CONTENTS OF VOL. XXXVL 



(THIRD SERIES.) 



NUMBER CCXL.— JANUARY 1850. 



Page 



Dr. Percy's Experiments on the Extraction of Gold and Silver 



from their Ores by the Wet Way 1 



Mr.T. Weddle on Annuities and Assurances on Successive Lives 8 

 Prof. Potter on the supposed Inversion of Hydrostatical Prin- 

 ciples Vi'hich takes place in the casting of Specula for Reflecting 

 Telescopes on a " chilling " base formed of hoop-iron packed 



edgewise 13 



Mr. J. R. Young on a property of the Interminable Decimals 

 which arise from the Development of an Incommensurable 



Fraction 15 



Mineralogical Notices : — 



M. Rammelsberg on Schorlamite 21 



M. Rammelsberg on Chlorite 22 



MM. Breithaupt and Plattner on Glaukodote 23 



MM. Breithaupt and Plattner on Embolite 23 



M. Breithaupt on Lonchidite 24 



MM. Breithaupt and Fritzsche on Konichalcite 24 



M. Breithaupt on the occurrence of Arsenic in Iron Pyrites 25 



M. Giwartowski on Glaucolite 25 



M. Rammelsberg on Arkansite and Brookite 25 



L. A. Jordan on Smectite 27 



M. J. Antoine on the Multiple Sounds and Optical Phaenomena 



produced by Vibrating Bodies. Theory of the Bow 27 



Notices respecting New Books: — M. Regnault's Relation des 

 Experiences pour determiner les principales lois physiques, et 

 les donnees numeriques qui entrent dans le Calcul des Ma- 

 chines k Vapeur 41 



New Process for extracting Sugar from the Sugar-Cane, by M. 



Melsens 62 



Mr. S. M. Drach's Thermometric Scale 65 



Action of Hydrochloric Acid on the Hydrates of Oil of Turpen- 

 tine, by M. H. Deville 66 



a2 



V 



