Of Specific Heat. --Of the different Capacities of Bodies for Heat. --Specific Heat not perceptible by the Senses. --How to be ascertained. --Of Latent Heat. --Distinction between Latent and Specific Heat. --Phenomena attending the Melting of Ice and the Formation of Vapour. --Phenomena attending the Formation of Ice, and the Condensation of Elastic Fluids. --Instances of Condensation, and consequent Disengagement of Heat, produced by Mixtures, by the Slaking of Lime. --General Remarks on Latent Heat. --Explanation of the Phenomena of Ether boiling, and Water freezing, at the same Temperature. --Of the Production of Cold by Evaporation. --Calorimeter. --Meteorological Remarks. CONVERSATION V. ON THE CHEMICAL AGENCIES OF ELECTRICITY. 160 Of Positive and Negative Electricity. --Galvani’s Discoveries. --Voltaic Battery. --Electrical Machine. --Theory of Voltaic Excitement. CONVERSATION VI. ON OXYGEN AND NITROGEN. 181 The Atmosphere composed of Oxygen and Nitrogen in the State of Gas. --Definition of Gas. --Distinction between Gas and Vapour. --Oxygen essential to Combustion and Respiration. --Decomposition of the Atmosphere by Combustion. --Nitrogen Gas obtained by this Process. --Of Oxygenation in general. --Of the Oxydation of Metals. --Oxygen Gas obtained from Oxyd of Manganese. --Description of a Water-Bath for collecting and preserving Gases. --Combustion of Iron Wire in Oxygen Gas. --Fixed and volatile Products of Combustion. --Patent Lamps. --Decomposition of the Atmosphere by Respiration. --Recomposition of the Atmosphere. CONVERSATION VII. ON HYDROGEN. 214 Of Hydrogen. --Of the Formation of Water by the Combustion of Hydrogen. --Of the Decomposition of Water. --Detonation of Hydrogen Gas. --Description of Lavoisier’s Apparatus for the formation of Water. --Hydrogen Gas essential to the Production of Flame. --Musical Tones produced by the Combustion of Hydrogen Gas within a Glass Tube. --Combustion of Candles explained. --Gas lights. --Detonation of Hydrogen Gas in Soap Bubbles. --Air Balloons. --Meteorological Phenomena ascribed to Hydrogen Gas. --Miner’s Lamp. [Transcriber’s Note: The final two pages of the Table of Contents for Volume I were missing; everything after “Decomposition of Water” was supplied from earlier and later editions, compared against the body text. The section marked “Diamond” (Conv. IX) was called “Diamond is Carbon(e) in a state of perfect purity” in the 4th edn., “Diamond” alone in later editions.] CONVERSATION VIII. ON SULPHUR AND PHOSPHORUS. 256