research revealed absolutely nothing but a general disorganisation
of the blood-corpuscles, a most peculiar thing, but one the
significance of which none of us here can fathom. If it was poison
that he took or that had been given to him, it was the most
subtle, intangible, elusive, that ever came to my knowledge. Why,
there is absolutely no trace or clue--"

"Nor any use in looking for one in that way," broke in Kennedy
decisively. "If we are to make any progress in this case, we must
look elsewhere than to an autopsy. There is no clue beyond what
you have found, if I am right. And I think I am right. It was the
venom of the cobra."

"Cobra venom?" repeated the coroner, glancing up at a row of
technical works.

"Yes. No, it's no use trying to look it up. There is no way of
verifying a case of cobra poisoning except by the symptoms. It is
not like any other poisoning in the world."

Dr. Leslie and I looked at each other, aghast at the thought of a
poison so subtle that it defied detection.

"You think he was bitten by a snake?" I blurted out, half
incredulous.

"Oh, Walter, on Broadway? No, of course not. But cobra venom has a
medicinal value. It is sent here in small quantities for various
medicinal purposes. Then, too, it would be easy to use it. A
scratch on the hand in the passing crowd, a quick shoving of the