“Surely they're not cooked already?” I said.

“I haven't heard from the doctor yet,” he said; “but he promised to ring me up this evening. I'm awfully sorry to have delayed your dinner, old man. Meet me at the Lucerne grill room, Seventy-ninth and Amsterdam Avenue, to-morrow evening at seven o'clock and we'll eat together. You've been a great help to me.”

“I hope the doctor is a mental specialist,” I said; but he pushed me gently out of the room. “We'll finish our rhyme at dinner to-morrow evening.”

I went out into the night, and sorrowfully visited a Hartford Lunch.

The next evening I was at the Lucerne grill promptly. This modest chop house was one of Dulcet's favourite resorts, and I found him already sitting in one of the alcoves studying the menu. He was in fine spirits, and his quizzical blue eyes shone with a healthy lustre.

“Are you armed?” he said, mysteriously.

“What,” I cried, “are we going to do some more guinea pigs to death? It was cruel. I have scruples against taking innocent lives. Besides, your experiment proved nothing. Those pigs would have died anyway, shut up in an air-tight box like that.”

“Stuff!” he said. “The box was not hermetic. I had left small apertures: there was plenty of oxygen. No, it was not the confinement in the tin box that killed them. After you had gone, the chemist whom I had consulted called me up. My suspicions were sound. Have you ever heard of fumacetic acid?”

This is going to be terrible, I thought to myself, and ordered tenderloin steak, well done, with a double order of hashed brown potatoes.

“Have you ever heard of fumacetic acid?” he repeated, relentlessly.