110 Dr. W. F. Hillebrand on the Specific Heats 







I. 



II. 



1-8425 



99°-804 

 80' 



013 

 0-233 

 522-2 

 53672 





t 



Mi-Mo 



±o 

 m 



II 



m x 



Qo-Qx 



T 



1-3287 



S9°-89 



90' 



016 



014 

 3717 



385-2 





Duration of the experiments 



Scale-variation before experiment . . . 



Scale-variation after experiment . . . 



Keduced and corrected retraction ... 



Wg from Exp. I. . 

 W^ from Exp. II. . 



W mean . . . 



= 2-902 

 = 2-919 



2-9105 



In order to calculate the specific heat S of the metals, the 

 formula* 



T 



$ = 



7-(WA+TO 



(i) 



is used, in which 



G g = weight of the glass envelope, 



G m — weight of metal employed, 



Q l = weight of air enclosed with the metal in the glass en- 

 velope. 



No special estimations of W w were needed, since the ice- 

 calorimeter employed was the same as that which Professor 

 Bunsen had already made use of, and for which he had deter- 

 mined 



W w = 14-657. 



W/= the. amount of heat expressed in scale-divisions which 

 1 grm. of atmospheric air gives out in cooling from 1° C. to 

 0° C. This amount of heat is given by means of the equation 



w,=w«s„ 



in which S* denotes the specific heat of the air at constant 

 volume. By putting 8^=0*1668, we have 



W,= 2-445. 



In order to estimate G h the external volume V of the sealed 

 envelope containing the metal was estimated in cubic centi- 

 metres by immersing it in a measuring cylinder containing 

 water. Calling the weight of the glass envelope G , 



its specific gravity s ; 



* Pogg. Ann. vol. cxli. p. 23. 



