U CONTENTS. 



Page 



Experimental Illustration of the Equality between the Radiating and 

 Absorbing Powers of the same Surface. By the Rev. WIL- 

 LIAM RITCHIE, M.A. F.R.S., Prof, of Nat. and Exper. Philos., 

 Royal Institution .... 305 



On the Penetrativeness of Fluids. By J. K. MITCHELL, M.D., 

 Lecturer on Medical Chemistry in the Philadelphia Medical 

 Institute ..... 307 



ANALYSIS OF BOOKS. 



Memoir of the Life of Thomas Young, M.D. F.R.S., Foreign Asso- 

 ciate of the Royal Institute of France, &c., &c. . 322 



PROCEEDINGS OF THE ACADEMY OF SCIENCES AT PARIS. 



Agricultural and Rural Economy . . . 335 



Botany . . . . . .337 



Chemistry ..... 367 



Geology ...... 371 



Medical Science . . . . . 375 



Natural Philosophy . . . .377 



Zoology ...... 378 



Miscellaneous . , . 383 



FOREIGN AND MISCELLANEOUS INTELLIGENCE. 

 I. MECHANICAL SCIENCE. 



1 . On the Flexure and Force of certain Woods . . 392 



2. Double Images of Objects seen through the Air . . ibid. 



II. CHEMICAL SCIENCE. 



1. On the Rapid Production of Steam by heated Metals . . 393 



2. Discharge of Lightning over a large Surface . . . 395 



3. Becquerel on the Electric Effects produced by Heat and Pressure ; . 396 



4. Crystallization of Perchloric Acid (Serullas) ... 397 



5. Strength Test for Bleaching Powder . . . .398 



