4 25 
E L E e T R l C I T Y. 
We have feen, that the transference of eledtricity is 
dcfultory, and that the change made in the eledtric ftate 
of the communicating' bodies is always confiderable. It 
appears to keep fome fettled ratio to the whole eledtric 
power of the body. When the form of the parts where 
the communication takes place, and other cii cumftanees, 
remain the fame, the transference increases with the fize 
of the bodies; and all the phenomena are more vivid in 
proportion. When the conductor is large, the fpark is 
very bright, and the fnap very loud. This fnap alone 
feems to indicate fome material agent. I-'t is occafioned 
by a fonorous undulation of the air, or of fome elaftie 
fluid, which fuddenly expands, and as fuddenly collapfes 
again. But fuch is the rapidity of the undulations, that 
when it is made in clofe veffels it does not , exift long 
enough, in a very expanded ftate, to affedt the column of 
water, fupported in a tube by the elafiicity of the air, for 
the purpofe of a delicate thermometer or barometer ; 
juft as a mufket-ball will pafs through a loofe hanging 
flieet of paper without caufing any fenfible agitation. 
The fpark is accompanied by intenfe beat, which will 
kindle inflammable bodies, will melt, explode, and cal¬ 
cine, metals. It alfo produces fome very remarkable 
chemical effedts. It calcines metals even under water or 
oil ; it renders Bolognan phofphorus luminous ; it de- 
compofes water, and makes new compofitions and decom- 
pofitions of many ga ft form fluids; it affedts vegetable 
colours; it blackens the calces of bifmuth, lead, tin, luna 
cornea; it communicates a very peculiar frnell to the air 
of a room, which is diftindt from all others; and in the 
calcination of metals, it changes remarkably the fmells 
with which this operation is ufually accompanied; it af¬ 
fects the tongue with an acidulous tafte ; it agitates the 
nervous fyftem. When we compare thefe appearances 
with fimilar chemical and phyfiological phenomena, 
which naturalifts never hefitate in afcribing to the adtion 
of material fubftances, transferable from one body, or 
one ftate of combination, to another, we can fee no greater 
reafon for hefitating in afcribing the eledtric phenomena 
to the adtion of a material fubftance; which we may call 
a fluid, on account of its connected mobility, and elcdric 
fluid, on account of its diftinguifhing effedts. 
Having taken this comp'rehenfive view of the ancient 
and’prefent ftate of the fcience of eledtricity, it would 
be abfurd to traverf'e the wild and barren waftes of thofe 
authors who have fet up unfounded theories and fanciful 
hypothefes ; or to bewilder and perplex the reader with 
the uninterefting and defuitory controverfies which have 
been the confequence, merely to arrive by circumlocu¬ 
tion at thofe legitimate fadts which are now eftablifhed 
by the teft of experiment and rational demonftration. 
Thofe who delight in the clear and convincing language 
of mathematical difcuffion, may fee the Franklinian the¬ 
ory lifted through all the moft ftriking features of elec¬ 
trical phenomena, in the work of M. iEpinus, of the 
imperial academy of St. Peterfburgh ; as well as in thofe 
of our iiluftrious countrymen, the Hon. Mr. Cavendifh, 
and earl Stanhope. We are convinced that the refiilts of 
their labours, clearly and methodically arranged, cannot 
but be moft fatisfadtory and pleafing to the bulk of our 
readers, becaufe they will thereby obtain an ample know¬ 
ledge of all the phenomena, without the coft of that la¬ 
bour and time which it is not always convenient to be¬ 
llow : and thefe phenomena having been moft accurately 
and neatly clalled in the Inftitutes of Natural Philofop'ny, 
recently publilhed by the Rev. Dr. Enfield, we (hall 
avail ourfelves of that mode, and ftate them as follows ; 
From what has been premifed, we are warranted to con¬ 
clude, i. That the earth, and all bodies with which we 
are acquainted, contain a certain quantity of that exceed¬ 
ingly elaftie fluid, which is called the dtdricfluid .-—This 
certain quantity, fuppofed to belong to all bodies, may be 
called their natural (hare or ftate ; and fo long as each 
body contains neither more } . nor lefs, than this quantity of 
Vol. VI.,No. 36}. 
the eledtric fluid, it lies dormant, and produces no effedt. 
