To make others believe that the dying
man was out of his mind--it was the very corner-stone of the edifice
reared by the petty lawyer. The morning's incident had done Fraisier
good service; but for him, La Cibot in her trouble might have fallen
into the snare innocently spread by Schmucke, when he asked her to
send back the person sent by the family.

Remonencq saw Dr. Poulain coming towards them, and asked no better
than to vanish. The fact was that for the last ten days the Auvergnat
had been playing Providence in a manner singularly displeasing to
Justice, which claims the monopoly of that part. He had made up his
mind to rid himself at all costs of the one obstacle in his way to
happiness, and happiness for him meant capital trebled and marriage
with the irresistibly charming portress. He had watched the little
tailor drinking his herb-tea, and a thought struck him. He would
convert the ailment into mortal sickness; his stock of old metals
supplied him with the means.

One morning as he leaned against the door-post, smoking his pipe and
dreaming of that fine shop on the Boulevard de la Madeleine where Mme.
Cibot, gorgeously arrayed, should some day sit enthroned, his eyes
fell upon a copper disc, about the size of a five-franc piece, covered
thickly with verdigris. The economical idea of using Cibot's medicine
to clean the disc immediately occurred to him. He fastened the thing
in a bit of twine, and came over every morning to inquire for tidings
of his friend the tailor, timing his visit during La Cibot's visit to
her gentlemen upstairs. He dropped the disc into the tumbler, allowed
it to steep there while he talked, and drew it out again by the string
when he went away.

The trace of tarnished copper, commonly called verdigris, poisoned the
wholesome draught; a minute dose administered by stealth did
incalculable mischief. Behold the results of this criminal
homoeopathy! On the third day poor Cibot's hair came out, his teeth
were loosened in their sockets, his whole system was deranged by a
scarcely perceptible trace of poison. Dr. Poulain racked his brains.
He was enough of a man of science to see that some destructive agent
was at work. He privately carried off the decoction, analyzed it
himself, but found nothing. It so chanced that Remonencq had taken
fright and omitted to dip the disc in the tumbler that day.

Then Dr. Poulain fell back on himself and science and got out of the
difficulty with a theory.