PHILOSOPHICAL SOCIETY OF WASHINGTON. 91 



Mr. L. F. Ward then read a paper entitled 



ON THE ORGANIC COMPOUNDS IN THEIR RELATIONS TO LIFE. 



This paper was briefly discussed by Messrs. Antisell and 

 Elliott, after which the Society adjourned. 



211th Meeting. February 11, 1882. 



President Wm. B. Taylor in the chair. 



Mr. Gilbert presented to the Society a communication 



on errors of barometric observations produced by wind. 



This communication will be published in full in the Report of 

 the Geological Survey. 



This communication was discussed by Messrs. Baker, Mason, 

 and A.NTISELL, after which the Society adjourned. 



212th Meeting. February 25, 1882. 



President Wm. B. Taylor in the chair. 

 Thirty members and visitors present. 



Mr. Ferrel presented to the Society the concluding portion of a 

 communication offered to the Society at its 210th meeting, January 

 28 th, 



on the conditions determining temperature. 



The usual formula for the rate of cooling of a heated body in 

 vacuo, first given by Pouillet as determined from the experiments 

 of Dulong and Petit, is of the form : 



dh = Bfj? — pS ) 

 In which 



B = the units of heat radiated by a unit of lamp-black surface in 



a unit of time ; 

 f = the radiating power of the body, lamp-black being unity ; 

 t = the temperature of the cooling body ; 

 t' = the temperature of the enclosure ; 

 ix = a constant, of which the value is 1.0077 ; 

 Sh = the heat lost in a unit of time for each unit of surface. 



