IV CONTENTS OF VOL. XLIII. FIFTH SERIES. 



NUMBEE CCLXL— FEBRUARY. 



Page 

 Messrs. John Trowbridge and T. "W. Richards on the Spectra 



of Argon , 77 



Mr. W. Sutherland on Two New Pressure-Gauges for the 



Highest Vacua 83 



Prof. J. G. MacGregor on the Eelation of the Physical 



Properties of Aqueous Solutions to their State of Ionization. 99 

 Mr. W. Barlow on the Eelation of Circular Polarization, as 

 occurring both in the Amorphous and Crystalline States, to 

 the Symmetry and Partitioning of Homogeneous Structures, 



i. e. of Crystals 110 



Dr. G. A. Miller on the Transitive Substitution Groups of 



Order 8p, p being any Prime Number 117 



Lord Rayleigh on the Passage of Electric Waves through 



Tubes, or the Vibrations of Dielectric Cylinders 125 



Angelo Battelli on Photographic Action inside Discharge 



Tubes 133 



Messrs. J. Trowbridge and T. W. Eichards on the Multiple 



Spectra of Gases 135 



Dr. G. J. Stoney on the Generality of a New Theorem .... 139 

 Prof. Osborne Eeynolds on Thermal Transpiration and 



Eadiometer Motion 142 



Notices respecting New Books :— 



Eranz Kerntler's Die elektrodynamischen Grundgesetze 



und das eigentliche Elementargesetz 149 



Prof. W. E. Ayrton's Practical Electricity — A Laboratory 

 and Lecture Course for Eirst Tear Students of 



Electrical Engineering. Yol. 1 149 



Proceedings of the Geological Society : — 



Prof. E. Hull on Another possible Cause of the Glacial 



Epoch 150 



On the Explosion of Thin Layers of Explosive Gases, by 



Prof. E. Emich 151 



The Bres«a Prize 152 



NUMBER CCLXIL— MAECH. 



Sir H. E. Eoscoe and Mr. A. Harden on the Genesis of 

 Dalton's Atomic Theory 153 



Drs. A. C. Crehore and G. O. Squier: Discussion of the 

 Currents in the Branches of a "Wheatst one's Bridge, where 

 each Branch contains Eesistance and Inductance, and there 

 is an harmonic impressed electromotive force 161 



Dr. C. Chree on Applications of Physics and Mathematics to 

 Seismology 173 



