“Yes, Mr. Holmes, it is as you say, sir. He does smoke something terrible. All day and sometimes all night, sir. I’ve seen that room of a morning⁠—well, sir, you’d have thought it was a London fog. Poor young Mr. Smith, he was a smoker also, but not as bad as the professor. His health⁠—well, I don’t know that it’s better nor worse for the smoking.”

“Ah!” said Holmes, “but it kills the appetite.”

“Well, I don’t know about that, sir.”

“I suppose the professor eats hardly anything?”

“Well, he is variable. I’ll say that for him.”

“I’ll wager he took no breakfast this morning, and won’t face his lunch after all the cigarettes I saw him consume.”