Occasionally and frequently the exercise of the judgment ought to end in absolute reservation. It may be very distasteful, and great fatigue, to suspend a conclusion; but as we are not infallible, so we ought to be cautious; we shall eventually find our advantage, for the man who rests in his position is not so far from right as he who, proceeding in a wrong direction, is ever increasing his distance.

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.

You will be astonished when I tell you what this curious play of carbon amounts to. A candle will burn some four, five, six, or seven hours. What, then, must be the daily amount of carbon going up into the air in the way of carbonic acid! ... Then what becomes of it? Wonderful is it to find that the change produced by respiration ... is the very life and support of plants and vegetables that grow upon the surface of the earth.

When I consider the multitude of associated forces which are diffused through nature - when I think of that calm balancing of their energies which enables those most powerful in themselves, most destructive to the world's creatures and economy, to dwell associated together and be made subservient to the wants of creation, I rise from the contemplation more than ever impressed with the wisdom, the beneficence, and grandeur, beyond our language to express, of the Great Disposer of us all.

A man who is certain he is right is almost sure to be wrong.

Lectures which really teach will never be popular; lectures which are popular will never really teach.

Your remarks upon chemical notation with the variety of systems which have arisen, &c., &c., had almost stirred me up to regret publicly that such hindrances to the progress of science should exist. I cannot help thinking it a most unfortunate thing that men who as experimentalists & philosophers are the most fitted to advance the general cause of science & knowledge should by promulgation of their own theoretical views under the form of nomenclature, notation, or scale, actually retard its progress.