"It could not. Of course that is not to say it could not be some
person's private memorandum for some combination of elements. C might
stand for carbon and H for hydrogen. But that would not make a poison
in the ordinary accepted meaning of the term. I am sure you are
mistaken if you think that is a chemical symbol."

"I am sure, also," said the detective with a smile. "I just wanted your
opinion, that is all. Then those letters and figures would mean nothing
to you?"

"Nothing at all. Wait though - "

Young Dr. Percy Baird looked at the slip again. "No, it would mean
nothing to me," he saidfinally.

"Thank you," said the colonel.

He came out of the physician's office to find Jean Forette calmly
reading in his side of the car. The paper was put away at once, and
with a whirr from the self-starter the motor throbbed.

"It there a free public library in town, Jean?" asked the detective.

"Yes, monsieur.

"Take me there."

The library was one built partly with the money donated by a celebrated
millionaire, and contained a fair variety of books. To the main desk,