"Of course," Craig went on, after a pause, "we all know that Doctor Lathrop is a doctor and hence likely to dabble in almost anything relating to his profession. Perhaps he knew of the existence and the properties of the Calabar bean. Quite certainly, I should say. No doubt he has used the drug—physostigmine. In fact, he tells me he has. Very well, then. So much for that.
"Take yourself, for example. I think I recall seeing many African trophies in that very cozy den of yours. Now, the Calabar bean is well known in Africa, not only in the Calabar, on the west coast, but in many other parts of the continent that travelers and tourists visit. So, you see, although at first sight such a bean might seem to have very little to do with a prosperous broker on Broad Street, it is not impossible that a judge or jury—or a detective—might see a connection."
Kennedy paused to watch the effect of the home thrust. I cannot say that Shattuck even winced. He was a man with too much control over himself for that. I longed for some of the psychological laboratory instruments that will reveal, often, what a nerve-strong exterior hides.
"But, quite more important still," continued Kennedy, "is the fact that the bean, or rather its derivative, physostigmine—which we know was the poison that killed Wilford—is known and used by oculists for its curious effect on the pupils. Now, from what I have learned on unimpeachable authority about Mrs. Wilford as a girl, her father, Honore Chappelle, a Frenchman, was a well-known oculist. He had no sons and often used to wish that his only child had not been a girl. For a time he had some vague idea, I believe, that his daughter might take up his place in the business. However, that was merely fanciful. As Honora grew to womanhood and tasted the advantages of the not small fortune her father had piled up, the social life appealed to her. And yet, in the girlhood days, who shall say she did not learn something of the Calabar bean, of the drug, and of its properties? It would be most unlikely if she did not."
Kennedy paused for a moment, leaving Shattuck almost speechless and hiding a secret fear.
"You can draw your own conclusions from what I have just said," finished Craig. "Sometimes, you know, actions speak louder than words."
Shattuck had risen, almost angrily as two red spots of passion appeared on his face over the cheek-bones.
"Don't you think you have done enough, hounding Mrs. Wilford with your confounded science?" he demanded.
"I cannot say," replied Kennedy, coolly, reaching for his hat and deliberately turning away. "I am telling you this only for your own benefit. Good morning, sir."
Just what Kennedy was attempting I began to understand as we closed the door to the hall and turned again to the elevator. The seeking out of Shattuck was quite in keeping with the plan of campaign Craig had mapped out at the start.