186 
MR. GASSIOT ON THE POSSIBILITY OF OBTAINING A SPARK 
my instrument ; and I now purport describing the different arrangements of the 
voltaic battery with which I used it. 
14. I have had in constant action for upwards of twelve months a voltaic battery 
consisting of the usual elements, zinc and copper, each pair being placed in a separate 
circular glass vessel containing about a quart of rain water. The entire battery is 
composed of 150 series or pairs. A minute but brilliant spark is perceivable on com- 
pleting the circuit with charcoal terminals : it will charge a Leyden jar sufficiently 
to deflect the leaves of a gold-leaf electroscope, and a Leyden battery of twelve one- 
gallon jars sufficiently to fuse the ends of a fine steel wire or point of a penknife; but 
although the greatest care was taken in adjusting the micrometer electrometer (12.), 
not the slightest appearance of a spark could be perceived through the minute space 
of g^th of an inch. 
15. Recollecting that Professor Daniell had a water battery of an extended series, 
I applied to that gentleman for permission to use it, which he kindly granted me. This 
battery, which Mr. Daniell has described in his Introduction to the Study of Che- 
mical Philosophy, § 743, consists of a series of 1024 pairs ; attractions as well as re- 
pulsions, when the electrodes terminate in strips of gold leaf, are plainly perceptible ; 
a minute but distinct spark is seen on completing the circuit; but with the battery 
alone the spark could not be obtained through the space of g^gth of an inch. 
16. The property of the voltaic battery, particularly when extended to such a series 
as that of Mr. Daniell’s (15.), to charge a Leyden battery is well known; and 1 
accordingly found, when a battery of nine jars was introduced in the circuit, I ob- 
tained distinct sparks to a distance varying from g^- 0 th to g^ths of an inch. When 
the space was reduced to g^- 0 th or g^- 0 ths of an inch, the sparks appeared in quick 
succession, the intervals between the sparks varying from two seconds to twelve 
seconds; but when the space was increased to g^ths, it required at least two minutes 
before there was sufficient accumulation or power to force a passage for the spark 
through such a space. 
17- Having been, by the invitation of Professor Daniell, witness on the 16th of 
February 1839 of the powerful effects obtained by a series of seventy of the large con- 
stant battery, I was induced to prepare 100 of precisely the same dimensions. On 
the first day I excited that battery (14th of July), and when I was favoured with the 
company of Dr. Faraday, I also excited 100 of the smaller cells already described (10.) ; 
but neither with these two powerful batteries combined, or separate, could any appear- 
ance of a spark be observed until contact was made and the circuit completed. 
18. Dr. Faraday placed a silk handkerchief between the electrodes of the 100 
large cells, and although the terminal balls or ends of the connecting wires were 
pressed together and then separated, and this repeated several times, no effect could 
be obtained through this minute space ; or, in other words, one thickness of a silk 
handkerchief interposed between the electrodes of such a powerful battery was suffi- 
cient to prevent any perceptible action. 
