184 
MR. GASSIOT ON THE POSSIBILITY OF OBTAINING A SPARK 
8. Professor Daniell, in describing some very curious and important experiments 
made with his constant battery when excited with strong acid solutions *, says, “ That 
“ a discharge may take place from the copper of one cell to the copper of the next, 
“ when the regular circle is interrupted between the two, 1 had many opportunities of 
“ observing with the powerful currents with which I had been experimenting; for I 
“ have frequently seen it pass in the form of a spark when the cells had been too much 
“ approximated in the air.” And in his Introduction to the Study of Chemical Philo- 
sophy, § 725, this gentleman also informs us, that, when the energy of the battery has 
been elevated by the repeated impulses of a series, it will project through an interval 
of air in the form of the most dazzling fire. 
9. With this array of authority before me, I certainly entered into the investiga- 
tion with some diffidence : but the inquiry was important. Dr. Jacobi’s experiments, 
to which I have already alluded, proved that with twelve platinum and zinc plates, 
excited with a solution of eight parts sulphuric acid to 100 parts of water, the spark 
could not pass through ^- 0 th of an inch ; and the question was now, whether 
using a more powerful apparatus this alleged spark was obtainable or not. Fortu- 
nately the researches of Professor Daniell have, in the constant battery -f~, placed an 
apparatus in the hands of the experimentalist which enables him to examine his 
results with that care and attention so indispensable in all philosophical pursuits, but 
which were quite incompatible with the acid batteries used in the time of Davy. 
10. My first experiments were made with 160, and subsequently with 320 series of 
the constant battery, each series consisting of the usual elements of zinc and copper, 
each pair being placed in a half-pint porcelain jar, the exciting liquids, solutions of 
muriate of soda and sulphate of copper, separated from each other by brown paper. 
The effects from this battery were of the most brilliant description ; but as they have 
been described elsewhere^, it is only necessary for me to state that this arrangement 
was used in the following experiments. 
1 1 . Fig. 1 . represents a glass globe which was attached to a 
good air-pump, the upper wire sliding through collars of leather 
air-tight, PandN representing the positive and negative elec- 
trodes of the battery (10.) The small balls attached to the 
two wires were then approximated, as near as the eye could 
determine, without being in actual contact; but no sparks could 
be observed even when the globe was exhausted by means of 
the air-pump. 
12. In order to avoid as much as was in my power any 
error in the approximation of the electrodes, I had an instru- 
ment prepared which, in order to understand correctly the 
next series of experiments, it is necessary I should describe. 
* Philosophical Transactions, 1837, p. 121. t Ibid. 1836. 
X Transactions of the Electrical Society. 
