BEFORE AND AFTER COMPLETION OF THE VOLTAIC CIRCUIT. 
49 
gold-leaf electroscope was notably affected. The instrument used bv Mr. Grove, 
whose original experiments I had the pleasure of witnessing in the laboratory of the 
London Institution, was the same as is represented in fig. 6. Nothing can be more 
decisive than that the static effects of the voltaic battery are not due to the contact of 
dissimilar metals ; as in this arrangement, only one metal, platinum, is used ; but this 
battery, whose action is, in itself, so purely chemical, presents to us a full corrobora- 
tion of the static effects preceding the development of chemical action. 
35. A series of forty cells, the same as are described in Mr. Grove’s paper*, were 
charged with oxygen and hydrogen ; these sensibly affected the gold-leaf electroscope, 
fig. 3. This arrangement was kept charged for upwards of three months. No de- 
crease in the gas of the oxygen tubes could be detected. Whenever the terminals 
were tested by the electroscope, they invariably exhibited the usual signs of tension ; 
but not the slightest chemical or dynamic effect could be obtained until the entire 
circuit was completed. 
36. Here we have a battery, the active elements of which are two gases, which, 
with a closed circuit, immediately enter into active chemical combination ; remaining 
for upwards of three months in such a state of tension as at all times to affect the 
leaves of an electroscope ; but in which no amount of chemical action could be de- 
tected whilst the circuit remained open. 
37. It now became a matter of some interest to ascertain, first , the minimum 
amount of series with which the gas battery charged with oxygen and hydrogen would 
exhibit static effects ; and, secondly, whether, when it was charged with gases which 
do not enter into chemical combination, any signs of tension could be elicited. 
38. By careful arrangement I obtained an attraction in the gold leaves of the elec- 
troscope (fig. 6) with a series of nine pairs ; with twelve or fourteen, the effects are 
very distinct, and required no very delicate manipulation. The series of forty pairs 
was then charged with oxygen and nitrogen ; at first the electroscope was affected, 
and chemical action as well as dynamic effects were obtained with the closed circuit ; 
these, however, were evidently due to impurities in the nitrogen (this gas was ob- 
tained by burning phosphorus in common air; the oxygen by electrolysis) : after 
keeping the circuit closed for two days, these effects ceased, when not the slightest 
static, chemical or dynamic actions could be detected ; the volumes of the gases re- 
maining perfectly stationary, whether the circuit was closed or open. 
39. From the preceding experiments we learn that, when the gases used in this 
battery are oxygen and hydrogen (which will from their affinity for each other enter 
into chemical combination), a series of ten or twelve is sufficient to develope static 
effects ; but that, when charged with gases which have not this power, viz. oxygen 
and nitrogen, even a series of forty does not affect the electroscope. 
40. The advantage of using oxygen and hydrogen is, that although the hydrogen 
is slightly absorbed by local action with the atmospheric air in the solution, action 
* Philosophical Transactions, 1843, plate 5. fig. 1. 
MDCCCXLIV. 
H 
