518 M. Regnault on the Specific Heat of Simple Bodies. 



We may put AO=^A0, 6 representing the excess of tempe- 

 rature of the enclosure, and A^ the increase of temperature 

 which the system obtains in 1 minute. To calculate the con- 

 stant A, we might put, according to the observation from 5 to 

 10 minutes, — 



0-48 = A(98 - 77-3) = A(2007), 



whence A=g^=0-0233. 



We may calculate from this formula the elevation of tempera- 

 ture which the enclosure has given in each minute. 4 iiin •m^jm 

 From the 78th minute, when the system exceeds 100 degrees, 

 fto the 92nd minute, when it is plunged into the water of the 

 calorimeter, it loses necessarily a certain quantity of heat, in 

 consequence of its excess of temperature above the enclosure, 

 which does not exceed 100 degrees. We proceed to estimate 

 this loss of temperature from the observations of cooling, which 

 followed the molecular transformation in the experiment of 

 page 513. We shall thus obtain ^ 



temperature. Cooling. 



\m 



TAl 



.n: 



34-47 



Thus the system ought to have lost by radiation about 34°-5 

 of temperature; and the final temperature would have risen as 

 much if this loss had not taken place. But we observe that 

 34°-47 of temperature lost by the system corresponds to a num- 

 l^r of units of heat represented by 



(200-45 X 0-1036 + 7-62)34-47 = 978-6, > * 



which, added to 3851-5, which the calorimeter has given directly, 

 furnishes a total of 4830-1. 



If we subtract the 2082-1 units of heat, which we may suppose 



