"I'll get it for you," he said as he and Jack parted.

At the close of school that afternoon the janitor went to Jack's room
with a large bundle.

"Any trouble?" asked our hero.

"Not a bit," replied Socker. "He was out and I found it rolled up in
a corner, just where he had thrown it. He hasn't even cleaned it."

"So much the better," said Jack, as he gave Socker a small sum of
money. "I'll keep quiet about this, don't worry."

"I hope you will," the janitor went on. "It's against the rules for
me to do what I did, but I want to oblige you, and have you come out
all right."

"Which I think I will," Jack added.

When he was alone he opened the bundle Socker had brought. It was a
linen duster, and, as Jack saw several brown spots on it he uttered
an exclamation of satisfaction.

With his knife he scraped some substance from the garment, and placed
the particles in a test tube. Then, taking this with him, he went to
the laboratory, where he remained for some time.

Late that afternoon Jack, who had avoided his chums, took a walk
around the campus. As he came near a small building, where some of