The wealth and prosperity of the country are only the comeliness of the body, the fullness of the flesh and fat; but the spirit is independent of them; it requires only muscle, bone and nerve for the true exercise of its functions. We cannot lose our liberty, because we cannot cease to think.

James Watt was equally distinguished as a natural philosopher and chemist; his inventions demonstrate his profound knowledge of those sciences, and that peculiar characteristic of genius - the union of them for practical application.

This sentiment of self-contempt is a frequent one in young people of both sexes. Their valuation of themselves varies as much as the barometer, and is as much affected by outward causes.

Experimental science hardly ever affords us more than approximations to the truth; and whenever many agents are concerned we are in great danger of being mistaken.

Consistency in opinion is the slow poison of intellectual life, the destroyer of its vividness and energy.

Mr. Dalton's permanent reputation will rest upon his having discovered a simple principle, universally applicable to the facts of chemistry - in fixing the proportions in which bodies combine, and thus laying the foundation for future labors... his merits in this respect resemble those of Kepler in astronomy.

Profound minds are the most likely to think lightly of the resources of human reason, and it is the superficial thinker who is generally strongest in every kind of unbelief.