Part 80

"The question as to the poison," said he, "remains. It is a simple one to resolve, because we've got the man who sold it to her in that closet."

"Besides," returned the doctor, "I can tell something about the poison. This rascal of a Robelot stole it from my laboratory, and I know only too well what it is, even if the symptoms, so well described by our friend Plantat, had not indicated its name to me. I was at work upon aconite when Sauvresy died; and he was poisoned with aconitine."

"Ah, with aconitine," said M. Lecoq, surprised. "It's the first time that I ever met with that poison. Is it a new thing?"

"Not exactly. Medea is said to have extracted her deadliest poisons from aconite, and it was employed in Rome and Greece in criminal executions."

"And I did not know of it! But I have very little time to study. Besides, this poison of Medea's was perhaps lost, as was that of the Borgias; so many of these things are!"

"No, it was not lost, be assured. But we only know of it nowadays by Mathiole's experiments on felons sentenced to death, in the sixteenth century; by Hers, who isolated the active principle, the alkaloid, in 1833 and lastly by certain experiments made by Bouchardat, who pretends--"

Unfortunately, when Dr. Gendron was set agoing on poisons, it was difficult to stop him; but M. Lecoq, on the other hand, never lost sight of the end he had in view.

"Pardon me for interrupting you, Doctor," said he. "But would traces of aconitine be found in a body which had been two years buried? For Monsieur Domini is going to order the exhumation of Sauvresy."

"The tests of aconitine are not sufficiently well known to permit of the isolation of it in a body. Bouchardat tried ioduret of potassium, but his experiment was not successful."

"The deuce!" said M. Lecoq. "That's annoying."

The doctor smiled benignly.

"Reassure yourself," said he. "No such process was in existence--so I invented one."

"Ah," cried Plantat. "Your sensitive paper!"

"Precisely."

"And could you find aconitine in Sauvresy's body?"

"Undoubtedly."

M. Lecoq was radiant, as if he were now certain of fulfilling what had seemed to him a very difficult task.

"Very well," said he. "Our inquest seems to be complete. The history of the victims imparted to us by Monsieur Plantat gives us the key to all the events which have followed the unhappy Sauvresy's death. Thus, the hatred of this pair, who were in appearance so united, is explained; and it is also clear why Hector has ruined a charming young girl with a splendid dowry, instead of making her his wife. There is nothing surprising in Tremorel's casting aside his name and personality to reappear under another guise; he killed his wife because he was constrained to do so by the logic of events. He could not fly while she was alive, and yet he could not continue to live at Valfeuillu. And above all, the paper for which he searched with such desperation, when every moment was an affair of life and death to him, was none other than Sauvresy's manuscript, his condemnation and the proof of his first crime."

M. Lecoq talked eagerly, as if he had a personal animosity against the Count de Tremorel; such was his nature; and he always avowed laughingly that he could not help having a grudge against the criminals whom he pursued. There was an account to settle between him and them; hence the ardor of his pursuit. Perhaps it was a simple matter of instinct with him, like that which impels the hunting hound on the track of his game.

"It is clear enough now," he went on, "that it was Mademoiselle Courtois who put an end to his hesitation and eternal delay. His passion for her, irritated by obstacles, goaded him to delirium. On learning her condition, he lost his head and forgot all prudence and reason. He was wearied, too, of a punishment which began anew each morning; he saw himself lost, and his wife sacrificing herself for the malignant pleasure of sacrificing him. Terrified, he took the resolution to commit this murder."

Many of the circumstances which had established M. Lecoq's conviction had escaped Dr. Gendron.

"What!" cried he, stupefied. "Do you believe in Mademoiselle Laurence's complicity?"

The detective earnestly protested by a gesture.

"No, Doctor, certainly not; heaven forbid that I should have such an idea. Mademoiselle Courtois was and is still ignorant of this crime. But she knew that Tremorel would abandon his wife for her. This flight had been discussed, planned, and agreed upon between them; they made an appointment to meet at a certain place, on a certain day."

"But this letter," said the doctor.

M. Plantat could scarcely conceal his emotion when Laurence was being talked about.

"This letter," cried he, "which has plunged her family into the deepest grief, and which will perhaps kill poor Courtois, is only one more scene of the infamous drama which the count has planned."

"Oh," said the doctor, "is it possible?"