It is not my intention to be fulsome, but I confess that I covet your skull.

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 grand thing is to be able to reason backwards.

I never guess. It is a shocking habit destructive to the logical faculty.

Our ideas must be as broad as Nature if they are to interpret Nature.

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