just a few…
“We have not yet met our Waterloo, Watson, but this is our Marengo, for it begins in defeat and ends in victory.” (The Return of Sherlock Holmes, “The Abbey Grange”)
“What you do in this world is a matter of no consequence,” returned my companion, bitterly. “The question is, what can you make people believe that you have done.” (A Study in Scarlet)
“Winwood Reade is good upon the subject,” said Holmes. “He remarks that, while the individual man is an insoluble puzzle, in the aggregate he becomes a mathematical certainty. You can, for example, never foretell what any one man will do, but you can say with precision what an average number will be up to. Individuals vary, but percentages remain constant. So says the statistician.” (The Sign of the Four)
“There are seventy-five perfumes, which it is very necessary that a criminal expert should be able to distinguish from each other, and cases have more than once within my own experience depended upon their prompt recognition.” (The Hound of the Baskervilles)