Do you know anything on earth which has not a dangerous side if it is mishandled and exaggerated?

There are always some lunatics about. It would be a dull world without them.

Ex-Professor Moriarty of mathematical celebrity... is the Napoleon of crime, Watson.

Work is the best antidote to sorrow, my dear Watson.

I am engaged in answering that Italian buffoon, Mazotti, whose views upon the larval development of the tropical termites have excited my derision and contempt . . .

There is no satisfaction in vengeance unless the offender has time to realize who it is that strikes him, and why retribution has come upon him.

His love of danger, his intense appreciation of the drama of an adventure--all the more intense for being held tightly in--his consistent view that every peril in life is a form of sport, a fierce game betwixt you and Fate, with Death as a forfeit, made him a wonderful companion at such hours.