Prof. Bijke on some Properties of the Induced Current. 251 



Medium in which 



the rupture of the 



inducing circuit 



took place. 



Atmospheric air 



Alcohol flame 



Hydrogen flame.., 



Coal-gas flame ... 



Greatest 

 striking distance. 





millims. 

 f 20-4 1 

 1 174 J 





,, 18-9 





(31-4-1 

 130-7/ 





31-05 





/ 76-91 

 177-3/ 









/ 73-01 

 176-9/ 





.... 74-95 



Ratio between the 

 striking distances 

 obtained when the 

 rupture takes place 

 in the given medium 

 and in air. 



1-643 



4-077 



3-966 



The copper plate was 35*4 millims. in diameter. The tapering 

 conductor, also of copper ; was 9 millims. thick at its base, and 

 was 40 millims. in length. 



4. It appeared to me not unimportant to examine if the influence 

 of the flame continued to show itself when the two ends of the 

 inducing wire were connected with the armatures of M. Fizeau's 

 condenser. The following are the results obtained by inter- 

 posing the condenser with which the apparatus is provided : — 



Medium in which 



the rupture of the 



inducing circuit 



took place. 



Electrodes used. 



Greatest striking 

 distance. 



Ratio between the 

 striking distances 

 obtained when the 

 rupture took place in 

 the given medium 

 and in air. 



Atmospheric air... 

 Coal-gas flame- ... 

 Atmospheric air... 



Coal-gas flame ... 





millims. 



95-2 

 113-2 



| 118 



165 



1 



1-88 



1 



1-4 



Ditto 



Tapering cylinder 



Ditto 





The examination of the results given in the last two Tables 

 proves that the influence of the flame is less perceptible when the 

 experiment has been so arranged as to obtain a greater striking 

 distance. 



5. The platinum wires may be left in the flame for a very short 

 space of time — that necessary to produce the rupture ; or, on 



S2 



