vi CONTENTS OF VOL. XXIII. 



Page 



Mr. T. Everitt od the Leaf-stalks of Garden Rhubarb as a 



Source of Malic Acid 327 



Dr. Stenhouse's Examination of Astringent Substances 331 



Mr. J. W. Stubbs on the application of a new Method to the 



Geometry of Curves and Curve Surfaces 338 



Mr. Joule on the Calorific Effects of Magneto-Electricity, and 



on the Mechanical Value of Heat (continued) 347 



Prof. Ludwig Moser on the so-called Calorotypes, with Ani-.^^y 

 madversions on the Papers of Mr. Hunt and Prof. Draper 



lately published in the Philosophical Magazine 356 



Sir W. R. Hamilton on an Expression for the Numbers of Ber- 

 noulli, by means of a Definite Integral ; and on some con- 

 nected Processes of Summation and Integration 360 



Mr. E. Solly's Note on the Changes in Colour exhibited by So- 

 lutions of Chloride of Copper 367 



Proceedings of the Royal Society 368 



Chemical Society 385 



On a Change produced by Exposure to the Beams of the Sun, 

 in the Properties of an Elementary Substance, by Prof. Dra- 

 per, of New York 388 



Account of Clegg's Differential Dry Gas-light Meter, by Prof. 



Vignoles, C.E. ' 388 



Action of Sulphurous Acid on Metallic Oxides 397 



Extraction of Palladium in Brazil 398 



On the Influence of Temperature on the Production of Iodo- 

 form, by M. Bouchardat 398 



Meteorological Observations for September 1843 .... ..... 399 



Table 400 



NUMBER CUV.— DECEMBER. 



Dr. Draper's Description of the Tithonometer, an instrument 

 for measuring the Chemical Force of the Indigo-tithonic 

 Rays 401 



Mr. R. Hunt on the Spectral Images of M. Moser ; a Reply 

 to his Animadversions, &c 415 



Dr. Stenhouse on Theine and its Preparation 426 



Mr. Joule on the Calorific Effects of Magneto-Electricity, and 

 on the Mechanical Value of Heat (concluded) 435 



Professor Grove's Experiments on Voltaic Reaction 443 



The Rev. W. Bruce's Occasional Notes on Indications of the 

 Barometer and Thermometer during Stormy Weather at 

 Belfast, from November 1833 to January 1843 446 



Prof. J. It. Young's New Criteria for the Imaginary Roots of 

 Numerical Equations 450 



