CONTENTS of N° 255.— Fourth Series. 



XXX. On the Spectra of Carbon. By W. M. Watts, D.Sc, 

 Physical-Science Master in the Manchester Grammar School. (With 

 a Plate.) page 249 



XXXI. On the Cause of the Phenomena of Voltaic Cooling and 

 Heating discovered by Peltier. By E. Edlund 263 



XXXII. Comparison of a Theory of the Dispersion of Light on the 

 Hypothesis of Undulations with Ditscheiner's determinations of Wave- 

 lengths and corresponding refractive Indices. By Professor Challis, 

 M.A., F.R.S., F.R.A.S 268 



XXXIII. Observations of the Corona during the Total Eclipse, 

 August 7th, 1869. By Professor Edward C. Pickering 281 



XXXIV. Investigations on the Conformity of Vapours to Mariotte 

 and Gay-Lussac's Law. By Dr. Hermann Herwig. (With a Plate.) 284 



XXXV. On the Nebular Hypothesis. By J. S. Aldis, M.A., late 

 Scholar of Trinity College, Cambridge 308 



XXXVI. Thermal Researches on the Battery. By M. P. A. Favre. 310 



XXXVII. Proceedings of Learned Societies : — 

 Royal Society: — The Earl of Rosse on the Radiation of 



Heat from the Moon 314 



Geological Society: — Mr. Hull on the Evidence of a ridge 

 of Lower Carboniferous Rocks crossing the Plain of Cheshire 

 beneath the Trias ; The Rev. T. Wiltshire on the Red Chalk 

 of Hunstanton 320-322 



XXXVIII. Intelligence and Miscellaneous Articles:— 



On the Expansion of Gases, by M. A. Cazin 322 



On the Employment of the Spectroscope in order to distinguish 



a feeble Light in a stronger one, by M. J. M. Seguin 325 



On the Mean Velocity of the Motion of Translation of the Mo- 

 lecules in Imperfect Gases, by M. P. Blaserna 326 



* It is requested that all Communications for this Work may be addressed, 

 post-paid, to the Care of Messrs. Taylor and Francis, Printing Office, Bed 

 Lion Court, Fleet Street, London. 



