The book of nature which we have to read is written by the finger of God.

But I must confess I am jealous of the term atom; for though it is very easy to talk of atoms, it is very difficult to form a clear idea of their nature, especially when compounded bodies are under consideration.

I have long held an opinion, almost amounting to conviction, in common I believe with many other lovers of natural knowledge, that the various forms under which the forces of matter are made manifest have one common origin; or, in other words, are so directly related and mutually dependent, that they are convertible, as it were, one into another, and possess equivalents of power in their action.

You will be astonished when I tell you what this curious play of carbon amounts to. A candle will burn some four, five, six, or seven hours. What, then, must be the daily amount of carbon going up into the air in the way of carbonic acid! ... Then what becomes of it? Wonderful is it to find that the change produced by respiration ... is the very life and support of plants and vegetables that grow upon the surface of the earth.

The lecturer should give the audience full reason to believe that all his powers have been exerted for their pleasure and instruction.

I cannot conceive curved lines of force without the conditions of a physical existence in that intermediate space.

In place of practising wholesome self-abnegation, we ever make the wish the father to the thought: we receive as friendly that which agrees with, we resist with dislike that which opposes us; whereas the very reverse is required by every dictate of common sense.