Downfall of phlogistonism. Lavoisier: his life and work. His death. _Le principe oxygine._ Principle of the conservation of matter. Chemistry a science of quantitative relations. Prominent anti-phlogistians. Berthollet. The _Statique Chimique_. Fourcroy. Vauquelin. Klaproth. Proust. CHAPTER IX THE ATOMIC THEORY 123 The atomic hypotheses of the ancients. Newton. Bergmann. Lavoisier. Richter. Stochiometry. John Dalton: sketch of his life and character. How he was led to his explanation of the laws of chemical combination. The _New System of Chemical Philosophy_. Reception of his theory by Davy and Wollaston. Berzelius: his life and work. His services to chemistry. First accurate series of atomic weight determinations. Avogadro. Prout’s hypothesis. CHAPTER X THE BEGINNINGS OF ELECTRO-CHEMISTRY 140 The Voltaic Pile. Electrolytic decomposition of water by Nicholson and Carlisle. Application of voltaic electricity to the decomposition of the alkalis by Davy. His life and work. Wollaston: his life and work. Electro-chemical system of Berzelius. Dualism. Berzelius reforms chemical notation and nomenclature. Gay Lussac: his life and work. Thénard: his life and work. Faraday and the law of definite electrolytic action. CHAPTER XI THE FOUNDATIONS OF ORGANIC CHEMISTRY 154 Nicolas Lemery divides chemistry into its two main branches of inorganic and organic chemistry. State of knowledge of products of organic origin during the early years of the nineteenth century. Animal chemistry. Doctrine of vital force. Wöhler’s synthesis of urea. Organic chemistry is the chemistry of the carbon compounds. Early attempts at organic analysis by Lavoisier, Berzelius, Gay Lussac, and Thénard. Liebig. Discovery of _isomerism_ and _allotropy_. Cyanogen. Theory of compound radicals. Etherin theory of Dumas and Boullay. Memoir of Liebig and Wöhler on oil of bitter almonds. Benzoyl theory. Investigation of alkarsin by Bunsen. Cacodyl. Discovery of zinc ethyl by Frankland. CHAPTER XII THE RISE OF PHYSICAL CHEMISTRY 170