TABLE OF CONTENTS. 



NUMBER I.— JULY. 



Page 

 M. Rudberg on the Refraction of the differently-coloured 

 Rays in Crystals with one and two Axes of Double Refrac- 

 tion (continued) • ^ 



Sir D. Brewster's Observations on the preceding Memoir 6 



Mr. J. E. Drinkwater on the Invention of the Telescope 9 



On the Encouragement of Science by the King of Denmark. . 16 

 Mr. P. Barlow's Additional Experiments on the Strength and 



Stiffness of Acacia 1 ' 



Sir D. Brewster on a new Species of Coloured Fringes pro- 

 duced by Refraction between the Lenses of Achromatic or 



Compound Object-Glasses 19 



Mr. J. Blackwall's Remarks on the Diving of Aquatic Birds . . 23 

 Addition to the Analytical Investigation of a Formula for the 

 Relative Importance of the Boroughs. And Reply to Dr. 



M'Intyres Remarks • 26 



Mr. W. Sturgeon on the Distribution of Magnetic Polarity in 



Metallic Bodies 31 



Rev. J. Challis on the Resistance to the Motion of small Sphe- 

 rical Bodies in elastic Mediums ^0 



Signor Salvatore Dal Negro's New Experiments relative to 

 the Action of Magnetism on Electro-dynamic Spirals, and a 

 Description of a new Electro-motive Battery; with notes by 



M. Faraday, Esq. F.R S • 45 



Mr. J. D. Forbes's Account of some Experiments in which an 



Electric Spark was elicited from a natural Magnet 49 



Mr. B. Bevan's Remarks on Mr. White's Experiments on the 



Cohesion of Cements; with a tabular View of their Results 53 

 Mr. R. Potter's Addendum to the Paper on a Method for 

 giving the Figures of the Conic Sections to Concave Lenses 



and Specula J5 



Mr. R. Potter's Experiments to determine the Reflection at 

 the second Surface of Flint-Glass at Incidences at which 



no Portion of the Rays passes through the Surface 56 



Sir J. F. W. Herschel on the Action of Light in determining 



the precipitation of Muriate of Platinum by Lime-water 60 



Proceedings of the Royal Society 60 



Linnaean Society 70 



at the Friday-Evening Meetings of the Royal 



Institution of Great Britain 72 



of the Cambridge Philosophical Society 75 



«_- , British Association for the Advancement 



of Science • 77 



a 2 



