Transmission of Excited Activity of Radium to Cathode. 527 

 2. Description of Apparatus. 

 The cylindrical metal vessel V (fig. 1), which could be 

 filled with emanation when desired, was connected to the 



Vie. I. 



a 



C„ 



h 



Radium Solution 



v 



To Pump-- -; — -fa= 



J 



T 



li 



7£ Pressure Cauces 



positive pole of a battery of thirty small storage-cells. The 

 wire AB (14*5 cm. long) was screwed into a stouter rod AC 

 connected to the negative pole of the battery, and passing 

 through a rubber stopper E fitting air-tight into the neck of 

 the vessel V. The portion AA' of the rod AC projected 

 about 6 cm. into the vessel Y, and another rod BD 6 cm. 

 long was screwed to the lower extremity of AB, which was 

 therefore exposed to a uniform electric field. 



To obtain a constant supply of emanation, a strong solution 

 of radium salt was placed in the glass bottle R provided with 



