He had never said as much before, and I must admit that his words gave me keen pleasure, for I had often been piqued by his indifference to my admiration and to the attempts which I had made to give publicity to his methods. I was proud, too, to think that I had so far mastered his system as to apply it in a way which earned his approval. He now took the stick from my hands and examined it for a few minutes with his naked eyes. Then with an expression of interest he laid down his cigarette, and carrying the cane to the window, he looked over it again with a convex lens.

“Interesting, though elementary,” said he as he returned to his favourite corner of the settee. “There are certainly one or two indications upon the stick. It gives us the basis for several deductions.”

“Has anything escaped me?” I asked with some self-importance. “I trust that there is nothing of consequence which I have overlooked?”

“I am afraid, my dear Watson, that most of your conclusions were erroneous. When I said that you stimulated me I meant, to be frank, that in noting your fallacies I was occasionally guided towards the truth. Not that you are entirely wrong in this instance. The man is certainly a country practitioner. And he walks a good deal.”

“Then I was right.”

“To that extent.”

“But that was all.”

“No, no, my dear Watson, not all—by no means all. I would suggest, for example, that a presentation to a doctor is more likely to come from a hospital than from a hunt, and that when the initials ‘C.C.’ are placed before that hospital the words ‘Charing Cross’ very naturally suggest themselves.”

“You may be right.”

“The probability lies in that direction. And if we take this as a working hypothesis we have a fresh basis from which to start our construction of this unknown visitor.”

“Well, then, supposing that ‘C.C.H.’ does stand for ‘Charing Cross Hospital,’ what further inferences may we draw?”

“Do none suggest themselves? You know my methods. Apply them!”

“I can only think of the obvious conclusion that the man has practised in town before going to the country.”

“I think that we might venture a little farther than this. Look at it in this light. On what occasion would it be most probable that such a presentation would be made? When would his friends unite to give him a pledge of their good will? Obviously at the moment when Dr. Mortimer withdrew from the service of the hospital in order to start a practice for himself. We know there has been a presentation. We believe there has been a change from a town hospital to a country practice. Is it, then, stretching our inference too far to say that the presentation was on the occasion of the change?”