“Were it my purpose,” continued Dupin, “merely to make out a case against this passage of L’Etoile’s argument, I might safely leave it where it is. It is not, however, with L’Etoile that we have to do, but with truth. The sentence in question has but one meaning, as it stands; and this meaning I have fairly stated, but it is material that we go behind the mere words, for an idea which these words have obviously intended, and failed to convey. It was the design of the journalists to say that at whatever period of the day or night of Sunday this murder was committed, it was improbable that the assassins would have ventured to bear the corpse to the river before midnight. And herein lies, really, the assumption of which I complain. It is assumed that the murder was committed at such a position, and under such circumstances, that the bearing it to the river became necessary. Now, the assassination might have taken place upon the river’s brink, or on the river itself; and, thus, the throwing the corpse in the water might have been resorted to at any period of the day or night, as the most obvious and most immediate mode of disposal. You will understand that I suggest nothing here as probable, or as coincident with my own opinion. My design, so far, has no reference to the facts of the case. I wish merely to caution you against the whole tone of L’Etoile’s suggestion, by calling your attention to its ex-parte character at the outset.
“Having prescribed thus a limit to suit its own preconceived notions; having assumed that, if this were the body of Marie, it could have been in the water but a very brief time, the journal goes on to say:
All experience has shown 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.
“These assertions have been tacitly received by every paper in Paris, with the exception of Le Moniteur.14 This latter print endeavors to combat that portion of the paragraph which has reference to ‘drowned bodies’ only, by citing some five or six instances in which the bodies of individuals known to be drowned were found floating after the lapse of less time than is insisted upon by L’Etoile. But there is something excessively unphilosophical in the attempt, on the part of Le Moniteur, to rebut the general assertion of L’Etoile, by a citation of particular instances militating against that assertion. Had it been possible to adduce fifty instead of five examples of bodies found floating at the end of two or three days, these fifty examples could still have been properly regarded only as exceptions to L’Etoile’s rule, until such time as the rule itself should be confuted. Admitting the rule, (and this Le Moniteur does not deny, insisting merely upon its exceptions,) the argument of L’Etoile is suffered to remain in full force; for this argument does not pretend to involve more than a question of the probability of the body having risen to the surface in less than three days; and this probability will be in favor of L’Etoile’s position until the instances so childishly adduced shall be sufficient in number to establish an antagonistical rule.
“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 the sea. But, leaving this tide out of the 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 upward, 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 case 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 anything 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