"That's the evidence!" he exclaimed, as he turned down a side street.

Whether it was this change, or whether it was because his ankle
suddenly healed, was not in evidence, but Jack began to walk with
scarcely the semblance of a halt in his step as soon as he was out of
sight of the students.

The lad hurried back to his room. There he spent a busy half hour,
poring over some books on chemistry. He got several test tubes, and
his apartment took on the appearance of a laboratory, while many
strange smells filled the air.

While Jack was engaged in pouring the contents of one test tube into
another there came a knock at his door.

"Who's there?" he called.

"It's me, Sam," was the reply.

"Say, Sam, excuse me, but I can't let you in," Jack answered. "I'm
working on something that I can't leave. I may have a surprise for
you in the morning."

"All right," Sam answered. "Here's some mail, that's all. I'll shove
it under the door."

There was a rustling of paper and several letters came beneath the
portal. Jack laid aside his test tube and gathered them up. One was
from his aunts at home, another from Judge Bennetty regarding the
payment of certain bills Jack had contracted, while the third was in