We may lay it down as an incontestible axiom, that, in all the operations of art and nature, nothing is created; an equal quantity of matter exists both before and after the experiment; the quality and quantity of the elements remain precisely the same; and nothing takes place beyond changes and modifications in the combination of these elements. Upon this principle the whole art of performing chemical experiments depends: We must always suppose an exact equality between the elements of the body examined and those of the products of its analysis.

Experiments upon vegetation give reason to believe that light combines with certain parts of vegetables, and that the green of their leaves, and the various colors of flowers, is chiefly owing to this combination.

A wealthy landowner cannot cultivate and improve his farm without spreading comfort and well-being around him. Rich and abundant crops, a numerous population and a prosperous countryside are the rewards for his efforts.

It is impossible to disassociate language from science...To call forth a concept, a word is needed.

We must trust to nothing but facts: These are presented to us by Nature, and cannot deceive. We ought, in every instance, to submit our reasoning to the test of experiment, and never to search for truth but by the natural road of experiment and observation.

One succeeds in obtaining an equivalent production at a lower price by improving the arts, trades and agriculture and by developing the physical and moral qualities of workers, farmers and craftsmen.

I consider nature a vast chemical laboratory in which all kinds of composition and decompositions are formed.