“You will see at once that all argument upon this head should be
      urged, if at all, against the rule itself; and for this end we
      must examine the rationale of 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 inception, during
      efforts to breathe while beneath the surface, of water into the
      lungs. Much is also received into the stomach, and the whole body
      becomes heavier by the difference between the weight of the air
      originally distending these cavities, and that of the fluid which
      now fills them. This difference is sufficient to cause the body
      to sink, as a general rule; but is insufficient in the cases of
      individuals with small bones and an abnormal quantity of flaccid
      or fatty matter. Such individuals float even after drowning. “The corpse, being supposed at the bottom of the river, will
      there remain until, by some means, its specific gravity again
      becomes less than that of the bulk of water which it displaces. This effect is brought about by decomposition, or otherwise. The
      result of decomposition is the generation of gas, distending the
      cellular tissues and all the cavities, and giving the puffed
      appearance which is so horrible. When this distension has so far
      progressed that the bulk of the corpse is materially increased
      without a corresponding increase of mass or weight, its specific
      gravity becomes less than that of the water displaced, and it
      forthwith makes its appearance at the surface. But decomposition
      is modified by innumerable circumstances—is hastened or retarded
      by innumerable agencies; for example, by the heat or cold of the
      season, by the mineral impregnation or purity of the water, by
      its depth or shallowness, by its currency or stagnation, by the
      temperament of the body, by its infection or freedom from disease
      before death. Thus it is evident that we can assign no period,
      with any thing like accuracy, at which the corpse shall rise
      through decomposition. Under certain conditions this result would
      be brought about within an hour; under others, it might not take
      place at all. There are chemical infusions by which the animal
      frame can be preserved forever from corruption; the bi-chloride
      of mercury is one. But, apart from decomposition, there may be,
      and very usually is, a generation of gas within the stomach, from
      the acetous fermentation of vegetable matter (or within other
      cavities from other causes), sufficient to induce a distension
      which will bring the body to the surface. The effect produced by
      the firing of a cannon is that of simple vibration. This may
      either loosen the corpse from the soft mud or ooze in which it is
      imbedded, thus permitting it to rise when other agencies have
      already prepared it for so doing; or it may overcome the tenacity
      of some putrescent portions of the cellular tissue; allowing the
      cavities to distend under the influence of the gas. “Having thus before us the whole philosophy of this subject, we
      can easily test by it the assertions of L’Etoile. ‘All experience
      shows,’ says this paper, ‘that drowned bodies, or bodies thrown
      into the water immediately after death by violence, require from
      six to ten days for sufficient decomposition to take place to
      bring them to the top of the water. Even when a cannon is fired
      over a corpse, and it rises before at least five or six days’
      immersion, it sinks again if let alone.’

      “The whole of this paragraph must now appear a tissue of
      inconsequence and incoherence. All experience does not show that
      ‘drowned bodies’ require from six to ten days for sufficient
      decomposition to take place to bring them to the surface. Both
      science and experience show that the period of their rising is,
      and necessarily must be, indeterminate. If, moreover, a body has
      risen to the surface through firing of cannon, it will not ‘sink
      again if let alone,’ until decomposition has so far progressed as
      to permit the escape of the generated gas. But I wish to call
      your attention to the distinction which is made between ‘drowned
      bodies,’ and ‘bodies thrown into the water immediately after
      death by violence.’ Although the writer admits the distinction,
      he yet includes them all in the same category. I have shown how
      it is that the body of a drowning man becomes specifically
      heavier than its bulk of water, and that he would not sink at
      all, except for the struggles by which he elevates his arms above
      the surface, and his gasps for breath while beneath the
      surface—gasps which supply by water the place of the original air
      in the lungs.