Fellow and Prælector in Chemistry of Gonville and Caius College, Cambridge

"The great object, in trying to understand history, political,
religious, literary, or scientific, is to get behind men, and to grasp
ideas."
LORD ACTON'S LETTERS.

"Dans l'étude de la nature, comme dans la pratique de l'art,
il n'est pas donné à l'homme d'arriver au but sans laisser des
traces des fausses routes qu'il a tenues."

GUYTON DE MORVEAU, in Encyclopédie Méthodique (1786).

JOHN WILEY & SONS

LONDON: CHAPMAN & HALL, LIMITED

To the Memory of

THE MASTER

ANTOINE LAURENT LAVOISIER

I dedicate this history of parts of the science which it was his glory to form from the materials gathered by himself and by many who went before him during more than two thousand years.