e was
too distrustful, however; and, by quitting Paris, she escaped the
destruction that was lurking for her.

The Marquise had undertaken these murders to please her lover. She was
now anxious to perpetrate another on her own account. She wished to
marry Sainte Croix; but, though separated from her husband, she was not
divorced. She thought it would be easier to poison him than to apply to
the tribunals for a divorce, which might, perhaps, be refused. But
Salute Croix had no longer any love for his guilty instrument. Bad men
do not admire others who are as bad as themselves. Though a villain
himself, he had no desire to marry one, and was not at all anxious for
the death of the Marquis. He seemed, however, to enter into the plot,
and supplied her with poison for her husband: but he took care to
provide a remedy. La Brinvilliers poisoned him one day, and Sainte
Croix gave him an antidote the next. In this manner he was buffetted
about between them for some time, and finally escaped with a ruined
constitution and a broken heart.

But the day of retribution was at hand, and a terrible mischance
brought the murders to light. The nature of the poisons compounded by
Salute Croix was so deadly, that, when working in his laboratory, he
was obliged to wear a mask, to preserve himself from suffocation. One
day, the mask slipped off, and the miserable wretch perished in his
crimes. His corpse was found, on the following morning, in the obscure
lodging where he had fitted up his laboratory. As he appeared to be
without friends or relatives, the police took possession of his
effects. Among other things was found a small box, to which was affixed
the following singular document:--

"I humbly beg, that those into whose hands this box may fall, will do
me the favour to deliver it into the hands only of the Marchioness de
Brinvilliers, who resides in the Rue Neuve St. Paul, as everything it
contains concerns her, and belongs to her alone; and as, besides, there
is nothing in it that can be of use to any person but her. In case she
shall be dead before me, it is my wish that it be burned, with
everything it contains, without opening or altering anything. In order
that no one may plead ignorance, I swear by the God that I adore, and
by all that is held most sacred, that I assert nothing but the truth:
and if my intentions, just and reasonable as they are, be thwarted in
this point by any persons, I charge their consciences with it, b