particular course the criminality will take. There is an infinite distinction between the print of a robber and murderer; you can easily detect the difference between a man who would commit arson and one who would commit rape. You can tell the degree of cruelty to be used in the crime; whether the crime is to be committed with passion, cold blood, stealth, cunning.”
Neither spoke for a time. Each watched the other through eyes accustomed to the dim light of the study. The professor, who had given his account with rare enthusiasm, waited for questions: he expected no one to listen to the simplest lecture without asking questions—a habit acquired in the classroom.
“Aren’t the thumbs the same in a kid as when he grows up?”
“The designs on the thumbs never change.”
“Then you can tell whether a newborn baby is going to be a murderer?”
“As surely as you can tell its sex.”
“Gosh, I’m not going to let you see any of my thumb-prints.”
The professor removed his spectacles and toyed with them before answering.
“You’ll find some of our best friends are murderers. Some haven’t killed anyone as yet, to be sure, but they will in time, just as surely as an object thrown into the air will fall to ground at a certain rate of speed. Psychological laws are as fixed as physical laws.”
“But there must be a chance for exceptions or mistakes.”
“None at all. A science that permits of exceptions or mistakes is no science.”
The professor stopped to emphasize the statement.
“I have succeeded in formulating a new science. I’ve studied the thumb-prints of ten thousand criminals, and only one apparent exception did I find. He was an old man serving a life term for murder of the most brutal type; yet his thumb-print was that of an innocent man. I obtained all the records of his trial and found that the evidence against him was purely circumstantial. That man was innocent; and if it hadn’t been for the dread of revealing my system prematurely, I would have taken the matter up with the governor. I might have freed the man, but it would have imperiled the system. My system is infallible.”
Steel smiled as he said, “Of course, Professor Sanders, I believe every word you say, but it’s rather hard to swallow. If you’ve really accomplished what you say, you’ve done the greatest work of the century. Why, it won’t be possible for a guilty person to escape.”
“They might cut their thumbs off, but the absence of thumbs would be considered conclusive evidence of guilt after my system has supplanted the antiquated notions of criminal procedure now in vogue.”
Steel arose, walked over to the desk, and nervously played with various articles scattered about, as he talked.
“Professor,” he began from his newly assumed position, “would you make a test for me? Suppose I bring you five or six thumb-prints, will you tell me whether their owners are criminals or not?”
“You demand final proof? Well, I scarcely can object, even though it hurts my vanity. You bring me the prints, and I’ll convince even you.”
The doorbell rang, not clamorously as an hour ago, but persistently.
“There they go again,” lamented Sanders.
“Why don’t you disconnect the bell, if the ringing annoys you?”
“That is a good suggestion. How does one accomplish that result?”
“I’ll do it for you,” volunteered Steel, starting for the tiny kitchen
