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

We must reason in natural philosophy not from what we hope, or even expect, but from what we perceive.

Natural science is founded on minute critical views of the general order of events taking place upon our globe, corrected, enlarged, or exalted by experiments, in which the agents concerned are placed under new circumstances, and their diversified properties separately examined. The body of natural science, then, consists of facts; is analogy,-the relation of resemblance of facts by which its different parts are connected, arranged, and employed, either for popular use, or for new speculative improvements.

Nature is beautiful, and you are in her bosom. That voice of comfort which speaks in the breezes of morning, may visit your mind, that the delightful influences which the green leaves, the blue sky, the moonbeams and clouds of the evening diffuse over the universe, may in their powers of soul-healing, visit your day visions, is my desire and hope.

Fortunately science, like that nature to which it belongs, is neither limited by time nor by space. It belongs to the world, and is of no country and no age. The more we know, the more we feel our ignorance; the more we feel how much remains unknown.

Nothing tends so much to the advancement of knowledge as the application of a new instrument.

The three states of the caterpillar, larva, and butterfly have, since the time of the Greek poets, been applied to typify the human being,--its terrestrial form, apparent death, and ultimate celestial destination.