quirqd is, to take two narrow slips of com- 
i won window-glass, each about an- inch 
broad, and three or four inches long. Let 
[ a narrow -slip of gold leaf then be placed be- 
| tween the glasses, with about an inch at 
each end hanging beyond the glasses, which 
by some means should be pressed closely 
1 together. One end of the slip of gold leaf 
| should communicate with the outer coat- 
\ ing of the phial ; and when it is charged, one 
: knob of the discharging rod must be applied 
; to the other end of the leaf, so as to send 
the charge through it. When the glasses' 
are taken asunder, it will be found that the 
gold has been melted, and the substance of 
it actually incorporated with the glass, which 
| consequently must have undergone a partial 
fu sion itself. 
By a smart shock of electricity from a 
charged phial, or a battery, a plant may be 
killed, and the experiment will best succeed 
with the common balsam or impatiens. The 
| smaller animals may also be deprived of life ; 
but human art has not yet been able to con- 
' struct a battery large enough to kill an ani- 
mal above the size of a sheep or a dog. 
\ The immediate or proximate cause of the 
death of animals by electricity, or by light- 
ning, which is natural electricity, has not 
; yet been ascertained. It was once supposed 
that the living principle was extinguished by 
the bursting of some blood vessel, from the 
violence of the shock ; but a dog which was 
killed by lightning, was carefully dissected, 
and none of the ve.>sels found in the least in- 
jured. Beccaria recovered some persons 
apparently struck dead by lightning; and 
when questioned with respect to the pain or 
suffering which they endured, they only 
complained of an unusual numbness or wea- 
riness in their limbs. \ he flesh of animals 
killed bv electricity is rendered extremely 
tender, and is recommended by Dr. Frank- 
lin as an article of luxury. It will also pu- 
trify in a much shorter time than the flesh of 
those which are killed in any ordinary way. 
Electricity augments the natural evapor- 
ation of fluids, and especially of those fluids 
which are most subject to evaporation of 
I . themselves ; and it has a greater effect on 
ai ' fluids, when the vessels containing them are 
non-elecirics. If a humid body, a sponge 
for instance, is placed upon a conductor po- 
I sitively electrified, the evaporation will pro- 
ceed much more rapidly, and it will be much 
sooner dry, than a similar body differently 
circumstanced. 
Dr. Priestley also supposes that plants, 
when electrified, vegetate earlier and more 
vigorously, than those which have not been 
subjected to this influence. 
That electricity increases the insensible 
perspiration of animals, may be inferred 
from the circumstance that electrified ani- 
f rivals are always lighter than those which are 
not. 
The stream of electrical fluid has no sen- 
sible heat, but even appears cold to the 
touch ; yet we have seen that the more iriT 
flammable bodies, and particularly spirit of 
wine, mav be ignited by it;, in this respect 
| it remarkably differs from fire or caloric. 
The luminous effects of electricity are not 
the same in vacuo as in the air, and the 
reason of this is, that dry air is a non-con- 
ductor. Thus if a ware with a round end is 
included in an exhausted receiver, and pre- 
ELECTRICITY. 
seated to a conductor of an electrical ma- 
chine, every spark will pass through the va- 
cuum in a broad stream of light, visible the 
whole length of the receiver, moving With 
regularity (unless it is turned back by some 
non-electric) ; and then dividing itself into a 
number of beautiful rivulets, which are con- 
tinually separating and uniting in a pleasing 
manner. When the vessel is grasped by the 
hand, a pulsation is perceived like that of an 
artery, and the fire inclines towards the 
hand. A small quantity of air is, however, 
necessary to occasion the most brilliant lumi- 
nous effect. 
Of thunder and lightning, meteors, veater- 
■spouts, &c. — Tt no longer remains a doubt 
among philosophers, that the cause of thun- 
der is the same with that which produces the 
ordinary phenomena of electricity ; the re- 
semblance between them is indeed so great, 
that we cannot believe thunder itself to be 
anv other than a grander species of electri- 
city, naturally excited without the feeble 
efforts of human art. This fluid, probably, 
is diffused through the whole atmosphere at 
all times, either in a smaller or greater de- 
gree ; and is occasionally perceptible to our 
senses, according to the concurrence of na- 
tural circumstances. 
