38 Experiments with the Elementary Voltaic Battery. 
Z. 2m. 
2 404° 
3/ 395 
4’ 380 
350 
In this experiment, at the close of the 5’, dark colored scales be- 
gan to fall from the copper, and the decline was so rapid as to pre- 
vent any acurate observation of it; but after the scaling was com- 
pleted and the newly exposed surface was gently washed with wa- 
ter, the same copper gave with z.2 in. 
: 2’ 
146° 
3 145 
4/ 144 
A new copper immersed 2’ in same solution of boiling muriatic 
acid, and then gently rubbed and washed off with water, gave with 
z. 2 in. 
2’ 130° 
3 128 
The same copper re-immersed, and dried by exposure for 7’ with- 
out wiping gave with z. 2in z. 4 in 
2! 175° 2 170° 
3 166 3’ 170 
The same after eight hours repose, gave with 
Zz. 3 in. z. 2 in. Z. 3 in. 
M2: 163° "140° 150° 
y . 466 =a = 150 
139 150 
No. 1 copper treated as before, with hot solution of nitric acid 
and water, and allowed eight hours repose without wiping, gave with 
z.3 im z. 2 im z.3 in 
ad 200° 134° 142° 
3! 160 132 140 
4’ 150 130 138 
9. In order thoroughly to test the correctness of the above ob- 
servations, we repeated them with three entirely new coppers of 2 
sq. in. surface, and zincs the same. 
No. 1 copper. No. 2 copper. = No. 3 copper. 
1’ 49° 40° 41° 
2 AS. <3 32 39 
3 41 31 33 
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