PRODUCED IN GASES BY RONTGEN RAYS. 
227 
The results are shown graphically in curve II. of fig. 16. 
The corrected value of U = 35'0 centims. per second. 
A = 9'04 volts. 
35 
v = 5‘118 —— — = 6'72 centims. per second, which reduced to 76 centims. 
2-95 x 9-04 1 
pressure becomes 6'76 centims. per second. 
2-95 
T = - - = - 084 second. 
3o 
The gas in this case contained 3'4 per cent, of air. 
The following set of readings was taken for the positive ions in hydrogen saturated 
with aqueous vapour :— 
Temperature = 20° C. X = 2'95 centims. Barometer = 76'7 centime. 
Excess pressure in gasometer = '78 centim. 
,, ,, apparatus = '35 centim. 
9 cells = 18'5 volts. 
2 G 2 
