LI. Electrical experiments, made in pursuance of those by Mr. Canton, dated Decem. 3, 1753; with explanations by Mr. Benjamin Franklin, Communicated Mr. Peter Collinson, F. R. S LI. EleBrical Experiments, made in fuance o f thofe by M r . Canton, dated Decem. 3 , 1753 ; Explanations by M r . Benjamin Franklin, Communicated M r . Peter Collinfon, F. R . S. # Philadelphia, March 14, 1755. Principles. Read Dec. 13, I , T T "^ L edric atmofpheres,that flow round 175S’ 1 > non-eledric bodies, being brought near each other, do not readily mix and unite into one atmofphere, but remain feparate, and repel each other. This is plainly feen in fufpended cork balls, and other bodies electrified. II. An eledric atmofphere not only repels another eledric atmofphere, but will alfo repel the eledric matter contained in the fubflance o f a body ap­ proaching i t ; and without joining or mixing w ith it, force it to other parts o f the body, that contained it. T his is fhewn by fome of the following experi­ ments. III. Bodies eledrified negatively, or deprived of their natural quantity of eledricity, repel each other, (or at lead appear to do fo, by a mutual receding) as as well as thofe eledrified pofitively, or which have eledric atmofpheres. This is fhewn by applying the negatively charged wire of a phial to two cork balls, fufpended by filk threads, and by many other experiments. Prep a- D ow nl oa de d fr om h tt ps :/ /r oy al so ci et yp ub li sh in g. or g/ o n 05 A pr il 2 02 1 [ 30. ] V reparation• F ix a taffel o f 15 or ao threads, 3 inches long, at one end o f a tin prime condu& or; (mine is about f feet long, and 4 inches diameter), fupported by filk lines. L et the threads be a little dam p, b u t not wet. Experim ent I. P a fs an excited glafi tube near the other end o f the prim e conductor., fo as to g iv e i t J'ome , and the threads w ill d i v e r g e . Becaufe each thread, as well as the prime conduc­ tor, has acquired an elaftic atmofphere, w hich re­ pels, and is repelled by, the atmofpheres o f the other threads: if thofe feveral atmofpheres would readily m ix, the threads m ight unite, and hang in the m id­ dle o f one atmofphere, com m on to them all. Rub the tube afrefh, and approach the prim e conductor therewith, cr o f sways, near that , but nigh enough to give fparks j and the threads w ill diverge a little more. Becaufe the atmofphere o f the prime conductor is preffed by the atmofphere o f the excited tube, and driven towards the end where the threads are, by w hich each thread acquires more atmofphere. W ith d ra w the tubey and they w ill clofe as much. T h e y clofe as m uch, and no more, becaufe the atmofphere o f the glafs tube, not having m ix’d w ith the atmofphere o f the prime conductor, is w ithdraw n intire, D ow nl oa de d fr om h tt ps :/ /r oy al so ci et yp ub li sh in g. or g/ o n 05 A pr il 2 02 1 [ 3°2 ] intire, having made no addition to, or diminution from, it. Bring the excited tube under the tu ft o f ,, and they w ill clofe a little. T hey clofe, becaufe the atmofphere o f the glafs tube repels their atmofpheres, and drives part o f them back on the prime conductor. W ithdraw it, and they w ill diverge as . For the portion of atmofphere, which they had loft, returns to them again. Experiment II. E xcite the glafs tube, and approach the prime con­ ductor with i t yholding it acrofs near the oppofite end, to that on which the threads , at the di- ftance o f $ or 6 inches. Keep i t there a f e w condsy and the threads o f the tajfels w ill . W ithdraw it, and they w ill . T hey diverge, becaufe they have received eledtric atmofpheres from the eledtric matter before con­ tained in the fubftance o f the prime condudtor ; but which is now repelled and driven away, by the atmof­ phere o f the glafs tube, from the parts o f the prime condudtor, oppofite and neareft to that atmofphere, and forced out upon the furface o f the prime con- dudtor at its other end, and upon the threads hang­ ing thereto. W ere it any part o f the atmofphere o f the glafs tube, that flowed over and along the prime condudtor to the threads, and gave them atmofpheres (as in the cafe when a fpark is given to the prim e condudtor, from the glafs tube), fuch part o f the tube’s D ow nl oa de d fr om h tt ps :/ /r oy al so ci et yp ub li sh in g. or g/ o n 05 A pr il 2 02 1 [ 3°3 ] tu b e’s atmofphere w ould have remained, and the threads continue to