328 Br 0. Olearski, Some experiments on the dielectic [Nov. 23, 



In each horizontal line the distance between the movable 

 electrodes is given and the corresponding pressures of different 

 gases at which the first discharge appeared in the tube. 



From these experiments air would seem to be intermediate 

 between its constituent gases; while the mixture of oxygen and 

 nitrogen in the ratio of 61% vol. to 39°/ , is stronger even than 

 oxygen. The difference is however not larger than the possible 

 errors of the experiment. Another experiment has given for the 

 same mixture and for oxygen numbers almost exactly equal. 



The following are the means of three measurements every 

 one of which included oxygen, air and nitrogen : 



There is a very small difference in the electric strength of 

 oxygen, nitrogen and air. Oxygen is a little stronger than nitrogen 

 for low pressures just as Wiedemann and Ruhlmann found, 

 whereas Faraday has shewn that under the pressure of an atmo- 

 sphere nitrogen is the stronger. Generally the curves given on 

 the diagram of Wiedemann and Ruhlmann agree with numbers 

 found here as measuring the electric strength, which shews that 

 quantities of electricity carried at a discharge measured by Wiede- 

 mann and Ruhlmann are proportional to the potential which is 

 necessary to introduce the discharge. Air appears however to be 

 intermediate between oxygen and nitrogen even under the pressure 

 of 6 mm. of mercury. 



