CONTENTS. 



Art. I. On Volcanos and Craters of Elevation. By Leopold 



Von Buch, - - - Page 189 



n. On the Temperature- of the Earth's Surface during 

 the Tertiary Period. By M. Elib de Beau- 

 mont, - . - - 206 



:' :iin. Account of one of the most important Results of the 

 Investigations of M. Vbnetz, regarding the Pre- 

 sent and Earlier Condition of the Glaciers of the 

 Canton Vallais. By Johann von Charpenjier. 

 With later additions by the Author, - 210 



IV. Memoir on the Metamorphoses in the Macrourae or 



Long-tailed Crustacea, exemplified in the Prawn 

 (Palaemon serratus). By W. V. Thompson, Esq., 

 F. L. S., Deputy Inspector- General of Hospitals. 

 (Communicated by Sir James MacGrigor, Bart., 

 M.D., F.R.S., &c., - - - 221 



V. Considerations respecting a New Power which acts in 



the Formation of Organic Bodies. By M. Bbr- 

 ZELius, - - - - 223 



.,yi. Account of a Method of separating Small Quantities 

 of Arsenic from Substances with which it may be 

 mixed. By James Marsh, Esq. of the Royal 

 Arsenal, Woolwich. (Communicated to the So- 

 ciety of Arts of London), - - 229 



