Rummaging about in the drawer of the table, I had come to a
package of gold-tipped cigarettes which had interested me and I
had left them out. Kennedy was now looking at them curiously.

"What is to be the method, do you suppose?" I asked.

"By a poison that is among the most powerful, approaching even
cyanogen," he replied confidently, tapping the cigarettes. "Do you
smell the odor in this room? What is it like?"

"Stale tobacco," I replied.

"Exactly--nicotine. Two or three drops on the mouth-end of a cigar
or cigarette. The intended victim thinks it is only natural. But
it is the purest form of the deadly alkaloid--fatal in a few
minutes, too."

He examined the thin little cigarettes more carefully. "Nicotine,"
he went on, "was about the first alkaloid that was recovered from
the body by chemical analysis in a homicide case. That is the
penetrating, persistent odor you smelled at Fortescue's and also
here. It's a very good poison--if you are not particular about
being discovered. A pound of ordinary smoking tobacco contains
from a half to an ounce of it. It is almost entirely consumed by
combustion; otherwise a pipeful would be fatal. Of course they may
have thought that investigators would believe that their victims
were inveterate smokers. But even the worst tobacco fiend wouldn't
show traces of the weed to such an extent."