38 Experiments with the Elementary Voltaic Battery. 
Gs v2) iia 
Qs ») “AOS 
3! 395 
A! 380 
By 300 
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 mumiatic 
acid, andthen gently rubbed and washed off with water, gave with 
z. 2 i. 
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° 7 2! 170° 
3! 166 3! 170 
The same after eight hours repose, gave with 
z.3 in. z. 2 in. z.o in. 
a 163° 140° 150° 
3/155 139 150 
4’ 155 139 150 
No. 1 copper treated as before, with hot solution of nitric acid 
and water, and allowed eight hours repose without wiping, gave with 
Z.o in. VA Mia Zines ine 
Q/ 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! 45 32 39 
3! 4] 31 33 
