404 PELTIER ON THE CAUSES OF THE 
which a copper wire 4 passes. This copper wire is soldered to 
a support of the same metal c, which rests upon cakes of resin 
dd. Some water saturated with soap is poured into this cap- 
sule, and with a very small tube we produce a large cloud ee, 
formed of minute bubbles which rise and keep their position 
above the capsule. At some distance from the cloud of soap 
bubbles is suspended an insulated ball of copper /, which com- 
municates with an electric machine. When we turn the ma- 
chine, we see the extreme bubbles disappear shooting towards 
the vitreous ball, and the remainder of the cloud itself becomes 
strongly vitreous ; which shows, that all the parts which shot 
away and were dissolved were resinous. We might take a cap- 
sule alone without any metallic support; but the tension of the 
remainder of the cloud increases much less, unless it be made 
of very large size, in order that the vitreous electricity be far 
enough off not to retard the resinous radiation towards space. 
When the cloud is small, and when we do not afford a means to 
the vitreous tension of removing to a distance from the portion 
in front of the electrified body, we have only a feeble result ; 
whilst with the copper foot, which facilitates this separation and 
is a substitute for the greater size of the cloud, a single turn of 
the machine is more than is necessary to give to the remainder 
a tension capable of destroying the gold leaves of an electro- 
scope placed in immediate contact. 
49. Not to leave any doubt respecting the induction of the — 
globe and of space, an analogous experiment must be repeated 
during very hot, clear and dry days, like those which took place 
from the 10th to the 15th of September of the year 1841. An ~ 
insulated disc is placed in the open air communicating with an 
electrometer, and as much disengaged as possible from all lateral 
induction of the buildings; a small syringe is filled with di- 
stilled or common water, which has no influence on the result, 
and a small stream is projected vertically, so that it falls in 
small drops on the insulated disc. In favourable days like those 
I have just mentioned, the short time that the water takes to 
pass through the curve of its projection, is sufficient for it to fall 
again charged with vitreous electricity. If the atmosphere is 
less warm, and the evaporation is less rapid, it is rare that this 
time suffices to give the necessary tension to the water. The — 
concurrence of a quick evaporation is necessary, under the induc- 
tion of the ground and of space, for so short a time to suffice for 
