Antoine Lavoisier

Nothing is lost, nothing is created, everything is transformed.

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.

It is impossible to make a perfect analysis of any substance, without knowing the nature of the elements of which it is composed.

The nomenclature of a science is so intimately connected with its history and its progress, that it is impossible to separate them.

The quantity of matter is the same at the beginning and at the end of every chemical operation.

Chemistry is a science of observation, experiment, and reasoning.

It is not enough to observe; we must also experiment.

The object of chemistry is to decompose bodies, and to examine the properties of the substances into which they are resolved.

We must consider as a general principle that in every operation there is an equal quantity of matter before and after the operation.

It is a truth that cannot be too often repeated, that the progress of science depends on the progress of experiment.

The more we multiply experiments, the more we shall be convinced that the elements of bodies are not simple, but compound.

The art of drawing conclusions from experiments and observations consists in knowing how to appreciate the probabilities, and to calculate the chances.

It is a capital error to believe that we can make progress in science without the aid of mathematics.

The human mind is naturally disposed to generalize, and to form systems.

The more we advance in knowledge, the more we discover our ignorance.

It is not enough to know; we must also apply.

The progress of science is slow, but sure.

The chemist, like the painter, must have a clear idea of what he wants to produce.

The more we know, the more we are able to discover.

It is by experiment that we discover the truth.