﻿CONTENTS OP VOL. XLI, FOURTH SERIES. VU 



NUMBER CCLXXV.— JUNE. 



Page 



Mr, F. Guthrie on Approach caused by Vibration 405 



Parti. Dr. J. Guyot's Synthetical View of the Forms and 



Forces of Matter 406 



Part II. M. K. H. Schellbach on Acoustic Repulsion and 



Attraction 418 



Part III. Letters from Professor Sir William Thomson . . 423 

 Mr. J. K. Laughton on Barometric Differences and Fluctuations. 429 

 Prof. K. W. Zenger on the Tangent-balance, and its application 

 to determining the Density of Solids and Liquids by direct 



reading. (With a Plate.) 443 



The Hon. J. W. Strutt on the Scattering of Light by small 



Particles 447 



M. J. Quincke on the Capillary Phenomena of the common Sur- 

 face of two Liquids , 454 



Dr. A. M. Mayer on a Method of Fixing, Photographing, and 



exhibiting the Magnetic Spectra 476 



Proceedings of the Geological Society : — 



Dr. G. Grey on Fossils from Cradock and elsewhere in 



South Africa 480 



Mr. G. W. Stow on some points in South-African Geology. 480 

 Mr.C.L. Griesbach on the Geology of Natal, in South Africa. 481 

 Mr. G. Gilfillan on the Diamond-districts of the Cape of 



Good Hope 481 



On Barometric Compensation of the Pendulum, by the Astro- 

 nomer Royal 482 



On the use of the Spectral Apparatus in the Quantitative De- 

 termination of Colouring-matters, by K. Vierordt 482 



On the Zodiacal Light, by A. C. Raynard, Esq 484 



NUMBER CCLXXVI.— SUPPLEMENT. 



M. A. Heim on Glaciers. (With a Plate.) 485 



Mr. D. Vaughan on Secondary Planets in Small Orbits 508 



The Hon. J. W. Strutt on Double Refraction 519 



Mr. F. Burden on the Boiling-points of Organic Bodies 528 



Prof. Cayley on the Geodesic Lines on an Ellipsoid 534 



Notices respecting New Books : — 



Lieut. A. M. Davies on the Meteoric Theory of Saturn's 

 Rings considered with reference to the Solar Motion in 

 Space, also a paper on the Meteoric Theory of the Sun. 536 

 Proceedings of the Royal Society : — 



Sir W. Thomson's Modification of Wheatstone's Bridge to 

 find the Resistance of a Galvanometer-coil from a single 

 deflection of its own needle 537 



