Disjunction- currents through Gases of various Densities. 21 



Deflections. 

 6-2 

 6-2 

 7^2 



Mean . . 6*5 



Experiment 18. — The same as No. 16 : — 



Deflections. 

 17-0 

 15-5 

 14'0 



Mean . . 15*5 



A few other other observations gave the same result — that is, 

 a considerably greater deflection for carbonic acid than for air. 



Experiment 19. — The glass cylinder was filled with hydrogen 

 which had been dried before entering the cylinder. The follow- 

 ing deflections were thereupon observed : — 



Deflections. 

 13-5 

 11-5 

 11-5 



Mean . . 12*2 



Experiment 20. — The cylinder was filled with air :— 



Deflections. 



6-0 



5-5 



57 



Mean . . 5*7 



Experiment 21. — The same as No. 19: — 



Deflections. 

 14-3 

 15-3 

 14-8 



Mean . . 14-8 



With hydrogen, then, the deflection was considerably greater 

 than with air. When, on the contrary, the cylinder was filled 

 with coal-gas, the deflection was but very little greater than with 

 atmospheric air. With the former mixture the deflection 13*5 

 was observed, and with the latter 11*9. 



3. In order to investigate the dependence of the disjunction- 

 current on the density of the gas in which the spark is formed, 

 experiments were made with atmospheric air, carbonic acid, and 



