﻿CONTENTS of N° 215.— Fourth Series. 



LV. On Approach caused by Vibration. By various Authors. 



Edited by Frederick Guthrie page 405 



Part I. Synthetical View of the Forms and Forces of Matter. 



By Dr. Jules Guyot 406 



Part II. Acoustic Repulsion and Attraction. By K. H. Schell- 



bach 418 



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



LVI. On Barometric Differences and Fluctuations. By John 

 Knox Laughton, M.A., F.R.A.S., F.R.G.S., Mathematical and 

 Naval Instructor at the Royal Naval College, Portsmouth 429 



LVII. On the Tangent-balance, and its application to determining 

 the Density of Solids and Liquids by direct reading. By Professor K. 

 W. Zenger. (With a Plate.) 443 



LVIII. On the Scattering of Light by small Particles. By the 

 Hon. J. W. Strutt, Fellow of Trinity College, Cambridge 447 



LIX. On the Capillary Phenomena of the common Surface of two 

 Liquids. By G. Quincke 454 



LX. On a Method of Fixing, Photographing, and exhibiting the 

 Magnetic Spectra. By Alfred M. Mayer, Ph.D 476 



LXI. Proceedings of Learned Societies : — • 



Geological Society: — Dr. G. Grey on Fossils from Cradock 

 and elsewhere in South Africa ; Mr. G. W. Stow on some 

 points in South-African Geology ; Mr. C. L. Griesbach on the 

 Geology of Natal, in South Africa ; Mr. G. Gilfillan on the 

 Diamond-districts of the Cape of Good Hope , 480-481 



LXII. Intelligence and Miscellaneous Articles : — 



On Barometric Compensation of the Pendulum, by the Astro- 

 nomer Royal 482 



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

 mination of Colouring-matters, by K. Vierordt 482 



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



*** It is requested that all Communications for this Work may be addressed, 



£ost-paid, to the Care of Messrs. Taylor and Francis, Printing Office, Red 

 <ion Court, Fleet Street, London. 



