The most valuable discoveries have found their origin in the most trivial accidents.

Our civilization depends largely on paper.

The leading distinction in magnets is the sex, male and female, and the next great difference in them is the colour. Those of Magnesia, bordering on Macedonia, are of a reddish black; those of Breotia are more red than black; and the kind that is found in Troas is black, of the female sex, and consequently destitute of attractive power.

Now, that the sovereign power and deity, whatsoever it is, should have regard of mankind, is a toy and vanity worthy to be laughed at.

There is always something new out of Africa.

The most disgraceful cause of the scarcity [of remedies] is that even those who know them do not want to point them out, as if they were going to lose what they pass on to others.

There is no book so bad that some good can not be got out of it.