water, and will be supported by it, so that a human body cannot sink in salt water, though the lungs were filled as above, but from the greater specific gravity of the head.
3. That therefore a person throwing himself on his back, in salt water, and extending his arms, may easily lie so as to keep his mouth and nostrils free for breathing ; and by a small motion of his hands may prevent turning, if he should perceive any tendency to it.
4. That in fresh water, if a man throw himself on his back, near the surface, he cannot long continue in that situation, but by proper action of his hands on the water. If he uses no such action, the legs and lower part of the body will gradually sink till he comes into an upright position, in which he will continue suspended, the hollow of his breast keeping the head uppermost.
5. But if, in this erect position, the head is kept upright above the shoulders, as when we stand on the ground, the immersion will, by the