2. When a body becomes poftefled of more, or lefs, than 
this natural quantity, it is inftantiy cledrifed, and is ca¬ 
pable of exhibiting appearances which are aferibed to the 
action cf dcdricity. —This equilibrium could never be 
difturbed-, or, if it were difturbed, would be immediately 
reftored, and therefore be infenftble ; but that fome bo* 
dies do not admit the pafiage of the eledtric fluid through 
their pores, or along their furfaces, though others do, 
3. When therefore a body has acquired an additional 
quantity of eledtric matter; or loft a part of what natu¬ 
rally belonged to it, and is at the fame time furrounded 
by bodies through which it cannot pafs, it mu ft remain in 
that ftate, and is thence faid to be inflated. —The doc¬ 
trine which refillts from thefe definitions, and from the 
fadts previoufly ftated, will be found exemplified in the 
following propofitions : 
I. Tlte eledtric fluid, being excited, becomes percep* 
tible to the fenfes.—Let a glafs tube be rubbed with the 
hand, or with a leathern cufhion ; the eledtric fluid being 
thus excited, will attract light fubftances, and give a 
lucid fpark to the finger, or any metallic fubftance, 
brought near it. The glafs tube is the elcdric, and all 
thofe bodies which are capable, by any means, to pro¬ 
duce fuch effedts, are alfo eledrics. The hand, or any 
other body that rubs an electric, is called the rubber. 
Refpedting the theory of electricity, there are two dif¬ 
ferent hypothefes, one that there is only one fluid, and 
the other that there are two. Dr. Franklin’s hypothefts 
is the former, and depends on the following principles : 
1. That all terreftrial bodies are full of the eledtric fluid, 
2. That the eledtric fluid violently repels itfelf, and at- 
tradts all other matter. 3. By exciting an eledtric, the 
equilibrium of the eledtric fluid contained in it is destroy¬ 
ed, and one part contains more than its natural quantity, 
and the other lefs. 4. Condudting bodies, connedted with 
that part which contains more electric fluid than its na¬ 
tural quantity, receive it, and are charged with more than 
their natural quantity; this is called pofltive eledtricity; 
if they be connedled with that part which has lefs than 
its natural quantity, they part with fome of their own, 
and contain lefs than their natural quantity ; this is called 
negative electricity. 5. When one body pofitively and 
another negatively electrified are connedted by any con¬ 
dudting fubftance, the fluid in the body which is pofi¬ 
tively eledtrified rufties to that which is negatively elec¬ 
trified, and the equilibrium is reftored. Thefe are the 
principles of pofltive and negative eledtricity. The other 
hypothefts is, that there are two diftindt fluids, fuggefted 
by M. D11 Faye, upon his difeovery of the different pro¬ 
perties of excited glafs, and excited refins, fealing-wax, 
&c. The following are the principles of this theory : 
1. That the two powers arife from tv/o different fluids 
which exift together in all bodies. 2. That thefe fluids 
are feparated in non-eledtrics, by the excitation vf elec¬ 
trics, and from thence they become evident to the fenfes, 
they deftroying each others effedls when united. 3. When 
feparated they rufh together again with great violence, 
in confequence of their ftrong mutual attradtian as foon 
as they are connedled by any condudting fubftance. Thefe 
are the principles of vitreous and reflnous eledtricity._ But 
the theory is unfounded. 
II. 'The eledtric fluid paffes eafily along the furfaces 
of fome bodies ; whilft other bodies do not convey it : 
the former are called ccndudors, the latter non-cohdudors, 
or e/edrics. —The metallic cylinder being fixed upon glafs 
fupporters, and placed near the eledtric machine, will, 
by means of pointed wires, receive the eledtric fluid from 
the glafs cylinder, and the fluid will be diffufed over the 
whole furface of the metallic cylinder, from' w hence it 
cannot pafs through the glafs fupporters which are elec, 
trie, but may be conveyed away by any metallic or other 
conduding fubftances, brought near, or into contadl with 
it. This metallic cylinder is the prime condudor. 
5 A. AIT- Som.fi 
