226 
Proceedings of Boy al Society of Edinburgh, [may 16 , 
\ min. — 40, 39, 38, 37, 36, 35, 34, 33, 32, 32. 
1 min.— 31, 31, 30, 29, 28, 27, 26. 
1 min.— 25, 23, 22, 22, 21, 21, 21, 20, 20, 19, 19. 
Experiment 4 b . — Plates connected for 30 min. 
10 secs.— 84, 76, 67, 62, 58, 55, 52, 50, 49, 48, 46, 44, 42, 
41, 40, 39. 
1 min.— 38, 37, 36, 35, 34, 33, 32, 31, 30, 30. 
J min. — 29, 28, 27, 27. 
1 min. — 26, 25, 24, 23, 22. 
Experiment 4 c . — Plates unconnected for about 20 hours. 
10 secs.— 34, 27, 23, 21, 18, 16, 14, 13, 12, 11, 11, 10, 10, 10. 
\ min. — 10, 10, 9, 9. 
J miu.— 9, 9, 9, 9. 
1 min. — 8, 8, 7, 6, 6. 
These experiments show that when the plates are left in the 
liquid for a considerable time, some cause produces a great diminu- 
tion of current-strength. This may be either due to increase of 
resistance or to decrease of capacity at the surface layers where 
“ condenser-action” occurs. The above series of experiment does not 
determine to which cause the diminution is due, since half a minute 
elapsed between starting the current and taking readings ; but the 
following series shows that, whether or not there be alteration of 
capacity, there is great alteration of resistance. The galvanometer 
was shunted, and readings were taken every 10 secs, after joining 
the battery into the circuit. 
Experiment 1. — Plates connected for about 40 hours. 
Deflection. — 19, 13, 10, 9, 8, 7, 7, 6. 
Experiment 1 a. — Plates heated, and 48 ohms added. 
Deflection.— 18, 14, 13, 12, 12, 11, 10, 9. 
Experiment lb . — Plates heated, and no additional resistance. 
Deflection.— 25, 20, 15, 14, 13, 13, 12. 
