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TlE word ELECTRICITY fignifies, ingeneral, ,he

~ITeas

of a very fu"tile Anid maner, dilFmot in

it<propenies from every other f1nid we are

ae~nainted

"i,h. This fluid is e.pable of u,li,ing wi,h almon e

ve<

bo.ly,

bUI unites more readily wi,h fome panicular

b~dies ,han wi,h o,hers: itsmOlion is amazingly

~uick,

regul' l,d

peculiar laws, anel produces a

van

variety

of liogular phenomena, the principal of whieh Olall be e–

oUllleraled in

tllIS

anicle.

As \'le are eOlirely igooram of the oature of lhe elee–

trical fluid, il is impolf,ble

defioe it but by its prioei –

pal propenies: that of rcpclling and anraaiog light bo–

dies, is one of themon remarkable. The aneicms \Vere

only

ae~u,inted

with this

pr~perty

in amber. William

Gdben,

nalive of Colchener, and phyfieian al Lon–

don, io his tre'tife

Magm/(,

in the year 1600, was

lhe hrll pafon who difeovered, thal (¡dpllur, wax, re–

finous fubllanees, glafs, aod preeious nones, \Vhen dried

and rubbed alinle, \Vere eodowed \Vid1 the fame propeny

of amaaing aod repellmg flraws and other lighl fubflao–

ces. Sir Franeis Bacon, in his phyfiologieal remaios,

gives a

eat~logue

of elearical bodies; bUI il dilfers in

oOlhing worth mentioning from Ihal of Gilbert. Mr

Boyle, about the rear 1670, made fome addition to Ihe

catalogue of elearie fub!!aoees; but all his experimems

on this fubjea relate ooly to a few eireumnances meod–

ing the fimple propeny of clearie anraaion: he had ne–

ver feen the elearie light, and little imagined wh.t ano–

oilhiog elfeas would be afterwards produced by tltis woo–

derful power.

Cotempor31ywith Mr Boyle was Otto Guerieke, bur–

gom,lb of

Ma~debulg,

and inl'enlOr of rhe air-pump,

\\'howas likewife une of lhe r,rfl impro1'ers of elearieity.

He made hise'paiments with a gMe of fulphur, \Vhich

mouoterl on an axis, aod \Vhirled ir in a wooden

frame, rubbing it "' Ihe fame rime with his hand . He

fir~

difeovered. Ihar a body once attraaed by an exeited

eleél rie \Vas repelled by it, and not attraéled ag;,in t,lI it

had been rouehed by lome othcr body : that bodi,s im–

merged in eleanc atmofpheres are rhemfdves elearilicd:

th.ar

rhreads l'lfpended within

fmall dinanee of his ex–

eired globe, IVere often reptlled by his finger brollghr

orar Ihem: rhar a fearher, repdlcd by the globe, al",ays

turned the f,me face towards it, like Ihe moon wirh re–

freé!

Ihe eanh: . nd thar rhe exell"ion of his r,lobe

produced both light antl fOIlOd, IhOllgh in a I'cry iocror,fi·

dmble degree.

mllrh finer dcarie light was after–

"'uds ohfrrvcd hv Dr Wal l. aod ao aceount of i¡ \Vas

~ul

hlhed in ,he -j'h'¡o((¡rl,ic;'¡ Ttan'aaioos: Dr V,rall

j,,k< \Vife elOmrms the lighl and rhe crackling of his ex-

CI"d .

ml,.r

11>

thender and li"hrening,

Sir lIa. e Nc""on, io

1 r. 7í~

WilS Ihe firfl \Vho difeo–

I'C-"d

11131

exciten gl.lfs :lIl rilllt d

li~ht ' bodics

on the lide

('ppofi'(' ro tl"r (¡n . 1,lrh it

IV]'

rllhbed.

Afrer Gdhert, Hoyle, and Ouo Guerieke, Mr Hawkef.

bee, in his Phylieo-mechanieal Experiments, publ:lhed

in Ihe ycar

17°'1,

dillingUllbed hlmfd f by his experi–

menrs and d,lCl>vems In clea. ieity. He lid! difcovered

lhe deélric p"lVer

(lf

gl"fs, rh, hghr proeeeding (rom ir

and rhe noile oceafion,d by ir, tOgerher with aI'ariely of

phxnomena ,e1aurog tO tI,arie am.tlton and repulfion:

Indeeu liule Was ad(led

his obfervations, tilllhe Meo–

very of a pi

liS

and minus eleélricity b), Dr

,t;oo and

Dr Franklin abutl! the ye" r746, and the

f~lIher

il–

luflration of thal doarine by Mr Clnron.

From the yeal 1730 to rhe 1746, the IVriters on

elearieilYare fo numerous, and their expcrimcnrs fo Ola–

ny and various, that a v(¡llIme lVould be i01"/lieitnt for

their hinory.

\Ve

/hall therefore endeavour, in thefrJl

place,

1'0

give a lhon and eonneaed vie\V of the natere

and pr illciples of e1eélrieity, ro far as they hll'e hi,heno

been unfolded, wirhom mentioning the perruns

whom

we are indebted for any panicular difeoocry: And, in

the

fml/d

place, GlI'eadefeription of eI"élrieal maehi"es.;

with a feleaion of a fe\V of the mon eurious and ufeful

experiments, whieh the reader may ealilr

underlla~d

af–

ter having made himfelf aequainted lVitl1 thegeneral prin–

cipies.

has been alTerted, that all bodies, provided they be

heared tOa eenJIOdcgree, and rubbed for a long time,

wdl difeover themr.h·es

be polT,Oed of Ihe property

of auraéling and repelling Ilght fub!lan ces. Howe –

ver, merals of all kiods, although e"er fo much heat–

ed, or ruhhed, or Fo!iOICd, nel'Cr difeover Ihe Ica(l

figns of clrarical am,aion; aod wn(e<luenIly

are

ex–

c' pted froOl rhe gener:!

rul~,

as \Vell as water 3nd olher

fluids, which eaunot be fubjelled to rhe neeell'ary treat–

men!. Although mofl bodles, by being heared and rub–

bed, difeover more or lefs

01'

deilrieal

ama~ion

; yel, as

fome of thempolfefs rhis propeny in a more eminenr de–

grec, and with lefs labeur, this cireuml!anee has

rugg~(!ed a dil'ifioo of bodies inro IWO c1aOes, aceordiog as they

are more or Icfs fu:ceplible of elearicir)'.

The r,rn

cbf~

eomprdlends thole bodies \Vhich rmire

and eollea the el,élrieal mamr mofl e,fily. and iu g,eal–

ell

~udntily,

afler being a linle rubbed and hcalcd: thcfe

bodies are ealled

r!,{/,

¡CJ,

IIOn ron.l,,{/orJ;

(eeh as,

l. Di' monds of all kinds; ,he ruh)', the f.1pphire, the

emerald, Ihe opal, ,he amcthyr., tI,e IOpaz, the beryl,

the granar, rock eryn, l,

(:jc.

Glals, and alll'i"ified bodies, enamels

all co·

lours. pOJcc!atn, glars of anrimony, of lead,

éc.

Hal!,ms, relins

all kincl<,

Il'ax.

ec.

!lituminous bodics, fulritur, 2mber, afrhaltuOl,

6c.

Ce" ,in aoimal prcduélions;

filk, fwhers, 11'001,

1" lir~,

ao,1 briOh,

ce.

l'he ft.rond daIS

comprcherd~

Ihefe bod:es Il'hieh ei–

lher do no,

al! eoll:a

th~

c1célrica! maller by fri,qion,