Vlll CONTEXTS OF VOL. I. -FOURTH SERIES. 



Page 



Mr. J, Cockle on the Solution of Three Simultaneous Quadratics 



of the Fifth Order 413 



Mr. J. J. Sylvester on Quadratic Functions and Hyperdeter- 



minants "415 



Notices respecting New Books : — M. I'Abbe Moigno on French 

 claims to the Invention of the Principle of Construction em- 

 ployed in the Conway and Menai Bridges 416 



Proceedings of the Royal Society 420 



Royal Institution 428 



On the Phosphorescence of Chalk Streaks 432 



Observations on Nitrous Acid and the Solution of Nitro-sul- 



phuric Acid, by M.Guinon 432 



On the Composition of some Corallines, by M. Damour 434 



On Sulphuret of Nitrogen, by MM. Fordos and Gelis 435 



Corrections in Mr. Drach's paper, March 1 85 1 437 



On Photography, by W. R. Deere Salmon 437 



Government Manufacture and Publication of School Books . . 438 



Meteorological Observations for March 1851 439 



Table 440 



NUMBER VI.— JUNE. 



Mr. W. J. M. Rankine on the Vibrations of Plane-Polarized 

 Light 441 



Prof, Pliicker and Dr. Beer on the Magnetic Axes of Crystals, 

 and their relation to Crystalline Form and to the Optic Axes 447 



Prof. Donkin on certain Questions relating to the Theory of 

 Probabilities. Part II 458 



MM. De la Provostaye and Desainson the Rotary Power which 

 the Essence of Turpentine and Saccharine Solutions exercise 

 on Heat 466 



Prof. Thomson on the Effect of Fluid Friction in drying Steam 

 which issues from a High-pressure Boiler through a small 

 Orifice into the open Air . ; 474 



Prof. Potter's Reply to Remarks connected with the Solution 

 of the Problem of Sound 475 



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

 Professor Stokes 477 



M. A. F. J. Claudet on the Dynactinometer, an Instrument for 

 measuring the Intensity of the Photogenic Rays and com- 

 paring the Power of Object-Glasses ; with Observations on 

 the difference between the Visual and Photogenic Foci, and 

 their constant variation. (With a Plate.) 478 



Prof. O'Brien on Symbolical Statics .... 491 



M. E. F. August on the Rotation caused by Electricity deve- 

 loped by Friction 495 



Notices respecting New Books : — Dr. Daubeny's Introduction 

 to the Atomic Theory 496 



