“It is fortunate for this community that I am not a criminal.”

“The London criminal is certainly a dull fellow. Look out of this window, Watson. See how the figures loom up, are dimly seen, and then blend once more into the cloudbank. The thief or the murderer could roam London on such a day as the tiger does the jungle, unseen until he pounces, and then evident only to his victim. There have been numerous petty thefts. This great and sombre stage is set for something more worthy than that. It is fortunate for this community that I am not a criminal.”

“When a doctor does go wrong he is the first of criminals.”

“[O]n general principles it is best that I should not leave the country. Scotland Yard feels lonely without me, and it causes an unhealthy excitement among the criminal classes.”

“I am not a very good man, Effie, but I think that I am a better one than you have given me credit for being.”

“So swift, silent and furtive were his movements like those of a trained bloodhound picking out a scent, that I could not but think what a terrible criminal he would have made had he turned his energy and sagacity against the law instead of exerting them in its defense.”

“Man, or at least criminal man, has lost all enterprise and originality. As to my own little practice, it seems to be degenerating into an agency for recovering lost lead pencils and giving advice to young ladies from boarding-schools.”