Hornung's John Dollar.

Illustration by Frederic Dorr Steele from "The Physician Who Healed Himself"
by E. W. Hornung. Everybody's Magazine, May 1913, p. 599.

On the Interesting Literature blog, Oliver Tearle (Loughborough University) discusses criminal psychologist John Dollar, created by Arthur Conan Doyle's brother-in-law E. W. Hornung. The Dollar stories can be read here.