It is a mistake to confound strangeness with mystery. The most commonplace crime is often the most mysterious because it presents no new or special features from which deductions may be drawn. This murder would have been infinitely more difficult to unravel had the body of the victim been simply found lying in the roadway without any of those outré and sensational accompaniments which have rendered it remarkable. These strange details, far from making the case more difficult, have really had the effect of making it less so.

By the way, Doctor, I shall want your cooperation.' 'I shall be delighted.' 'You don't mind breaking the law?' 'Not in the least.' 'Nor running a chance of arrest?' 'Not in a good cause.' 'Oh, the cause is excellent!' 'Then I am your man.' 'I was sure that I might rely on you.

A study in scarlet, eh? Why shouldn't we use a little art jargon? There's the scarlet thread of murder running through the colourless skein of life, and our duty is to unravel it, and isolate it, and expose every inch of it.

It is always a joy to meet an American, Mr. Moulton, for I am one of those who believes that the folly of a monarch and the blundering of a minister in far-gone years will not prevent our children from being some day citizens of the same world-wide country under a flag which shall be a quartering of the Union Jack with the Stars and Stripes.

It is, I admit, mere imagination; but how often is imagination the mother of truth?

...while the individual man is an insoluble puzzle, in the aggregate he becomes a mathematical certainty.

The husband was a teetotaller, there was no other woman, and the conduct complained of was that he had drifted into the habit of winding up every meal by taking out his false teeth and hurling them at his wife.