CONTENTS. Hi 



Company, to Dr Richardson. Communicated 

 by the latter, .... 123 



XII. Register of the Temperature of the Atmosphere 

 kept at Fort Simpson, North America, in the 

 years 1837, 1838, 1839, and 1840. By Mur- 

 doch M c Pherson, Esq., Chief Trader of the 

 Hudson's Bay Company ; abstracted by John 

 Richardson, M. D., F.R.S., Inspector of Na- 

 val Hospitals, Harlar, . . .124 



XIII. Physical and Chemical Examination of Three In- 



flammable Gases which are evolved in Coal- 

 mines. By Dr Gustav Bischof, Professor of 

 Chemistry in the University of Bonn. Commu- 

 nicated by the Author. Concluded from vol. 

 xxix. p. 333, . . . .127 



§ 9. Analysis of Pit-gas in the Detonation Tube, 127 

 § 10. Analysis of Pit-gas by Oxide of Copper, 134 



§ 11. Determination of the Specific Gravity of the 



Pit-gas, . . . . 135 



Chemical Analysis of the Pit-gas of Gerhard's Stol- 



len, 139 



Physical and Chemical Examination of an Inflam- 

 mable Gas which is evolved from an Artesian 

 well in the Principality of Schaumburg, . 146 



Experiments to determine the limits of the Inflam- 

 mability of the Inflammable Pit-Gases mixed 

 with Atmospheric Air, . . .149 



Principal Results of the previous Investigations, 151 



XIV. Observations on Recent Earthquakes on the West 



Coast of South America. By Mathie Hamil- 

 ton, Esq., formerly Surgeon to the Potosi, Paz, 

 and Peruvian Mining Company, &c. Commu- 

 nicated by the Author, . . .153 



XV. Observations on the Glaciers of Spitzbergen, com- 

 pared with those of Switzerland and Norway. 

 By C. Martens, M D., Member of the Northern 

 Commission, . . . .160 



XVI. Description of the process of Daguerreotype, and 

 Remarks on the Action of Light in that pro- 

 cess, both in respect to Landscape and Minia- 

 ture Portraits. By Mr Thomas Davidson, 



