Vlll CONTENTS OF VOL. XX. — FOURTH SERIES. 



Pap 



Prof. Magnus on the Conduction of Heat by Gases 510 



Mr. A. Cayley on a Relation between two Ternary Cubic Forms. 512 

 Dr. Atkinson's Chemical Notices from Foreign Journals .... 515 

 M. Fessel on the Sensitiveness of the Human Ear to the Pitch of 



Musical Notes 523 



Prof. Sylvester's Notes to the Meditation onPoncelet's Theorem. 525 

 Notices respecting New Books : — Mr. E. J. Kouth's Elementary 



Treatise on the Dynamics of a System of Rigid Bodies .... 533 

 Proceedings of the Royal Society : — 



Mr. B. Stewart on the Light radiated by heated Bodies. . 534 

 Mr. J. P. Gassiot on the Luminous Discharge of Voltaic 



Batteries, when examined in Carbonic Acid Vacua. . . . 540 

 Dr. T. Andrews and Mr. P. G. Tait on the Volumetric 

 Relations of Ozone, and the Action of the Electrical Dis- 

 charge on Oxygen and other Gases 549 



Mr. J. P. Gassiot on the Application of Electrical Dis- 

 charges from the Induction Coil to the purposes of Illu- 

 mination 550 



On the alleged practice of Arsenic-eating in Styria, by Dr. H. 



E. Roscoe 550 



On the Density of mixtures of Alcohol and Water, by M. von 



Baumhauer 552 



On the Thermal Effects of Fluids in Motion, by Dr. Joule and 



Prof. W. Thomson 552 



On the Temperature of Water in the Spheroidal State, by C. 



Marignac 553 



Index , 555 



ERRATA. 



Page 361, line 18 from bottom, a full point after the word electricity, dele 

 if, and put A for a. 



— 362, line 13 from top, for cloudy read cloudless. 



— 363, line 1 9 from bottom, for out a window read out of a window. 



PLATES. 

 Frontispiece to the Volume — Portrait of Richard Taylor, F.L.S. 



I. Illustrative of Mr. C. J. Burnett's Paper on several Forms of Actino- 



metcr. 



II. Illustrative of Professors Kirchhoff and Bunsen's Paper on Chemical 



Analysis by Spectrum-observations. 



III. Illustrative of Dr. J. II. Gladstone's Paper on the Electric Light of 



Mercury, and Mr. T. Tate's Paper on a new Self-registering Mer- 

 cury Barometer. 



IV. Illustrative of M. F. August's Paper on a new Species of Stereo- 



scopic Phenomenon, Prof. Dove's Paper on the Dichrooscope, 

 and Mr. T. Tate's Paper on the Laws of Absorption of Liquids 

 by Porous Substances. 



