The impossibility of separating the nomenclature of a science from the science itself, is owing to this, that every branch of physical science must consist of three things; the series of facts which are the objects of the science, the ideas which represent these facts, and the words by which these ideas are expressed. Like three impressions of the same seal, the word ought to produce the idea, and the idea to be a picture of the fact.

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.

Sulfur, when burning, absorbs oxygen gas; the resulting acid is considerably heavier than the sulfur burned; its weight is equal to the sum of weights of the sulfur burned and the oxygen absorbed.

It required 85 parts by weight of oxygen and 15 parts of hydrogen to compose 100 parts of water.

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.

Nothing is lost, nothing is created, everything is transformed

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