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

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

In completing one discovery we never fail to get an imperfect knowledge of others of which we could have no idea before, so that we cannot solve one doubt without creating several new ones.

What I have known with respect to myself, has tended much to lessen both my admiration, and my contempt, of others.

Every man, when he comes to be sensible of his natural rights, and to feel his own importance, will consider himself as fully equal to any other person whatever

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

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