“That’s what the doctor said. He wanted to find the bit of glass which had scratched old Ben’s tongue, and he and Dick had a hunt for it, but it must have fallen on the floor of the shop. It was only a tiny piece, anyway. Of course they never found it, but the doctor says there must have been some extraordinary powerful poison on it, and I can’t see how a bit of glass like that could get stuck on the mouthpiece of a pipe accidental like.”

“Of course, nicotine acts as a poison if it is injected into the blood,” suggested Mr. Ludgrove. “It is just possible that the fragment of glass was harmless enough, but that the nicotine in the pipe found its way into the scratch.” But Mr. Copperdock shook his head. “It was a new pipe, what hadn’t ever been smoked before,” he replied. “Bought at my place the day before, as I told you.”