If a gentleman walks into my room smelling of iodoform, with a black mark of nitrate of silver upon his right forefinger, and a bulge on the right side of his top-hat to show where he has secreted his stethoscope, I must be dull, indeed, if I do not pronounce him to be an active member of the medical profession.
In: William S. Baring-Gould (ed.), The Annotated Sherlock Holmes (Volume 1)