Some recent short publications on Chinese gunpowder and firearms are misleading... I have had valuable assistance from Dr. J. Needham... If the dates… - J. R. Partington

From the time when Guldberg and Waage gave quantitative form to the speculations of the physicist Berthollet, a clear conception of chemical equilibrium, in sharp contrast to an anthropomorphic theory of affinity dating back to Hippocrates and Barchausen, has yielded rich and abundant fruit.

The results of a scrutiny of the materials of chemical science from a mathematical standpoint are pronounced in two directions. In the first we observe crude, qualitative notions, such as fire-stuff, or phlogiston, destroyed; and at the same time we perceive definite measurable quantities such as fixed air, or oxygen, taking their place. In the second direction we notice the establishment of generalizations, laws, or theories, in which a mass of quantitative data is reduced to order and made intelligible. Such are the law of conservation of matter, the laws of chemical combination, and the atomic theory.

To a person whose experience has never been brought into relation with the object sulphur, the name signifies nothing; to the scientist... his concept involves the ideas of specific gravity, crystalline form, element, atom, and the like, derived from past experiences. His concept is distinguished from the other by involving... number or quantity.