ch as 'house,'
'music,' 'tree,' 'baby,' that have no particular significance; among these
words, however, we have introduced thirty that have some association with
this crime, words like 'Ansonia,' 'billiards,' 'pistol.' Do you
understand?"

"Yes."

"I shall speak these words slowly, one by one, and when I speak a word I
want you to speak another word that my word suggests. For example, if I say
'tree,' you might say 'garden,' if I say 'house,' you might say 'chair.' Of
course you are free to say any word you please, but you will find yourself
irresistibly drawn toward certain ones according as you are innocent or
guilty.

"For instance, Martinez, the Spaniard, was widely known as a billiard
player. Now, if I should say 'billiard player,' and you had no personal
feeling about Martinez, you might easily, by association of ideas, say
'Spaniard'; but, if you had killed Martinez and wished to conceal your
crime then, when I said 'billiard player' you would _not_ say 'Spaniard,'
but would choose some innocent word like table or chalk. That is a crude
illustration, but it may give you the idea."

"And is that all?" asked Groener, in evident relief.

"No, there is also the time taken in choosing a word. If I say 'pen' or
'umbrella' it may take you three quarters of a second to answer 'ink' or
'rain,' while it may take another man whose mind acts slowly a second and a
quarter or even more for his reply; each person has his or her average time
for the thought process, some longer, some shorter. But that time process
is always lengthened after one of the critical or emotional words, I mean
if the person is guilty. Thus, if I say, 'Ansonia' to you, and you are the
murderer of Martinez, it will take you one or two or three seconds longer
to decide upon a safe answering word than it would have taken if you were
_not_ the murderer and spoke the first word that came to your tongue. Do
you see?"

"I see," shrugged the prisoner, "but--after all, it's only an experiment,
it never would carry weight in a court of law."

"Never is a long time," said the judge. "Wait ten years. We have a
wonderful mental microscope here and the world will learn to use it. _I_
use it now, and I happen to be in charge of this investigation."

Groener was silent, his fine dark eyes fixed keenly on the judge.

"Do you really think," he asked presently, while the old patronizing smile
flickered about his mouth, "that if I were guilty of this crime I co