148 
MR. DAN I ELL ON VOLTAIC COMBINATIONS. 
tion of the greater action, were in the same direction as the original battery current, 
I included a galvanometer of a coarse construction, and consisting of a single large 
needle, in the circuit with the voltameter. I found that the needle was strongly de- 
flected to the E., and that the deflection increased as the action rose with the rising 
temperature. Upon the sudden cessation of the action in the voltameter, the needle 
was suddenly released from its coercing force, and swang violently backwards and 
forwards W. and E. till it finally rested a few degrees to the W. ; proving that the 
residual current which passed through the voltameter was in the opposite direction 
to the original current, and was the excess of a counter force which had power 
enough to arrest its course. 
The cover of the steamer was now removed, and it was found that the bottom was 
covered with a considerable quantity of condensed water, which was slightly acid, 
from the leakage of one or two of the cells. 
Upon taking out some of the connecting wires between the cells, some action still 
remained both upon the needle and voltameter, which was not wholly stopped till 
four wires were removed ; proving the existence of a current in some circuit which 
was different from the main circuit of the battery. 
I now tested the direction of the current in each separate cell of the battery, by 
leading extra wires from the zinc and copper to a second galvanometer, and found 
all in the normal direction (causing a permanent deflection of the needle 50° E.) ex- 
cept one, which presented a contrary current, and deflected the needle 30° W. Upon 
another occasion I found the current in six separate cells E., and three in the oppo- 
site direction, or W. ; and once again one cell was found to be neutral, two reverse, 
and six direct. I proceeded to investigate with great care a phenomenon which pro- 
mised at first to afford the explanation of the stoppage of the battery current. Let 
fig. 1. (Plate VIII.) represent the section of the voltaic combination : abed will be the 
steam-vessel, and the nine cells, with their connecting wires, will be represented by 
the nine smaller circles 1, 2, 3, 4, 5, 6, 7 , 8, 9. In the experiment which I am about 
to describe, the electrodes e and f were unconnected, but all the short connecting 
wires were in their places. Each cell was tested by the galvanometer by means of 
extra wires, as at g. The cells 1, 2, 3, 4, 5, 6, 7? separately deflected the needle in 
the normal direction, or from 30° to 40° E. No. 8. deflected it in the opposite direc- 
tion, or 40° W. The connexion between 8 and 9 was broken, and the same cell de- 
flected the needle 35° E. The connection was then broken between 8 and 7? and the 
deflection was 30° E. ; and when both wires were replaced, the needle returned to 
40° W. 
The whole circuit was then completed by the connection of 1 and 9 by a short wire, 
when, notwithstanding a path was open for the circulation of the battery current, the 
deflection caused by the single cell No. 8. increased to 55° W., which was contrary 
to the direction of the main circulation. While the circuit was thus complete, the 
other cells were again tested, with the following result : — • 
