I remarked that, while all the witnesses agreed in supposing the gruff voice to be that of a Frenchman, there was much disagreement in regard to the shrill, or, as one individual termed it, the harsh voice.
"That was the evidence itself," said Dupin, "but it was not the peculiarity of the evidence. You have observed nothing distinctive. Yet there was something to be observed. The witnesses, as you remark, agreed about the gruff voice; they were here unanimous. But in regard to the shrill voice, the peculiarity is—not that they disagreed—but that, while an Italian, an Englishman, a Spaniard, a Hollander, and a Frenchman attempted to describe it, each one spoke of it as that of a foreigner. Each is sure that it was not the voice of one of his own countrymen. Each likens it—not to the voice of an individual of any nation with whose language he is conversant—but the converse. The Frenchman supposes it the voice of a Spaniard, and 'might have distinguished some words had he been acquainted with the Spanish. The Dutchman maintains it to have been that of a Frenchman; but we find it stated that 'not understanding French this witness was examined through an interpreter. The Englishman thinks it the voice of a German, and does not understand German. The Spaniard 'is sure' that it was that of an Englishman, but 'judges by the intonation' altogether, 'as he has no knowledge of the English. The Italian believes it the voice of a Russian, but 'has never conversed with a native of Russia. A second Frenchman differs, moreover, with the first, and is positive that the voice was that of an Italian; but, not being cognizant of that tongue, is, like the Spaniard, 'convinced by the intonation.' Now, how strangely unusual must that voice have really been, about which such testimony as this could have been elicited!—in whose tones, even, denizens of the five great divisions of Europe could recognise nothing familiar! You will say that it might have been the voice of an Asiatic—of an African. Neither Asiatics nor Africans abound in Paris; but, without denying the inference, I will now merely call your attention to three points. The voice is termed by one witness 'harsh rather than shrill.' It is represented by two others to have been 'quick and unequal.' No words—no sounds resembling words—were by any witness mentioned as distinguishable.
"I know not," continued Dupin, "what impression I may have made, so far, upon your own understanding; but I do not hesitate to say that legitimate deductions even from this portion of the testimony—the portion respecting the gruff and shrill voices—are in themselves sufficient to engender a suspicion which should give direction to all farther progress in the investigation of the mystery. I said 'legitimate deductions;' but my meaning is not thus fully expressed. I designed to imply that the deductions are the sole proper ones, and that the suspicion arises inevitably from them as the single result. What the suspicion is, however, I will not say just yet. I merely wish you to bear in mind that, with myself, it was sufficiently forcible to give a definite form—a certain tendency—to my inquiries in the chamber.
"Let us now transport ourselves, in fancy, to this chamber. What shall we first seek here? The means of egress employed by the murderers. It is not too much to say that neither of us believe in præternatural events. Madame and Mademoiselle L'Espanaye were not destroyed by spirits. The doers of the deed were material, and escaped materially. Then how? Fortunately, there is but one mode of reasoning upon the point, and that mode must lead us to a definite decision. Let us examine, each by each, the possible means of egress. It is clear that the assassins were in the room where Mademoiselle L'Espanaye was found, or at least in the room adjoining, when the party ascended the stairs. It is then only from these two apartments that we have to seek issues. The police have laid bare the floors, the ceilings, and the masonry of the walls, in every direction. No secret issues could have escaped their vigilance. But, not trusting to their eyes, I examined with my own. There were, then, no secret issues. Both doors leading from the rooms into the passage were securely locked, with the keys inside. Let us turn to the chimneys. These, although of ordinary width for some eight or ten feet above the hearths, will not admit, throughout their extent, the body of a large cat. The impossibility of egress, by means already stated, being thus absolute, we are reduced to the windows. Through those of the front room no one could have escaped without notice from the crowd in the street. The murderers must have passed, then, through those of the back room. Now, brought to this conclusion in so unequivocal a manner as we are, it is not our part, as reasoners, to reject it on account of apparent impossibilities. It is only left for us to prove that these apparent 'impossibilities' are, in reality, not such.
"There are two windows in the chamber. One of them is unobstructed by furniture, and is wholly visible. The lower portion of the other is hidden from view by the head of the unwieldy bedstead which is thrust close up against it. The former was found securely fastened from within. It resisted the utmost force of those who endeavored to raise it. A large gimlet-hole had been pierced in its frame to the left, and a very stout nail was found fitted therein, nearly to the head. Upon examining the other window, a similar nail was seen similarly fitted in it; and a vigorous attempt to raise this sash, failed also. The police were now entirely satisfied that egress had not been in these directions. And, therefore, it was thought a matter of supererogation to withdraw the nails and open the windows.
"My own examination was somewhat more particular, and was so for the reason I have just given—because here it was, I knew, that all apparent impossibilities must be proved to be not such in reality.
"I proceeded to think thus—a posteriori. The murderers did escape from one of these windows. This being so, they could not have refastened the sashes from the inside, as they were found fastened;—the consideration which put a stop, through its obviousness, to the scrutiny of the police in this quarter. Yet the sashes were fastened. They must, then, have the power of fastening themselves. There was no escape from this conclusion. I stepped to the unobstructed casement, withdrew the nail with some difficulty and attempted to raise the sash. It resisted all my efforts, as I had anticipated. A concealed spring must, I now know, exist; and this corroboration of my idea convinced me that my premises at least, were correct, however mysterious still appeared the circumstances attending the nails. A careful search soon brought to light the hidden spring. I pressed it, and, satisfied with the discovery, forbore to upraise the sash.
"I now replaced the nail and regarded it attentively. A person passing out through this window might have reclosed it, and the spring would have caught—but the nail could not have been replaced. The conclusion was plain, and again narrowed in the field of my investigations. The assassins must have escaped through the other window. Supposing, then, the springs upon each sash to be the same, as was probable, there must be found a difference between the nails, or at least between the modes of their fixture. Getting upon the sacking of the bedstead, I looked over the head-board minutely at the second casement. Passing my hand down behind the board, I readily discovered and pressed the spring, which was, as I had supposed, identical in character with its neighbor. I now looked at the nail. It was as stout as the other, and apparently fitted in the same manner—driven in nearly up to the head.
"You will say that I was puzzled; but, if you think so, you must have misunderstood the nature of the inductions. To use a sporting phrase, I had not been once 'at fault.' The scent had never for an instant been lost. There was no flaw in any link of the chain. I had traced the secret to its ultimate result,—and that result was the nail. It had, I say, in every respect, the appearance of its fellow in the other window; but this fact was an absolute nullity (conclusive us it might seem to be) when compared with the consideration that here, at this point, terminated the clew. 'There must be something wrong,' I said, 'about the nail.' I touched it; and the head, with about a quarter of an inch of the shank, came off in my fingers. The rest of the shank was in the gimlet-hole where it had been broken off. The fracture was an old one (for its edges were incrusted with rust), and had apparently been accomplished by the blow of a hammer, which had partially imbedded, in the top of the bottom sash, the head portion of the nail. I now carefully replaced this head portion in the indentation whence I had taken it, and the resemblance to a perfect nail was complete—the fissure was invisible. Pressing the spring, I gently raised the sash for a few inches; the head went up with it, remaining firm in its bed. I closed the window, and the semblance of the whole nail was again perfect.