[Illustration: "'I CALL IT THE SLEEPING DEATH,' ANSWERED THE PROFESSOR"]

"I thought," said Corbario, almost carelessly, "that there was no longer
any such thing as a poison that left no traces or signs. Can you not
generally detect vegetable poisons by the mode of death?"

"Yes," answered the Professor, returning the glass tube to its case and
the latter to his pocket. "But please to remember that although we can
prove to our own satisfaction that some things really exist, we cannot
prove that any imaginable thing outside our experience cannot possibly
exist. Imagine the wildest impossibility you can think of; you will not
induce a modern man of science to admit the impossibility of it as
absolute. Impossibility is now a merely relative term, my dear Corbario,
and only means great improbability. Now, to illustrate what I mean, it
is altogether improbable that a devil with horns and hoofs and a fiery
tail should suddenly appear, pick me up out of this delightful circle,
and fly away with me. But you cannot induce me to deny the possibility
of such a thing."

"I am so glad to hear you say that," said the Signora, who was a
religious woman.

Kalmon looked at her a moment and then broke into a peal of laughter
that was taken up by the rest, and in which the good lady joined.

"You brought it on yourself," she said at last.

"Yes," Kalmon answered. "I did. From your point of view it is better to
admit the possibility of a mediæval devil with horns than to have no
religion at all. Half a loaf is better than no bread."