CONTENTS OF VOL. XXXVII 



(THIRD SERIES.) 



NUMBER CCXLVIL— JULY 1850. 



Page 

 Messrs. J. Tyndall and H. Knoblauch's Second Memoir on the 

 Magneto-optic Properties of Crystals, and the relation of Mag- 

 netism and Diamagnetism to Molecular Arrangement 1 



Mr. J. Bryce's Notices of a late Visit to the Parallel Roads of 



Lochaber 33 



Dr. Buys Ballot on the great importance of Deviations from the 

 mean state of the Atmosphere for the Science of Meteor- 

 ology 42 



Mr. A. Cayley on the Triadic Arrangements of Seven and Fif- 

 teen Things 50 



Prof. W. Thomson on some remarkable effects of Lightning, 

 observed in a Farm-house near Moniemail, near Cupar- Fife 53 



Proceedings of the Royal Society 57 



Cambridge Philosophical Society 68 



• Royal Astronomical Society 69 



— ■ British Meteorological Society 71 



The Lagoons of Tuscany 72 



On the Interpretation of Mariotte's Law, by Lieut. E. B. Hunt, 



U.S. Corps of Engineers 76 



Effects of Atmospheric Electricity upon the Wires of the Mag- 

 netic Telegraph 78 



Meteorological Observations for May 1850 79 



Meteorological Observations made by Mr. Thompson at the 

 Garden of the Horticultural Society at Chiswick, near 

 London ; by Mr. Veall at Boston ; by the Rev. W. Dunbar at 

 Applegarth Manse, Dumfries -shire ; and by the Rev. C. 

 Clouston at Sandwick Manse, Orkney 80 



NUMBER CCXLVIIL— AUGUST. 



Prof. Potter on the Aerometric Balance, an instrument for mea- 

 suring the Density of the Air in which it is situated 81 



a2 



