But it must not be forgotten that ... glass and porcelain were manufactured, stuffs dyed and metals separated from their ores by mere empirical processes of art, and without the guidance of correct scientific principles.

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.

A time will come, when fields will be manured with a solution of glass (silicate of potash), with the ashes of burnt straw, and with the salts of phosphoric acid, prepared in chemical manufactories, exactly as at present medicines are given for fever and goitre.

Without an acquaintance with chemistry, the statesman must remain a stranger to the true vital interests of the state, to the means of its organic development and improvement; ... The highest economic or material interests of a country, the increased and more profitable production of food for man and animals, ... are most closely linked with the advancement and diffusion of the natural sciences, especially of chemistry.

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 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 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.