diverge; but they clofe on w ith­ drawing the tube, becaufe the tube takes w ith it its own Atmofphere, and the electric m atter, w hich h ad been driven out o f the fubftance o f the prim e co n d u d o r, and formed atmofpheres round the threads, is thereby perm itted to return to its place. Take a /p a r k fr o m the prime conductor, near the threads, when they are diverged as before, and they w ill clofe. F o r by fo doing you take away their atmofpheres, compofed o f the eledric m atter driven out o f the fubftance of the prim e condudor, as aforefaid, by the repellency o f the atmofphere o f the glafs tube. By taking this fpark you rob the prim e condudor o f part o f its natural quantity o f the eledric m a tte r; w hich part fo taken is not fupplied by the glafs tube, for w hen that is afterwards w ithdraw n, it takes w ith it its whole afmofphere, and leaves the prim e con­ d u d o r eledrifed negatively, as appears by the next operation. Then w ithdraw the tube, and they w ill open . F o r now the eledric matter in the prime conduc­ tor, returning to its equilibrium, or equal diffufion, in all parts o f its fubftance, and the prim e con­ d u d o r having loft fome o f its natural quantity, the threads conneded w ith it lofe part o f theirs, and fo are eledrifed negatively, and therefore repel each other, by P r . I I I . Approach the prime conductor w ith the tube near the the fame place as a t firjl, and they w ill clofe . Becaufe D ow nl oa de d fr om h tt ps :/ /r oy al so ci et yp ub li sh in g. or g/ o n 05 A pr il 2 02 1 [ 3°4 ] Becaufe the part o f their natural quantity o f elec­ tric fluid, which they had loft, i£ now reftored to them again, by the repulfion o f the glafs tube forcing that fluid to them from other parts o f the prim e conductor: fo they are now again in their natural ftate. W ithdraw it, and they w ill open . For what had been reftored to them is now taken from them again, flowing back into the prime con­ ductor, and leaving them once more eleCtrifed nega­ tively. Bring the excited tube under the , and they •will diverge more. Becaufe morfc o f their natural quantity is driven from them into the prime conductor, and thereby their negative ele&ricity increafed. ^Experiment III. fh e prime conductor not being , bring the excited tube under the taj, and the threads w ill diverge. Part of their natural quantity is thereby driven out o f them into the prime conductor, and they become negatively eleCtrifed, and therefore repel each other. Keeping the tube in the fam e place w ith one , attempt to touch the threads w ith the finger o f the other hand, and they wiU recede fro m the . Becaufe the finger being plunged into the atmo- fphere of the glafs tube, as well as the threads, part of its natural quantity is driven back through the 8 -hand D ow nl oa de d fr om h tt ps :/ /r oy al so ci et yp ub li sh in g. or g/ o n 05 A pr il 2 02 1 [ 3°5 ] hand and body, by th at atmofphere, and the finger becomes, as well as the threads, negatively eledlriled, and fo repels, and is repelled by them . T o con­ firm this, hold a flender light lock o f cotton, tw o or three inches long, near a prim e condudtor, th at is eledtrified by a glafs globe, or tube. You will fee the cotton ftretch itfelf out towards the prime con­ ductor. A ttem pt to touch it w ith the finger o f the other hand, and it will be repelled by the finger. Approach it w ith a politively charged wire o f a bot­ tle, and it will fly to the wire. Bring near it a n e­ gatively charged wire o f a bottle, it will recede from th at wire in the fame manner, that it did from the fin g er; w hich demonftrates the finger to be nega­ tively eledtrifed, as well as the lock o f cotton fo fituated. LII. E x tr a B o f a L e tte r concerning E leB ri- city, fro m M r . B. Franklin to Monf. D e- hbard, inclofed m a L e tte r to Peter Collinfon, F. R . S. Philadelphia, June 29, 1755. Read Dec. 18, o u defire my opinion o f Pere Bec- JL caria's Italian book. I have read it w ith much pieafure, and think it one o f the b eft pieces on the fubjed:, that I have fcpn in any lan- guage. Yet as to the article o f water-fpouts, I am not at prefent o f his fentim ents; though I m uft own w ith you, that he has handled it very ingenioufly. M r. Collinfon has m y opinion o f whirlwinds and Vql. 4P« R r water- D ow nl oa de d fr om h tt ps :/ /r oy al so ci et yp ub li sh in g. or g/ o n 05 A pr il 2 02 1