60 



o 

 a 

 '2 50 



& 



40 



30- 



zo 



T. Mizuno on the Action of the Coherer. 

 Tier. 4. 



453 



V 



7^z? Z.£/ip Balls 



0,V£ l.£/l£ B 4LI. 



7»>>Mi 



/<90 



/7C 



/<5<9 



/SO 



AAJT/MOWy J ****** 



10 20 



Number of Sparks. 



10 



cO 



