CONTENTS OF VOL. XIII. FIFTH SERIES. VII 



NUMBER LXXXIIL— JUNE. 



Page 



Prof. R. Clausius on the different Systems of Measures for 

 Electric and Magnetic Quantities 381 



Mr. S. H. Ereeinan on the Question of Electrification by Eva- 

 poration 398 



Prof. Silvanus P. Thompson on the Function of the two Ears 

 in the Perception of Space 406 



Mr. S. H. Burbuiy on a Theorem on the Dissipation of Energy. 417 



Mr. J. J. Hood on Retardation of Chemical Action 419 



Prof. J. A. Ewing on the supposed Helical Path of the Elec- 

 tric Current in longitudinally Magnetized Conductors .... 423 



Mr. J. J. Thomson on the Dimensions of a Magnetic Pole in 

 the Electrostatic System of Units 427 



Prof. J. Larmor on the Electrostatic Dimensions of a Magnetic 

 Pole 429 



Prof. J. D. Everett on the Dimensions of a Magnetic Pole in 

 the Electrostatic System of Units. (Second Article.) .... 431 



Prof. J. Tyndall on the Action of Eree Molecules on Radiant 

 Heat, and its Conversion thereby into Sound 435 



Notices respecting New Books : — 



Kant's Critique of Pure Reason 462 



Mr. R. P. Wright's Lessons on Eorm 466 



On the Liquefaction of Ozone, by P. Hautefeuille and J. 

 Chappuis 467 



On the Action of Telephonic Currents upon the Galvanometer, 

 by M. de Chardonnet « 468 



NUMBER LXXXIV.— SUPPLEMENT. 

 Prof. H. A. Rowland on the Results accomplished in the Ma- 

 nufacture and Theory of Gratings for Optical purposes . . 469 



Mr. L. Eletcher's Crystallograpbic Notes. (Plate X.) 474 



Prof. J. Tyndall on the Action of Eree Molecules on Radiant 



Heat, and its Conversion thereby into Sound 480 



Mr. W. G. Lettsom on Rhabdophane, a new Mineral 527 



Mr. W. G. Lettsom on the Dichroism of two European Anda- 



lusites 529 



Mr. C. K. Wead on the Dimensions of a Magnetic Pole in the 



Electrostatic System of Units 530 



Notices respecting New Books : — 



Dr. R. Wormell's Magnetism and Electricity 534 



The Calendar of the Departments of Law, Science, and 

 Literature of the Tokio Dai-Gaku (University of Tokio), 



1880-81 535 



On the Effects produced in a Vacuum by the Current of the 



Gramme Machines, by MM. Jamin and G. Maneuvrier . . 536 

 On the Employment of Rotating Disks for the Study of 

 Coloured Sensations — the Relative Intensity of Colours, by 

 A. Rosenstiehl 538 



