422 JJrs. Beattie and De Smolan on the Conductance 



(«) 



Voltage. 



6 

 10 

 44 



88 



176 



750 



1250 



2000 



3000 



Leakage per minute 

 in sc. divs. 



56-0 



65-5 

 113-0 

 128-0 

 156-0 

 219-0 

 229-0 

 260-0 

 276-0 



[Sensibility of electrometer 24 sc. divs. per volt of subsidence 

 of difference of potentials between coatings of A.] 



We also investigated the conductivity produced in air by a 

 second piece of uranium 3 centim. long, 1 centim. broad, 

 and about "5 centim. thick. This was mounted firmly in a 

 glass bulb 6 centim. long, 3 centim. diameter, on a platinum 

 wire fused into one end of the bulb. The uranium in the 

 bulb was surrounded throughout two-thirds of its length by a 

 zinc cylinder 1*5 centim. in diameter. This zinc cylinder 

 was kept in position by a stiff platinum wire fused into the 

 other end of the glass (see fig. 3). Two glass tubes were 



Ficr. 3, 



BATTERY 



TO ELECTROMETER 



TO SHEATHS 



fixed on to the bulb ; by means of these any desired gas could 

 be introduced or any desired vacuum produced. Round the 

 outside of the glass bulb a strip of tin-foil was placed and 

 connected to the case of the electrometer. This prevented 

 vitiation of our results by a leak between the two electrodes 

 over the outside of the glass. The bulb was first evacuated 

 and then filled with dry air. The uranium was then con- 

 nected to the insulated terminal of the electrometer and the 

 zinc to one terminal of a battery or of an electrostatic induc- 

 tive machine, the other terminal being connected to the case 

 of the electrometer. For voltages up to 100 volts the ter- 

 minal was kept connected to the zinc while the leakage due 



