ELECTRICITY. 
the production of principles, whilst she mul- 
tiplies their properties so liberally, has in no 
case established two causes for one effect. 
We may apply this remark to the electric 
matter; and the more we inquire into the 
properties of the electric nutter, and those 
of the matter of heat and light, the more shall 
we discover of this analogy between them, 
and the more probable will it appear, that 
tire, light, and electricity, depend upon the 
same principle, and that they are only three 
different effects from the same matter or es- 
sence. 
1st. Of all the means necessary to excite 
the matter of heat, there is none more effi- 
cacious than that which is most necessary to 
produce electricity, namely, friction. 2dly. 
As caloric extends itself with more facility in 
metals and humid bodies than in any other 
substances, so metals and water are conduc- 
tors of electricity in the same manner as they 
are of heat; and, in general, the same con- 
ductors are found equally good for both. 
3dly. Caloric is the most elastic of all bodies, 
and is considered by most philosophers as the 
principal cause of that repulsion which takes 
place between the particles of bodies ; and to 
a similar cause the electric repulsion may be 
referred. 4thly. The pulse and perspiration 
of animals are increased by electricity as by 
the actual application of heat. 5thly. Ac- 
tual ignition is produced by the electric fluid. 
Thus it is a common experiment to inflame 
spirit of wine by the electric spark ; inflam- 
mable air is set on fire by the same means in 
the common electrical pistol; and even gun- 
powder may be exploded by a spark from 
a powerful conductor. Othly. Metals are 
melted by electricity ; and most inflammable 
substances are affected by it as by common 
fire, but in a weaker degree. 7thly. The 
light emitted by the electrical apparatus has 
all the properties of that which is emitted 
from the sun ; the composition differing in 
some respects, according to circumstances, 
as to the predominancy of certain rays, the 
light in different instances inclining to blue, 
red, white, &c. according to its intensity, 
gthly. The motion of light is exceedingly 
rapid, whether it is reflected or refracted ; 
in the same manner the electric fluid is found 
to move with almost infinite velocity, for it 
has been proved by experiments, that a cord 
1200 feet long has’ become instantly electric 
in its whole extent. The abbe N ollet lias 
communicated the electric shock to 200 per- 
sons at the same time, or at the least percep- 
tible instant. 
Notwithstanding these considerations, it 
must be confessed, that there arc some facts 
which seem to indicate that the electric fluid 
is not purely and simply the matter of heat 
or light unmixed with other substances : for 
1st, it has been observed, that the electric 
matter has the property of affecting the or- 
gans of scent, which is a property that be- 
longs neither to light nor heat. 
2dly. It is well known also, that an accu- 
mulation of caloric increases the fluidity of 
all bodies, and prevents them from- congeal- 
ing, whereas congealed fluids may be highly 
charged with electricity ; nor does it appear 
to have the smallest effect in increasing then- 
fluidity . 
3dly. Heat spreads in every direction, 
whereas the electrical fluid may be arrested 
in its progress by certain bodies, which, on 
597 
that account, have obtained the name of non- 
conductors. The Torricellian vacuum, on 
the contrary, affords a ready passage to the 
electric fluid, but is a bad conductor of heat. 
4thly. Whenever the matter of heat pene- 
trates bodies, it warms as well as expands 
them. The electric fluid does not produce 
these effects ; bodies, however long they may j 
be electrified, become neither hotter to the ; 
touch, nor more extended in dimensions. j 
Stilly. The singular property of adhering ; 
to certain conductors, without diffusing itselt ; 
to other substances, which may be even in 
contact with them, so observable in the dec- 1 
trical fluid, is a property not common to ca- 
loric or elementary (ire. Thus we have seen 
that spirits were kindled by an electrical spark 
drawn by a wire through the water ot the ; 
Thames ; and large pieces of iron wire have j 
been heated red-hot, while immersed in wa- 
ter, by an electrical explosion. 
Gthly. With respect to the identity of light 
and electricity, it should also be recollected, 
that light pervades glass with the greatest 
facility, whereas that substance is penetrated 
by the electrical fluid only in certain c ircum- 1 
stances, and with the utmost difficulty ; if, 
therefore, it should be admitted, that the ba- 
sis of the electric matter is radically the 
same with the matter of heat or light, it 
seems necessary (o admit also, that it retains 
some other matter in combination with it, of 
the nature of which we are as yet uninformed ; 
and it is probably this combination ot foreign 
matter which disables it, in ordinary cases, 
from penetrating glass. At present, how- 
ever, we know nothing for a certainty con- 
cerning the electrical fluid, but some of its 
effects. 
