28 DR. FARADAY'S EXPERIMENTAL RESEARCHES IN ELECTRICITY. (SERIES XI.) 



J 260. This extraordinary difference was so unexpected in its amount, as to excite 

 the greatest suspicion of the general accuracy of the experiment, though the perfect 

 discharge of app. i. after the division showed that the 113° had been taken and given 

 up readily. It was evident that, if it really existed, it ought to produce corresponding 

 effects in the reverse order ; and that when induction through shell-lac was converted 

 into induction through air, the force or tension of the whole ought to be increased. 

 The app. i. was therefore charged in the first place, and its force divided with app. ii. 

 The following were the results : 



App. i. Lac. ■A^PP- "• Air. 



.... 0° 

 215° .... 

 204 ... . 

 Charge divided. 

 .... 118 

 118 ... . 



. , . . after being discharged. 

 . . . . after being discharged. 



1261. Here 204° must be the utmost of the divisible charge. The app. i. and ii. 

 present 11 8° as their respective forces; both now much above the half of the first 

 force, or 102°, whereas in the former case they were below it. The lac app. i. has 

 lost only 86°, yet it has given to the air app. ii. 1 18°, so that the lac still appears much 

 to surpass the air, the capacity of the lac app. i. to the air app. ii. being as 1*37 to 1. 



1262. The difference of 1'55 and r37 as the expression of the capacity for the in- 

 duction of shell-lac seems considerable, but is in reality very admissible under the 

 circumstances, for both are in error in contrary directions. Thus in the last experi- 

 ment the charge fell from 215° to 204° by the joint effects of dissipation and absorp- 

 tion (1192. 1250.), during the time which elapsed in the electrometer operations, be- 

 tween the applications of the carrier ball required to give those two results. Nearly 

 an equal time must have elapsed between the application of the carrier which gave 

 the 204° result, and the division of the charge between the two apparatus ; and as 

 the fall in force progressively decreases in amount (1192.), if in this case it be taken 

 at 6° only, it will reduce the whole transferable charge at the time of division to 198° 

 instead of 204° ; this diminishes the loss of the shell-lac charge to 80° instead of 86° ; 

 and then the expression of specific capacity for it is increased, and, instead of 1*37, is 

 1*47 times that of air. 



1263. Applying the same correction to the former experiment in which air wasjirst 

 charged, the result is of the contrary kind. No shell-lac hemisphere was then in the 

 apparatus, and therefore the loss would principally be from dissipation, and not from 

 absorption : hence it would be nearer to the degree of loss shown by the numbers 304° 

 and 297°, and being assumed as 6° would reduce the divisible charge to 284°. In 



