A study of family portraits is enough to convert a man to the theory of reincarnation.

Mr. Sherlock Holmes, who was usually very late in the mornings, save upon those not infrequent occasions when he was up all night, was seated at the breakfast table. I stood upon the hearth-rug and picked up the stick which our visitor had left behind him the night before.

His incredible untidiness, his addiction to music at strange hours, his occasional revolver practice within doors, his weird and often malodorous scientific experiments, and the atmosphere of violence and danger which hung around him made him the very worst tenant in London.

I had ... come to an entirely erroneous conclusion, which shows, my dear Watson, how dangerous it always is to reason from insufficient data.

The more outré and grotesque an incident is the more carefully it deserves to be examined.

You're not hurt, Watson? For God's sake, say that you are not hurt!" It was worth a wound -- it was worth many wounds -- to know the depth of loyalty and love which lay behind that cold mask. The clear, hard eyes were dimmed for a moment, and the firm lips were shaking. For the one and only time I caught a glimpse of a great heart as well as of a great brain. All my years of humble but single-minded service culminated in that moment of revelation.

It is not really difficult to construct a series of inferences, each dependent upon its predecessor and each simple in itself. If, after doing so, one simply knocks out all the central inferences and presents one's audience with the starting-point and the conclusion, one may produce a startling, though perhaps a meretricious, effect.