The finest imagination in the world could not have conceived of a better idea than the philosophers' stone to inspire the minds and faculties of men. Without it, chemistry would not be what it is today. In order to discover that no such thing as the philosopher's stone existed, it was necessary to ransack and analyze every substance known on earth. And in precisely this lay its miraculous influence.

The person who observes a clock, sees in it not only the pendulum swinging to and fro, and the dial-plate, and the hands moving, for a child can see all this; but he sees also the parts of the clock, and in what connexion the suspended weight stands to the wheel-work, and the pendulum to the moving hands.

If it is impossible to judge merit and guilt in the field of natural science, then it is not possible in any field, and historical research becomes an idle, empty activity.

If you want to become a chemist, you will have to ruin your health. If you don't ruin your health studying, you won't accomplish anything these days in chemistry. Liebig's advice to Kekulé.

Only about seventy years ago was chemistry, like a grain of seed from a ripe fruit, separated from the other physical sciences. With Black, Cavendish and Priestley, its new era began. Medicine, pharmacy, and the useful arts, had prepared the soil upon which this seed was to germinate and to flourish.

In the progressive growth of astronomy, physics or mechanical science was developed, and when this had been, to a certain degree, successfully cultivated, it gave birth to the science of chemistry.

The more fodder, the more flesh; the more flesh, the more manure; the more manure, the more grain.