ty good-looking chap yourself, Riley," said Kennedy. "I
should think you could jolly a housemaid, if necessary. Anyhow, you
can get the fellow on the beat to do it--if he isn't already to
be found in the kitchen. Why, I see a dozen ways of getting the
notepaper."

"Oh, it's me that's the lady-killer, sir," grinned Riley. "I'm a
regular Blarney stone when I'm out on a job of that sort. Sure, I'll
have some of them for you in the morning.'

"Bring me what you get, the first thing in the morning, even if
you've landed only a few samples," said Kennedy, as Riley departed,
straightening his tie and brushing his hat on his sleeve.

"And now, Walter, you too must excuse me to-night," said Craig "I've
got a lot to do, and sha'n't be up to our apartment till very late--or
early. But I feel sure I've got a strangle-hold on this mystery. If I
get those papers from Riley in good time to-morrow I shall invite you
and several others to a grand demonstration here to-morrow night.
Don't forget. Keep the whole evening free. It will be a big story."

Kennedy's laboratory was brightly lighted when I arrived early the
next evening. One by one his "guests" dropped in. It was evident that
they had little liking for the visit, but the coroner had sent out the
"invitations," and they had nothing to do but accept. Each one was
politely welcomed by the professor and assigned a seat, much as he
would have done with a group of students. The inspector and the
coroner sat back a little. Mrs. Parker, Mr. Downey, Mr. Bruce,
myself, and Miss La Neige sat in that order in the very narrow and
uncomfortable little armchairs used by the students during lectures.

At last Kennedy was ready to begin. He took his position behind the
long, flat-topped table which he used for his demonstrations before
his classes. "I realize, ladies and gentlemen," he began formally,
"that I am about to do a very unusual thing; but, as you all know, the
police and the coroner have been completely baffled by this terrible
mystery and have requested me to attempt to clear up at least certain
points in it. I will begin what I have to say by remarking that the
tracing out of a crime like this differs in nothing, except as regards
the subject-matter, from the search for a scientific truth. The
forcing of man's secrets is like the forcing of nature's secrets. Both
are pieces of detective work. The methods employed in the detection
of crime are, or rather should be, like the meth