I cannot conceive curved lines of force without the conditions of a physical existence in that intermediate space.

I am busy just now again on Electro-Magnetism and think I have got hold of a good thing but can't say; it may be a weed instead of a fish that after all my labour I may at last pull up.

What a delight it is to think that you are quietly & philosophically at work in the pursuit of science... rather than fighting amongst the crowd of black passions & motives that seem now a days to urge men every where into action. What incredible scenes every where, what unworthy motives ruled for the moment, under high sounding phrases and at the last what disgusting revolutions.

I ... express a wish that you may, in your generation, be fit to compare to a candle; that you may, like it, shine as lights to those about you; that, in all your actions, you may justify the beauty of the taper by making your deeds honourable and effectual in the discharge of your duty to your fellow-men.

All are sure in their days except the most wise ... He is the wisest philosopher who holds his theory with some doubt.

Nothing is too wonderful to be true, if it be consistent with the laws of nature.

It is right that we should stand by and act on our principles; but not right to hold them in obstinate blindness, or retain them when proved to be erroneous.