I think Lyell's "Principles" will produce a considerable effect.

I hope I have given you the sort of information which you want.

My head is rather unsteady, which makes my handwriting worse than usual.
If you argue about the non-acceptance of Natural Selection, it seems to me a very striking fact that the Newtonian theory of gravitation, which seems to every one now so certain and plain, was rejected by a man so extraordinarily able as Leibnitz.

The truth will not penetrate a preoccupied mind.
Wallace (222/2.

Wallace, "Westminster Review," July, 1867.