between Plates for small Distances. 

 Table VI. — Carbon Dioxide (surface blown), 



157 



Distance in 



Potential in ' 



Distance in 



Potential in 



Ware-lengths. 



Volts. 



Wave-lengths. 



Volts. 



10 



100 



95 



364 



1-5 



150 



15-0 



412 



1-5 



182 



225 



408 



20 



250 



31-5 



420 



2-5 



250 



36-0 



480 



25 



300 



52-5 



560 



3-0 



300 



620 



592 



40 



304 



93-0 



630 



4-5 



340 



1100 



736 



5-5 



360 



1250 



780 



90 



376 







Table VII.- 



— Carbon Dioxide (surface 



not blown). 



Distance in 



Potential in 



Distance in 



Potential in 



Wave-lengths. 



Volts. 



Wave-lengths. 



Volts. 



10 



104 



170 



568 



20 



212 



18-5 



582 



25 



260 



30-5 



618 



3-0 



300 



38-5 



660 



3-5 



320 



525 



678 



4-5 



360 



77-5 



732 



5-0 



412 



84-0 



768 



7-5 



464 



107-0 



870 



12-0 



516 







maintained over the surfaces, while for the lower branch the' 

 gas was quiescent. This distinction gave rise at first to what 

 appeared to be inconsistent readings, but the apparent wide 

 discrepancy in the readings wns found to be due to the cause 

 indicated below. In the case of the gas in motion, a jet of 

 C0 2 was allowed to impinge on the contact-surfaces ; not,, 

 however, at the point where contact would take place, but 

 remote from the region of contact : thus it was hoped to 

 secure a gentle flow of the gas, which would naturally spread 

 out over the surfaces. The values from which the lower- 

 limb of the curve were obtained were those taken after the 

 C0 2 had filled the box and the supply had been cut off. 

 The readings were taken in from two to four minutes after 

 the box was filled. The separate readings are indicated for 

 the upper curve (surface blown) by a cross {x). The read- 

 ings for the lower curve (surface not blown) by a circle (o) . 

 As an explanation of the two branches of the curve I 

 submit the following hypothesis : — We know from general 



