from it a large-sized Norwegian knife, which he looked at critically and then handed to me. While I was inspecting the blade, he shook out the handkerchief and, having looked it over on both sides, turned to the sergeant.
"At what time did you pick up this knife?" he asked.
"About seven-fifteen, sir; directly after the hounds had started. I was careful to pick it up by the ring, and I wrapped it in the handkerchief at once."
"Seven-fifteen," said Thorndyke. "Less than half-an-hour after the murder. That is very singular. Do you observe the state of this handkerchief? There is not a mark on it. Not a trace of any bloodstain; which proves that when the knife was picked up, the blood on it was already dry. But things dry slowly, if they dry at all, in the saturated air of an autumn evening. The appearances seem to suggest that the blood on the knife was dry when it was thrown down. By the way, sergeant, what do you scent your handkerchief with?"
"Scent, sir!" exclaimed the astonished officer in indignant accents; "me scent my handkerchief! No, sir, certainly not. Never used scent in my life, sir."
Thorndyke held out the handkerchief, and the sergeant sniffed at it incredulously. "It certainly
