Revolutions are not made with rosewater.

The learned compute that seven hundred and seven millions of millions of vibrations have to penetrate the eye before the eye can distinguish the tints of a violet.

In these days half our diseases come from neglect of the body in overwork of the brain.

The first essential to success in the art you practice is respect for the art itself.

It is noticeable how intuitively in age we go back with strange fondness to all that is fresh in the earliest dawn of youth. If we never cared for little children before, we delight to see them roll in the grass over which we hobble on crutches. The grandsire turns wearily from his middle-aged, careworn son, to listen with infant laugh to the prattle of an infant grandchild. It is the old who plant young trees; it is the old who are most saddened by the autumn; and feel most delight in the returning spring.

Science is an ocean. It is as open to the cockboat as the frigate. One man carries across it a freightage of ingots, another may fish there for herrings.

Men are valued, not for what they are, but for what they seem to be.