1090 



The intensity of I lie ciuTeiit in the condeiisor was determined 

 from the time which a binant electrometer of Doi.ezai.ek needed, to 



Fig. 1. 



he charged. The tension was snpplied by a battery of small piles 

 and controlled with an electrometer of Wulff. All conductors, the 

 discharge tube, and the electrometer were pi-otected by tin-foil in 

 order to prevent electro-static disturbances. 



The argon was purified according to the method of Gehlhoff. During 

 the measurement there always was found a small impurity, probably 

 due to gases from the ebonite, by which the condensor was 

 isolated. The pressure increased about by 0.00080 mm. in 24 hours. 



The quartz lamp was fed by a battery. After some time the radiation 

 proved to be satisfactorily constant, which was controlled by a 

 thermo-pile. 



3. We have made measurements on the relation between current 

 and tension for a constant distance of the condensor plates and 

 on the relation between current and plate distance for a constant 

 intensity of the field. 



In fig. 2 and 3 the results of the best measurements have been 

 represented graphically. Both curves show typical sudden changes of 