The cloud which produces the thunder 
and lightning may be considered as a great 
electrified body; but- how has the cloud ac- 
quired its electric virtue ? is the reasonable 
demand of an inquisitive mind : and to satis- 
fy this inquiry it will be -necessary to refer 
to what lias been before observed, that this 
power is produced in two modes, by friction, 
and by communication. Bodies electrified 
by friction communicate their virtue to 
other bodies which are susceptible of it, 
provided they are insulated, and at a con- 
venient distance. As air, therefore, is an 
idio-electric body, it is not unphilosophical 
to suppose, that in stormy Weather, especi- 
ally when it is common to observe the 
clouds and the wind take contrary courses, a 
part of the atmosphere, rushing by the other, 
may cause the air to be electrified by the 
friction of its ow n particles, or by rubbing 
against terrestrial objects which it meets in 
its passage, or perhaps against the clouds 
themselves. It is probable also, that the 
inflammable substances, which arise and ac- 
cumulate in the cloudy regions, contribute 
to increase the effects, not only of them- 
selves, but perhaps still more by the elec- 
tric matter which they carry along with 
them. Another circumstance-, which fa- 
vours this inference, is, that thunder-storms 
are more frequent and tremendous in those 
times and places, when and where we have 
reason to conclude that these exhalations 
are in the greatest abundance in the atmo- 
sphere,. as in warm seasons and climates, as 
well as in those places where the earth is fill- 
ed with substances capable of furnishing a 
large quantity of these exhalations, and in 
particular, in the neighbourhood of volca- 
noes.. 
A cloud in a thunder-storm may be con- 
sidered as a great conductor, actually insu- 
lated and electrified ; and it may be sup- 
posed to have the same effect upon those 
non-electrics which it meets with in its 
course, as our common conductors have upon 
those which ate presented to them. If a 
cloud of tin's kind meets with another which.. 
005 
is not ei'ectrified, or less so than itself, the 
electric matter flies oft from all parts to- 
wards this cloud; hence proceed Hashes of 
lightning, and the formidable report ot thun- 
der. 
“ Thunder-storms,” says Beccaria, “ gene- 
rally happen when there is little or no wind ; 
and" their first appearance is marked by one 
dense cloud, or more, increasing very fad 
in size, and rising into the higher regions iff 
the air ; the lower surface black, and nearly 
level, but the upper finely arched, and well 
defined. Many of these clouds seem fre- 
quently piled one upon another, all arched 
in the same manner; but they keep con- 
tinually uniting, swelling, and extending their 
arches. 
“ At the time of the rising of this cloud, 
the atmosphere is generally full ot a great- 
number of separate clouds, motionless, and 
of odd and whimsical shapes. All these, 
upon the appearance ot the thunder clouo, 
draw towards it, and become more uniform 
in their shapes as they approach, till coming, 
very near the thunder cloud, their limbs 
mutually stretch towards one another ; they 
immediately coalesce, and together make 
one uniform mass. But sometimes the 
thunder cloud will swell, and increase very 
fast, without the conjunction of these adsci- 
titious clouds, the vapours of the atmo- 
sphere forming themselves into clouds wher- 
ever it passes. Some of the adscititious 
clouds appear like white fringes at the skirts 
of the thunder cloud, but these keep con- 
tinually growing darker and darker as they- 
approach or unite wilhjt. 
A “ When the thunder cloud is grown to a., 
great size, its lower surface is often ragged, 
particular parts being, detached towards the 
earth, but still connected with the rest. 
Sometimes the lower surface swells into 
various large protuberances, bending uniform- 
ly towards the earth. When the eye is un- 
der the thunder cloud, after it is grown 
larger, and well formed, it is seen to sink 
lower, and to darken prodigiously ; at the 
same time that a number of adscititious 
clouds (the origin of which can never be 
perceived) are seen in a rapid motion, driv- 
ing about in very uncertain directions under 
it. While these clouds are agitated with 
the most rapid motions,, the rain generally 
falls in the greatest plenty ; anclif the agita- 
tion is exceedingly great, it commonly 
hails. 
“ While the thunder cloud, is- swelling, 
and extending its branches over a large tract, 
of country,. the lightning is seen to dart front- 
one part of it to another, and often to illu- 
minate its whole mass. When the cloud has 
acquired a sufficient extent, the lightning 
strikes, between the cloud and the earth, in- 
two opposite places, the path of the lightning 
lying through the whole body of the cloud 
-and its branches. The longer this lightning 
continues,, the rarer the cloud grows, and 
the less dark is its appearance, till at length 
it breaks in different places, and displays a 
clear sky.” 
It is the opinion of the same author, that 
the clouds serve as conductors to convey 
the electric fluid from, those parts of the 
earth which are overloaded with it, to those 
which are exhausted of it. 
To prove that, the earth is often positively 
charged with respect to the. clouds in one 
