here does the college professor come in?" I asked, rather
doubtfully.

"You must remember, Walter," he pursued, warming up to his subject,
"that it's only within the last ten years or so that we have had the
really practical college professor who could do it. The silk-stockinged
variety is out of date now. To-day it is the college professor who is
the third arbitrator in labour disputes, who reforms our currency, who
heads our tariff commissions, and conserves our farms and forests. We
have professors of everything--why not professors of crime?"

Still, as I shook my head dubiously, he hurried on to clinch his point.
"Colleges have gone a long way from the old ideal of pure culture. They
have got down to solving the hard facts of life--pretty nearly all,
except one. They still treat crime in the old way, study its statistics
and pore over its causes and the theories of how it can be prevented.
But as for running the criminal himself down, scientifically,
relentlessly--bah! we haven't made an inch of progress since the hammer
and tongs method of your Byrnes."

"Doubtless you will write a thesis on this most interesting subject," I
suggested, "and let it go at that."

"No, I am serious," he replied, determined for some reason or other to
make a convert of me. "I mean exactly what I say. I am going to apply
science to the detection of crime, the same sort of methods by which you
trace out the presence of a chemical, or run an unknown germ to earth.
And before I have gone far, I am going to enlist Walter Jameson as an
aide. I think I shall need you in my business."

"How do I come in?"

"Well, for one thing, you will get a scoop, a beat,--whatever you call
it in that newspaper jargon of yours."

I smiled in a skeptical way, such as newspapermen are wont to affect
toward a thing until it is done--after which we make a wild scramble to
exploit it.

Nothing more on the subject passed between us for several days.

I. The Silent Bullet

"Detectives in fiction nearly always make a great mistake," said Kennedy
one evening after our first conversation on crime and science. "They
almost invariably antagonize the regular detective force. Now in real
life that's impossible--it's fatal."

"Yes," I agreed, looking up from reading an account of the failure of a
large Wall Street brokerage house, Kerr Parker & Co., and the peculiar
suicide of Kerr Parker. "Yes, it's impossible, just as it is impossible
for the regular