This theory [the oxygen theory] is not as I have heard it described, that of the French chemists, it is mine (elle est la mienne); it is a property which I claim from my contemporaries and from posterity.

The whole art of making experiments in chemistry is founded on the principle: we must always suppose an exact equality or equation between the principles of the body examined and those of the products of its analysis.

The art of drawing conclusions from experiments and observations consists in evaluating probabilities and in estimating whether they are sufficiently great or numerous enough to constitute proofs. This kind of calculation is more complicated and more difficult than it is commonly thought to be. . . .

Languages are true analytical methods.

In performing experiments, it is necessary... that they be simplified as much as possible, and that every circumstance that could complicate the results should be completely removed.

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

Nothing is born, nothing dies.