"Yet you found none?" Mr. Mitchel smiled, and resumed his smoking.
"Yet I found none," said Mr. Barnes. "But this was a most significant fact to me. It led me to a suspicion which I proceeded to verify. The plumbing in this house is of the most approved pattern. Under the porcelain bathtub there is a patent trap for the exclusion of sewer-gas. This is so fashioned that some water always remains. Supposing that bloody water had passed through it, I should find this trap partly filled with water tinted in color. I removed the screw, which enabled me to catch the water from the trap in a bowl. It was perfectly clear. Not a trace of color."
"From which you deduced?" asked Mr. Mitchel.
"From which I deduced," said the detective, "that the woman had not been killed, or dismembered, in the house where her body was found. By examining the other houses and emptying the traps, I found one which yielded water plainly colored with blood, and I also found a few smudges about the bathtub; places where blood had splashed and been washed off. The assassin thought that he had made all clean, but as so often happens with porcelain, when dried there still remained a slight stain, which even showed the direction in which it had been wiped."
"Very good! Very good indeed!" Mr. Mitchel yawned slightly. "Let me see. You have discovered—what? That the knife was sharp. And that the woman was killed in one house and carried to another. How does that help you?"
At this point Mr. Barnes gave Mr. Mitchel a distinct surprise. Instead of answering the question, he asked suddenly:
"Mr. Mitchel, will you permit me to examine that watch-chain which you are wearing?"
Mr. Mitchel sat straight up in his chair, and looked sharply at the detective, as though trying to read his innermost thoughts. The detective stared back at him, and both were silent a moment. Then without speaking, Mr. Mitchel removed the chain, and handed it to Mr. Barnes, who took it with him to the window, and there examined it closely through a lens. Mr. Mitchel threw the remains of his cigar into the fire, and, placing both hands behind his head as he lay back in his chair, awaited developments. Presently Mr. Barnes returned to his place by the mantel, and in resuming his narrative it was noticeable from his tone of voice that he was more than ever troubled.
"You asked me," said he, "how my discoveries helped me. I say from the bottom of my soul that they have helped me only too well. That I proceed in this matter is due to the fact that I must follow the dictates of my conscience rather than my heart."
"Brutus yielded up his son," suggested Mr. Mitchel.