SPECIFIC INDUCTIVE CAPACITY OF SHELL-LAC. 29 



that case the air would have lost 170°, and communicated only 1 13° to the shell-lac ; 

 and the relative specific capacity of the latter would appear to be 1*50, which is very 

 little indeed removed from 1*47, the expression given by the second experiment when 

 corrected in the same way. 



1264. The shell-lac was then removed from app. i. and put into app. ii. and the 

 experiments of division again made. I give the results, because I think the import- 

 ance of the point justifies and even requires them. 



App. i. Air. App. ii. Lac. 



Balls 200°. 

 .... 0° 

 286° .... 

 283 ... . 

 Charge divided. 

 .... 110 

 109 ... . 



. . . . 0"25 after discliarge. 

 Trace .... after discharge. 



Here app. i. retained 109°, having lost 174° in communicating 110° to app. ii.; and 

 the capacity of the air app. is to the lac app., therefore, as 1 to I '58. If the divided 

 charge be corrected for an assumed loss of only 3°, being the amount of previous loss 

 in the same time, it will make the capacity of the shell-lac app. 1*55 only. 



1265. Then app. ii. was charged, and the charge divided thus : 



App. i. Air. App. ii. Lac. 



0° . . . . 



.... 256° 

 .... 251 

 Charge divided. 

 146 ... . 



.... 149 

 a little .... after discharge. 



. . . . a little after discharge. 



Here app. i. acquired a charge of 146°, while app. ii. lost only 102° in communi- 

 cating that amount of force; the capacities being, therefore, to each other as I to 1*43. 

 If the whole transferable charge be corrected for a loss of 4° previous to division, it 

 gives the expression of 1*49 for the capacity of the shell-lac apparatus. 



1266. These four expressions of 1*47, 1*50, 1*55, and 1*49 for the power of the 

 shell-lac apparatus, through the different variations of the experiment, are very near 

 to each other ; the average is close upon 1*5, which may hereafter be used as the ex- 

 pression of the result. It is a very important result ; and, showing for this parti- 



