The doctor glanced sharply from his patient to Donaldson himself. He noted the latter's pupils, his tense lips, his tightened fingers. He had jumped at the word poison, like a murderer at the word police.
"See here," he demanded, "you have n't any of this stuff in you, have you?"
"No," answered Donaldson, calmly.
"Anything else the matter with you?"
"Nothing but nervousness, I guess. I 've been under something of a strain recently."
Donaldson turned away. He was afraid of the keen eyes of this man. Barstow had not experimented very long with the stuff; perhaps, after all, it did produce symptoms. But he reassured himself the next minute, remembering that the drug was unknown. Barstow had not revealed his discovery to any one. If he showed a dozen symptoms they would be unrecognizable.
The doctor dropped his questioning and turned to his patient. He subjected the man to the stomach-pump and hot baths. Donaldson assisted and watched every detail of the vigorous treatment with increasing interest. At the end of two hours Arsdale was allowed to sleep.
Seton put on his coat and wrote out instructions for the further care of the man. But before leaving he again turned his shrewd eyes upon Donaldson himself.
"My boy," he said kindly, "you ought to pay some attention to your own health. I hate to see a man of your age go to pieces."
He squinted curiously at Donaldson's eyes. The latter withdrew a little.