produced in Gases by Rontgen Rays Sfc. 429 



out of tlie flame or the Rontgen rays, and then separated and 

 tested separately, it was found that D had retained its charge 

 practically undiminished, and that C had acquired a very 

 slight charge of the opposite kind. 



§ 5. Leakage of Electricity from an Electrified Body in 

 gases other than air at ordinary pressure, due to the presence 

 of uranium. 



We were able to investigate the rate of leak in different 

 gases by means of the smaller piece of uranium mounted in a 

 glass bulb as described in § 2 (fig. 3) . The gas used was 

 first stored in a reservoir over water. It was then bubbled 

 through strong sulphuric acid and passed over caustic potash, 

 calcium chloride, and phosphoric anhydride into the glass 

 bulb. The bulb was first exhausted to an atmospheric 

 pressure of about 6 millim. ; then the gas to be used was 

 passed into it. It was again evacuated and refilled. This 

 was repeated about twenty times. Finally, it was strongly 

 heated so as to draw off any adhering layers of the gas which 

 had previously been in the bulb, and then allowed to cool in 

 an atmosphere of the gas at 760 millim. pressure. One of 

 the tubes was then sealed up ; the other was closed by a well- 

 fitting and well-greased glass stop-cock. 



The following tables give the results obtained with the 

 gases we have experimented on : — 



Hydrogen. 







Leakage per minute 



Volta 



ge. 





in sc. divs. 



2^ 



^olts. 





32 



4 



n 





37 



22 



» 





39 



34 



5) 





38 



100 



11 





39 



135 



11 





38 





Oxygen. 





4 



it 





125 



96 



ii 





157 





Carbonic Acid 





4 



n 





94 



95 



ii 





167 



238 



ii 





183 



255 



ii 





180 



2900 



ii 





Spark discharge. 



[Sensibility of electrometer 140 



sc. divs. per volt.] 



Ml. Mag. S. 5. Vol. 43. 



No. 265. 



June 1897. 2 K 



