e 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