The Superfluous Finger

Why does a woman demand that a surgeon amputate part of her finger?

Jacques Futrelle created a sleuth named Professor Augustus S.F.X. Van Dusen, known as The Thinking Machine. He's American, and has many similarities with Sherlock Holmes. For example, he isn't a policeman, but he works with them on occasion, and he handily summarizes his deductions once the case is solved.

Jacques Futrelle wrote over 40 short stories featuring The Thinking Machine. He heroically died aboard the Titanic, after forcing his wife into a lifeboat.