is made without some motive, and the
game must ever be "worth the candle."

The whole of the dramatic incidents of the night flashed across my
memory; how I had faced the fellow in my room, challenged him at the
point of my pistol, and compelled him to give me meekly proofs of his
respectability. Truly it was all humorous--but only from Despujol's
point of view.

I recollected those innocent-looking pins which apparently had been
left so carelessly in my room. Each held for me a sudden and
suspicious death.

"The slightest puncture of the skin would inevitably prove fatal," the
Professor continued. "Feeling yourself pricked you would naturally
remove the pin and very quickly afterwards death would supervene. So
prior to it you yourself would no doubt have removed all trace of the
crime!"

"It is as well that such poison is not generally known, or it would be
used by many who wished to get rid of their friends," I remarked.

The Professor laughed, and agreed, saying:

"There are several poisons of the same type which are known only to
toxicologists, and we are very careful not to allow the public
sufficient knowledge of them. I must confess that I never dreamed when
I commenced my investigations that I was in the presence of orosin.
There is sufficient in this little tube"--and he held it to the
light--"to kill a hundred persons. It certainly is one of the most
dangerous of known compounds."

"So it is evident that the man Despujol entered my room and placed the
pins there intending that I should step upon one or other of them!" I
gasped.

"Without doubt. And it seems little short of a marvel that you
escaped," said the Professor.

"It certainly does," I remarked. "But I must tell the police of the
fact you have established. The affair now assumes a new phase. The man
was not in my room with the intention of robbery, but in order to
encompass my death by secret means."

"If you had not so fortunately avoided treading upon the pins you
certainly would not be alive at the moment," remarked the Professor,
again reflectively examining the yellow fluid in the tube. "What
motive could the man have had in gaining access to your room and
placing the pins there? I suppose he did not risk putting them there
before you went to bed, as you might have picked one up on your boot,
and that would have drawn your attention to them. By placing them
there after you were in bed he hoped that, on getting out, your bare
foot wo