This is unfortunately a world in which things find it difficult, frequently impossible, to live up to their names.

I have procured air [oxygen] ... between five and six times as good as the best common air that I have ever met with.

Will is nothing more than a particular case of the general doctrine of association of ideas, and therefore a perfectly mechanical thing.

In completing one discovery we never fail to get an imperfect knowledge of others.

It is no use speaking in soft, gentle tones if everyone else is shouting.

The more elaborate our means of our common sense is, the less the common sense it becomes.

The wisdom of one generation will be folly in the next.