raid, 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 in 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?"

"It certainly seems probable."

"Now, you will observe that he could not have been on the staff
of the hospital, since only a man well-established in a London
practice could hold such a position, and such a one would not
drift into the country. What was he, then? If he was in the
hospital and yet not on the staff he could only have been a
house-surgeon or a house-physician--little more than a senior
student. And he left five years ago--the date is on the stick. So
your grave, middle-aged family practitioner vanishes into thin
air, my dear Watson, and there emerges a young fellow under
thirty, amiable, unambitious, absent-minded, and the possessor of
a favourite dog, which I