during the Absorption of Electrons by Platinum. 101 



The numbers in the eighth column represent the values o£ 

 the effect in volts obtained by producing the line through the 

 points back to where it cuts the voltage axis, and adding to 

 the negative volrage at this point on the axis half the value 

 of the potential drop in column five. Columns nine and ten 

 enable an approximate estimate to be made of the temperature 

 of the grid, and also the correction in column eleven to be calcu- 

 lated. This correction will be considered more fully below. 

 It will be seen that the numbers in the last column are in 

 very good agreement. The agreement between the last five 

 is very much better than that of tfre first with any of the 

 others. We have, however, carefully compared the obser- 

 vations and have not been able to detect anything in the 

 numbers belonging to the first set which would warrant their 

 rejection. The mean of the whole six observations is 5*65 

 volts. If we reject the first observation the mean is reduced 

 to 5*51 volts. 



§9. Grid saturated with Hydrogen. 



Experiments were made with the grid of platinum strip 

 after it had been saturated with hydrogen by electrolysis 

 of dilute sulphuric acid for varying periods of time. The 

 results are exhibited in the following table : — 



Number of 

 Experiment. 



Time electro- 

 lysed since last 

 experiment. 



Interval 



(seconds). 



P • 



1 a 



CO 



'o 



> 



R 



P4 



PI 



CD 

 Sh 



CD v 



Saturation cur- 

 rent XlO 5 . 



Uncorrected 

 value (volts). 



o 



CD /->. 



1 1 

 to O 

 "go 

 o 



o ,g 



6. 1 



0> -^ 



O w 



1. 



12 hrs. 



30 





3-88 



166 



(1) 13-55 



5*72 



15-50 



•26 



5-19 



2. 



3. 



20 hrs. 



30 





362 



16-8 



(1) 5-67 



4-77 



14-8 



•25 



4-25 



Eunning 



since last 



experiment. 



30 



•005 



362 



16-0 



(2) 7-08 



467 



15-2 



•25 



4-50 

 4 63 



4. 



5. 



>> 



60 





362 



160 



(1)15-31 



5 - 15 



15-32 



•25 



» 



60 





362 



160 



(1)21-67 



5-51 



15-28 



•25 



4-99 



6. 



7. 



Recharged. 



60 





3-42 



5-0 



(1)10-4 



4-71 



15-16 



•08 



4-36 





30 





324 



5-0 



(1) 26-4 



4-23 



15-14 



•08 



3-88 



8. 



Recharged. 



30 





304 



50 



(1)27-4 



5-87 



1547 



•07 



5-63 

 5-79 



5-75 



9. 

 10. 





30 



•012 



302 



5-0 



(1) 15-7 



6-13 



139 



•07 



Recharged. 30 





302 



5-0 



(1) 29-9 



6-09 



14-4 



•07 