Electrical phenomena are produced by 
friction, and by communication. In general, 
bodies which electrify the best by friction, 
electrify the worst by communication (except 
glass in certain circumstances) ; and on the 
contrary, substances which electrify the best 
by communication electrify the worst by 
friction. We shall begin w'ith those experi- 
ments which gave rise to the principal tech- 
nical terms made use of in this science. 
If a dry glass tube is rubbed with a piece 
of dry silk, and if light bodies, as feathers, 
pith balls, &e. are presented to it, they will 
be first attracted and then repelled. The 
best rubber for a smooth glass tube is a piece 
of black or oiled silk, on which a little amal- 
gam has been spread: sealing-wax, rubbed 
with new and soft flannel, will produce the 
same effect. By this friction an agent or 
power is put in action, and this power is 
called the electrical fluid: a certain quantity 
of this fluid is supposed to exist latent in all 
bodies, in which state it makes no impression 
on our senses; but when by the powers of 
nature or of art, this equilibrium is destroyed, 
and the agency of the fluid is rendered per- 
ceptible to the senses, then those effects are 
produced which are termed electrical, and 
the body is said to be electrified. 
If a homogeneous body is presented to the 
excited tube, so as to receive electricity from 
it, and the electricity remains at or near the 
end or part presented, without being com- 
municated to the rest of the body, it is called 
a non-conductor or electric; but if, on the 
contrary, the electricity is communicated to 
every part, the body is called a conductor. 
or non-electric. A body is said to be insu- 
lated when it communicates with nothing 
but electrics, as when it is placed upon glass 
pillars, or a ball of wax or rosin, or any non- 
conducting substance. 
A conductor cannot be electrified while it 
communicates with the earth, either by direct 
contact or by the interposition of other con- 
ductors, because the electricity is immediate- 
ly conveyed away to the earth. 
A mutual attraction is exerted between a 
body in a state of electricity and all non- 
electric bodies, which, if not large and heavy, 
will pass rapidly through the air to the elec- 
trified body, where they remain till they 
have, by communication, acquired the same 
state, when they will be repelled. If an un- 
insulated conductor is at hand, it will attract 
the small body when electrified, and deprive 
it of its electricity, so that it will be again 
attracted by the electrified body, and repell- 
ed as before, and will continue to pass and 
repass between the two, till the electric state 
is entirely destroyed. 
The following is a list of electrics, and also 
of conductors, disposed according to the 
order of their perfection, beginning m each 
column with the most perfect of their class : 
thus glass is a more perfect electric than am- 
ber, and gold is a better conductor than 
, silver. 
ELECTRICS. CONDUCTORS. 
Glass of all kinds. All the metals in the 
All precious stones, following order : 
| the most transpa- Gold; silver; plati- 
; rent the best. na ; brass ; iron ; 
' Amber. tin ; quicksilver ; 
Sulphur. lead. 
I All resinous substan- The semi-metals. 
ces. Metallic ores, 
i Wax of all kinds: Charcoal. 
Silk and cotton. The fluids of the ani- 
l)ry external animal mal body. 
substances, as lea- Water, especially salt 
thers,- wool, and water, and other 
hair. fluids, except oil. 
Paper. Ice, snow. 
Loaf sugar. Most saline substan- 
Air when. dry. ces. 
Oils and metallic ox- Earthy substances. 
ides. Smoke, steam, and 
Ashes of animal and even a vacuum, 
vegetable substan- 
ces. 
Most hard stones. 
M. Achard, of Berlin, has proved by expe- 
riment, that under certain circumstances a 
body will become a conductor of electricity, 
which before was a non-conductor. The 
principal of these circumstances are the de- 
grees of heat to which the body is subjected. 
It must be observed, however, that elec- 
trics and non-electrics are not so strongly 
marked by nature as to be defined with pre- 
cision ; for the same substance has been dif- 
ferently classed by different writers : besides, 
the electric properties of the same substance 
vary according to changes of circumstances : 
thus a piece of green wood is a conductor ; 
and the same piece, after it has been baked, 
becomes a non-conductor ; when it is formed 
into charcoal, it again conducts the electric 
matter ; but when reduced to ashes, is im- 
pervious to it. Indeed, it might perhaps be 
generally said, that every substance is in a 
certain degree a conductor of this fluid. 
