1889.] Temperature on the Electric Strength of Gases. 327 
for the electric strength of the liquid CO, for the first spark 
which passed by liberating gas caused such an increase in the 
pressure that the tube was invariably broken. ‘The experiments 
however show that the liquid CO, possesses greater electric 
strength than gaseous CO, under great pressure, and therefore 
that it is a very good insulator. 
The following is a specimen of the observations : 
Pressure of CO, in atmospheres. Air space in millimeters. 
1:25 8 
2 10 
35 115 
6 12°25 
9) 14 
14 155 
23 18: 
When both electrodes were surrounded by liquid CO, the air 
space was more than 24 millimetres. 
Care must be taken not to allow too many sparks to pass 
through the CO,, otherwise CO will be produced and liquefaction 
prevented. 
It was found that the electric strength of highly compressed 
CO, was increased by raising the temperature, though at at- 
mospheric pressure the electric strength of CO, is diminished by 
raising the temperature. 
The electric strength of gases at ordinary pressures diminishes 
rapidly as the temperature imcreases. Thus for hydrogen at 
atmospheric pressure it was found that if fixed terminals in the 
hydrogen were placed in multiple arc with the air terminals 
used in the experiments before described, the distance between 
the terminals in the air in order that as many sparks should pass 
through the air as through the hydrogen had to have the following 
values. 
Hydrogen. 
Temp. Air spaces, 
15 3) 
120 4nd 
140 35 
155 3°5 
160 3°5 
175 3 
200 2°5 
260 2 
300 2 
The electric strength of gases also diminishes rapidly as the 
