Page:Mystery Tales of Edgar Allan Poe.pdf/84

 the rule. Now, the human body, in general, is neither much lighter nor much heavier than the water of the Seine; that is to say, the specific gravity of the human body, in its natural condition, is about equal to the bulk of fresh water which it displaces. The bodies of fat and fleshy persons, with small bones, and of women generally, are lighter than those of the lean and large-boned, and of men; and the specific gravity of the water of a river is somewhat influenced by the presence of the tide from sea. But, leaving this tide out of question, it may be said that very few human bodies will sink at all, even in fresh water, of their own accord. Almost any one, falling into a river, will be enabled to float, if he suffer the specific gravity of the water fairly to be adduced in comparison with his own—that is to say, if he suffer his whole person to be immersed, with as little exception as possible. The proper position for one who cannot swim, is the upright position of the walker on land, with the head thrown fully back, and immersed; the mouth and nostrils alone remaining above the surface. Thus circumstanced, we shall find that we float without difficulty and without exertion. It is evident, however, that the gravities of the body, and of the bulk of water displaced, are very nicely balanced, and that a trifle will cause either to preponderate. An arm, for instance, uplifted from the water, and thus deprived of its support, is an additional weight sufficient to immerse the whole head, while the accidental aid of the smallest piece of timber will enable us to elevate the head so as to look about. Now, in the struggles of one unused to swimming, the arms are invariably thrown upwards, while an attempt is made to keep the head in its usual perpendicular position. The result is the immersion of the mouth and nostrils, and the reception, during efforts to breathe while beneath the surface, of water into the