1896 - 97 .] Electrical Properties of Fumes from Charcoal. 321 
at diminishing electric potentials during the time of observation. 
We intend to continue these experiments, and to arrange to find 
the leakage at different constant electric pressures. 
§ 12. The marked difference in the leakage obtained when the 
horizontal tube was of small bore (3'8 cms.) and when it was of 
larger bore (15'3 cms.) may be contrasted as indicated in the last 
four results given for spirit flame. We also tried how long the 
fumes retained this conductive quality, but in every case we found 
that the leakage stopped in less than a quarter of a minute after the 
flame was extinguished, or removed from the bottom of the funnel. 
Closing the top and bottom of the funnel immediately after the 
flame was removed, we still found that the conductive quality of 
the air and fumes ceased within a quarter of a minute. 
