"Please sit here," he went on, "and slip your left arm into this leather sleeve. It's a little tight because it has a rubber lining, but you won't mind it after a minute or two."
Groener walked to the chair and then drew back. "What are you going to do to me?" he asked.
"We are going to show you some magic lantern pictures," answered the doctor.
"Why must I sit in this chair? Why do you want my arm in that leather thing?"
"I told you, Groener," put in the judge, "that we were coming here for the visual test; it's part of your examination. Some pictures of persons and places will be thrown on that sheet and, as each one appears, I want you to say what it is. Most of the pictures are familiar to everyone."
"Yes, but the leather sleeve?" persisted the prisoner.
"The leather sleeve is like the stop watch, it records your emotions. Sit down!"
Groener hesitated and the guard pushed him toward the chair. "Wait!" he said. "I want to know how it records my emotions."
The magistrate answered with a patience that surprised M. Paul. "There is a pneumatic arrangement," he explained, "by which the pulsations of your heart and the blood pressure in your arteries are registered—automatically. Now then! I warn you if you don't sit down willingly—well, you had better sit down."
Coquenil was watching closely and, through the prisoner's half shut eyes, he caught a flash of anger, a quick clenching of the freed hands and then—then Groener sat down.