378 On the Galvanic Polarization of buried Metal Plates. 
for five minutes in the wire conductor, and I thereby obtained 
the numbers exhibited in the following Table ; in which G indi- 
cates the effect of the galvanic current, E that of the terrestrial 
current, and P that of the polarization expressed in divisions of 
the galvanometer. The effect of the polarization was observed 
1 minute 30 seconds after the removal of the cell. 
I. When the two currents passed in the same direction. 
P 
E. are a 
ES G-+E 
129-8 34 0-026 
129:3 3-4 0-026 
123-0 20 0-021 
108-2 24 0-022 
II. When the current passed in opposite directions. 
P 
ak: 
: es Gan 
1245 54 0-043 
122-7 51 0-041 
107-4 3:8 0-035 
109-2 3:5 0-031 
From these experiments, it follows that the mean value of 
ee Spas 
Gan * 0:0237, that of GE 0:0375 ; so that when the gal- 
vanic and terrestrial currents pass in opposite directions, the 
polarization of the buried metal plates is greater than when they 
pass in the same direction. 7 
Immediately on the removal of the cell, the effect of the gal- 
vanic polarization was greater by two or three divisions of the 
galvanometer scale than it was after the lapse of 1 minute 30 
seconds ; and after that period the effect still continued gra- 
dually to diminish. In order to exhibit the law of this diminu- 
tion I subjoin the following Table :— 
Time after the removal, Deviation of the gal- 
of the cell. vanometer needle. 
1 minute. 23:0 divisions. 
” 21°38 ” 
” 211, 
” 20°7 ” 
” 20:3 39 
20:0 a 
” 19-9 ” 
”? 19:7 bP 
” 19°5 ” 
” 19°4 ”? 
SUMMONS Str CS bo 
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