Aurora and Planets Venus and Jupiter: pp. 66, 67. Aurora and Zodiacal Light: pp. 67-69. CHAPTER VII. Aurora-like patches on the partially-eclipsed Moon: pp. 70-77. CHAPTER VIII. Aurora and Solar Corona: pp. 78-81. CHAPTER IX. Supposed Causes of the Aurora: pp. 82-87. Prof. Lemström’s Theory: pp. 87, 88. Theories of MM. Becquerel and De la Rive: p. 88. M. Planté’s electric experiments: pp. 89, 90. PART II. THE SPECTRUM OF THE AURORA. CHAPTER X. Spectroscope adapted for the Aurora: pp. 91-93. Spectrum of Aurora described: pp. 94-100. Flickering of the green line: p. 100. Mr. Backhouse’s graphical spectra of four Auroræ: p. 101. Lord Lindsay’s Aurora-spectrum, October 21, 1870: p. 102. Spectrum of the Aurora Australis: pp. 103, 104. Professor Piazzi Smyth’s Aurora-spectra: p. 104. Author’s Catalogue of the Auroral lines: pp. 104-106. Theories in relation to the Aurora and its spectrum: pp. 106, 107. CHAPTER XI. The comparison of some Tube and other Spectra with the Spectrum of the Aurora: pp. 108-120. Hydrogen-tube: pp. 108-110. Carbon- and oxygen-tubes: pp. 110-114. Geissler mercury-tube and barometer mercurial vacuum: pp. 114, 115. Air-tubes: pp. 115, 116. Phosphorescent tube: pp. 116, 117. Spark in air: p. 117. Spark over water: p. 117. Phosphoretted-hydrogen flame: pp. 117, 118. Iron-spectrum: p. 118. Spectrum of mercury: p. 119. Table of coincidences: p. 119. CHAPTER XII. Notes on Professor Ångström’s Theory of the Aurora-spectrum: pp. 121-127. CHAPTER XIII. The Oxygen-spectrum in relation to the Aurora (Procter and Schuster): pp. 128-131. PART III. MAGNETO-ELECTRIC EXPERIMENTS IN CONNEXION WITH THE AURORA. INTRODUCTION: pp. 133-135. CHAPTER XIV. Examination of Geissler-tubes under action of the Magnet: pp. 136-146. Nitrogen-tubes: pp. 136, 137. Oxygen-tubes: p. 138. Hydrogen-tubes: pp. 138, 139. Water-gas tube: p. 139. Ammonia-tube: pp. 139, 140. Carbonic-acid tube: p. 140. Chlorine-tubes: pp. 140, 141. Iodine-tubes: pp. 141-143. Bromine-tubes: pp. 143, 144. Silicic fluoride-tubes: p. 144. Sulphuric-acid tubes: pp. 144, 145. Sulphur-tube: pp. 145, 146. CHAPTER XV. Effect of Magnet on a capillary Glass Tube: pp. 147, 148. Action of magnet on a bar of heavy glass: pp. 147, 148. CHAPTER XVI.