Charged Bodies at Moderate Temperatures. 



101 



minutes the leak — whether tha charge were positive or nega- 

 tive — rose to 40, 50, or more volts per minute. This increased 

 leak continued for one or two minutes after the flame was 

 extinguished, then gradually decreased until the normal rate 

 of leak — about 1 volt per minute — was again reached. If the 

 potassium bichromate was again heated without a second 

 supply of iodine being sprinkled over it, the increased leak at 

 the end of eight or ten minutes' heating was again observed. 

 Potassium bichromate which had once shown this effect, and 

 had been laid aside for a week, gave again the increased leak 

 when heated at the end of that time. 



Potassium chromate sprinkled with iodine and treated 

 exactly as above described gave no increased effect when 

 heated. 



Table showing no increased rate of leak when iodine alone or potassium 

 bichromate alone, and showing increased rate of leak when potassium 

 bichromate and iodine, or potassium bichromate and bromine together, 



zinc plates and heat applied to outside of 



sLu-iouiiumg iron uo.v. 















Microamp. 



Charged to 









Dr 



op of 





per min. 



Zinc plates alone +220 volts. 





With flame. 



8'5 ' 



rolts 



i in 12 



mins. 



•00000013 



Zinc plates with potas- 1 .inc. 

 siuin bichromate ... j " 





{No „ 

 \ With „ 



io-o 



21-0 



» 



.. 18 



» 



•00000021 

 •00000021 



Zinc plates with iodine +206 „ 





j No „ 

 1 With „ 



3-5 

 21-0 



" 



„ 4 



., 21 



" 



■00000017 

 •00000019 



Zinc plates with potas- ~\ 



sium bichromate and 1 .ono 

 bromine on the bi- ( " " 

 chromate J 



r n.04. 



No 



30 



jj 



„ 4 





•00000014 



| 11.07. 



With „ 



135 





„ 





•00000042 



| 11.13. 



With „ 



400 





,, 2 





•00000380 



111. 15. 



No 



540 



'• 



„ 1 



min. 



•000010CO 



Eecharged to +206 volts. 







11.20. 



No flame. 



160 ^ 



rolls 



5 in 1 



min. 



•00000300 





11.21. 



No 



4-5 



., 



„ 1 



n 



•00000085 





11.22. 



No 



20 





„ 1 



)» 



•00000038 





11.23. 



No 



10 



,, 



» 1 





■00000019 



The insulated zinc plates were next taken out and the 

 potassium bichromate, on which the iodine had been sprinkled, 

 taken off them. It was then found that no increased leak 

 was nroduced on heating when the cleaned zinc plates with 



i • • • 



nothing on were charged to 213 volts positive. 

 28th Oct., 1898. 



Zinc plates with potas- 

 sium bichromate on 

 the plates and iodine 

 on the bichromate ..._ 

 29th October. 



Charged to 



+ 232 volts. 



Zinc plates with potas- ^ 

 sium bichromate used I 

 on 28th, no more }■ +208 

 iodine sprinkled over j 



il ; 



P.M. 



5.03. 

 5.08. 

 5.10. 

 I 5.12. 



A.M. 



f 10.12. 

 I 10.15. 

 I 10.i0. 

 -j 10.25. 

 I 10.20. 

 | 10.27. 

 V 10.28. 



No 

 With 

 With 

 With 



No 



With 



With 



With 



No 



No 



No 



flame. 







Microamp. 





Drop of 



per min. 



6 



volts in 5 mins. 



•00000022 



5 



2 



•00000047 



30 



2 



•00000285 



42 



„ ,, 1 min. 



•00000798 



6 



volts in 2 mins. 



•00000057 



12 



„ „ 5 „ 



•00000046 



19i 



„ „ 5 ,, 



•00000075 



27 



,, „ 1 min. 



•00000513 



38 



„ >, 1 ., 



•00000722 



20 



„ » 1 >, 



•00000380 



4 



„ „ 1 ., 



•O0J00O76 



