Antoine Lavoisier Analysis Quotations

One will not deny me, I trust, all the theory of oxidation and combustion, the analysis and decomposition of air by metals and combustible bodies, the theory of acidification, more precise knowledge on the nature of a great numbers of acids, notably

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.

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.