CONTENTS or VOL. I. FOURTH SERIES. Vll 



Page 

 Polarization by Caoutchouc and Gutta Percha, by Prof. Chas. 



G. Page, M.D 262 



Meteorological Observations for January 1851 263 



Table 264 



NUMBER IV.— APRIL, 



Dr. Tyndall on the Laws of Magnetism 265 



Mr. J. J. Sylvester on the Relation between the Minor Deter- 

 minants of Linearly Equivalent Quadratic Functions 295 



Prof. Stokes's Examination of the possible effect of the Radia- 

 tion of Heat on the Propagation of Sound 305 



Prof. Potter's Reply to the Observations of Mr. Rankine in the 



last Number of the Magazine 317 



Prof. Potter on the Solution of the Problem of Sound transmitted 



through Liquids 319 



Mr. T. S. Hunt's Examinations of some Canadian Minerals . . 322 



M. Quetelet on Atmospheric Electricity, especially in 1849 . . 329 

 The Rev. S. Haughton's Remarks on Professor Potter's Theory 



of Sound 332 



M. Ed. Desains on the Polarization of Light reflected by Glass 335 



Proceedings of the Cambridge Philosophical Society 336 



Royal Society 339 



On the Sulphuret of Nitrogen, by MM. Fordos and Gelis 346 



On the Cyanic Amidides, by Messrs. L. Cloez and Cannizzaro 349 



On the Occurrence of Gadolinite in Ireland, by J. W. Mallet. . 350 



Meteorological Observations for February 1851 351 



Table 352 



NUMBER v.— MAY. 



Prof. Donkin on certain Questions relating to the Theory of 

 Probabilities 353 



Prof. Draper on the Chemical Action of Light 368 



Prof. Stokes on the Principles of Hydrodynamics, in Reply to 

 Prof. Challis 393 



Prof. O'Brien on the Interpretation of the Product of a Line and 

 a Force 394 



M. R. Clausius on the Deportment of Vapour during its Expan- 

 sion under different circumstances 398 



Prof. Challis on the Theory of the Velocity of Sound 405 



Prof. Potter's Reply to the Objections advanced against the 

 paper on Sound in the February Number 408 



Mr. W, J. M. Rankine on Poisson's investigation of the Theory 

 of Sound 410 



Mineralogical Notices 411 



