Chapter Iv.--Physical Theories of Heat.

Thermotical Theories. 181 Atmological Theories. 184 Conclusion. 187

THE MECHANICO-CHEMICAL SCIENCES.

BOOK XI.

HISTORY OF ELECTRICITY.

Introduction. 191

CHAPTER I.--DISCOVERY OF LAWS OF ELECTRIC PHENOMENA. 193

CHAPTER II.--THE PROGRESS OF ELECTRICAL THEORY. 201

Question of One or Two Fluids. 210 Question of the Material Reality of the Electric Fluid. 212 {11}