“Well,” he replied, “as a matter of purely academic interest, there is the point that I mentioned just now. The body of this man contained a lethal quantity of arsenic. With that quantity of poison in his body, the man died. The obvious inference is that those two facts were connected as cause and effect. But it is not absolutely certain that they were. It is conceivable that the man may have died from some natural cause overlooked by the pathologist—who was already aware of the presence of arsenic, from Detling’s information; or again it is conceivable that the man may have been murdered in some other way—even by the administration of some other, more rapidly acting poison, which was never found because it was never looked for. These are undeniable possibilities. But I doubt if any reasonable person would entertain them, seeing that they are mere conjectures unsupported by any sort of evidence. And you notice that the second possibility leaves the verdict of wilful murder unaffected.”
“Yes, but it might transfer the effects of that verdict to the wrong person.”
“True,” he rejoined with a smile. “It might transfer them from a poisoner who had committed a murder to another poisoner who had only attempted to commit one; and the irony of the position would be that the latter would actually believe himself to be the murderer. But as I said, this is mere academic talk. The coroner’s verdict is the reality with which we have to deal.”
“I am not so sure of that, Thorndyke,” said I, inspired with a sudden hope by his “illustration.” “You admit that fallacies are possible and you are able to suggest two off-hand. You insist, very properly, that our opinions at present must be based exclusively on the evidence given at the inquest. But, as I listened to that evidence, I had the feeling—and I have it still—that it did not give a credible explanation of the facts that were proved. I had—and have—the feeling that careful and competent investigation might bring to light some entirely new evidence.”
“It is quite possible,” he admitted, rather drily.
“Well, then,” I pursued, “I should wish some such investigation to be made. I can recall a number of cases in which the available evidence, as in the present case, appeared to point to a certain definite conclusion, but in which investigations undertaken by you brought out a body of new evidence pointing in a totally different direction. There was the Hornby case, the case of Blackmore, deceased, the Bellingham case and a number of others in which the result of your investigations was to upset completely a well-established case against some suspected individual.”
He nodded, but made no comment, and I concluded with the question:
“Well, why should not a similar result follow in the present case?”
He reflected for a few moments and then asked:
“What is it that is in your mind, Mayfield? What, exactly do you propose?”