CONTENTS OF VOL. XVI. 
(FIFTH SERIES). 
NUMBER XC VII.— JULY 1883. 
Page 
Prof. G-. Quincke on the Constant of Dielectricity and the 
Double .Refraction of Insulating Fluids 1 
Dr. A. 3. Leeds on a Puoto-cheinical Method for the Deter- 
mination of Organic Matter in Potable Water 9 
Mr. D. D. Heath on Mr. Ferrel's Theory of Atmospheric 
Currents 13 
Mr. J. Monro on Metal Microphones in vacuo 23 
Dr. C. R. A. Wright on the Determination of Chemical Affinity 
in terms of Electromotive Force. — Part VII 25 
Dr. J. A. Fleming on a Phenomenon of Molecular Radiation 
in Incandescence Lamps. 48 
Lord Bayieigh on the Crispations of Fluid resting upon a 
Vibrating Support 50 
Mr. W. Baiiy's Illustration of the Crossing of Bays. (Plate I.) 58 
Sir William Siemens on the Conservation of Solar Energy . . 62 
Notices respecting New Books : — 
Dr. J. Veitch's Sir William Hamilton : the Man and his 
Philosophy 66 
Mr. A. Gr. G-reenhill's Motion of a Projectile in a Besist- 
ing Medium 6Q 
Proceedings of the Geological Society : — 
Dr. C. Callaway on the Age of the newer Gneissic Bocks 
of the Northern Highlands 67 
Mr. C. J. Woodward on a Croup of Minerals from Lille- 
shall, Salop 68 
Prof. J. W. Judd and Mr. Gf. A. J. Cole on the Basalt- 
glass (Tachylyte) of the Western Isles of Scotland .... 69 
Prof. T. Gh Bonney on a Section recently exposed in Baron 
Hill Park near Beaumaris, and on the Bocks between 
the Quartz Felsite and the Cambrian Series in the 
neighbourhood of Bangor 69, 70 
