ked.

"You don't know it all--yet--my boy," smiled the aged professor.
"There's still something the old teacher can add to your education, and
I'm glad, Quentin, very glad, for it will draw you closer to me again. I
need you to carry on my work when I must lay it down. I'm not positive,"
he continued, "but I believe these crystals to be those of _Dhatura
stramonium_, and, as you say speed's the thing, we'll begin by noting
the effect of the stuff as a gas on that guinea-pig over there."

"Have you masks?" asked Locke, with true scientific caution.

"Yes--on the shelf. You're keen, Quentin. These fumes can penetrate the
tiniest aperture and, if my guess is right, without a mask, you would
quickly laugh yourself to death."

"Don't, Professor, don't joke, for there is no joy in that mad laughter.
It is horrible, maddening, even to the hearer. Let us get to work. The
father of the girl I love may even now be sinking to his death. We must
determine the nature of this deadly stuff, and then find an antidote."

The chemist brought out the cage in which the guinea-pig was placidly
munching a lettuce leaf, and placed it in a convenient spot on the
table. Then, after Locke, as well as the professor, had carefully
adjusted the masks, the latter lighted a Bunsen burner and applied the
flame to the deadly crystals. A pungent fume was given off and collected
in a rubber bag, or cone, from which a long tube protruded.

This tube the chemist introduced into the cage. For a moment there was
no perceptible change in the animal's actions. Then it stopped eating,
sniffed at the strange odor, and commenced to twitch violently. This
twitching continued for several minutes, when the creature started to
revolve in circles, like a Japanese dancing-mouse. Finally it became
subject to spasms, and, although the professor withdrew the tube, these
symptoms continued.

"I was right!" he cried. "It is an especially poisonous variety of that
almost unknown Oriental drug, _Dhatura stramonium_. I think I can find
an antidote to it, also. To work, my boy, to work!"

One experiment after another resulted in failure, however, and it was
while they were so engaged that the telephone bell rang and a feminine
voice inquired for Locke.

It was an excited Eva who called. "Quentin," she burst forth,
breathlessly, "what do you think has happened? The strangest thing!
Flint has escaped. Tell me what to do. Can't you come to me at once? I
need you."

Loc