A OL. XLVII.] PHILOSOPHICAL TRANSACTIONS, 237 



rations, nor from the circumambient air, Mr. W. had heretofore, in his com- 

 munications on this subject, endeavoured to evince. He had shown, that elec- 

 tricity is the effect of a very subtil and elastic fluid, occupying all bodies in con- 

 tact with the terraqueous globe: and that every where, in its natural state, it is 

 of the same degree of density; and that glass and other bodies, which we deno- 

 minate electrics per se, have the power, by certain known operations, of taking 

 this fluid from one body, and conveying it to another, in a quantity sufficient to 

 be obvious to all our senses ; and that, under certain circumstances, it was pos- 

 sible to render the electricity in some bodies more rare than it naturally is, and 

 by communicating this to other bodies, to give them an additional quantity, and 

 make their electricity more dense; and that these bodies will thus continue until 

 their natural quantity is restored to each ; that is, by those, which have lost part 

 of theirs, acquiring what they have lost; and by those, to which more has been 

 communicated, parting with their additional quantity. Both one and the other 

 of these is, from the elasticity of the electric matter, attempted to be done from 

 the nearest non-electric: and when the air is moist, this is soon accomplished, 

 by the circumambient vapours, which here may be considered as preventing in a 

 very great degree our attempts to insulate non-electric bodies. But these matters 

 he had copiously treated of in his former communiaitions on this subject. 



If therefore the beforementioned principles are true, and if the electricity is 

 not furnished by the globe in its rotation, nor by the air, it ought to be visible 

 in the vacuum of the before-described glass tube, in its ingress to the frame of 

 the electrifying machine, if this machine, and the man who turns its wheel, are 

 supported by electrics per se; and if, during this operation, the electricity, as 

 fast as furnished, is taken off by a bystander, or otherwise, from the prime con- 

 ductor; as under these circumstances the vacuum is the only passage open to its 

 progress, and from its elasticity the electricity should protrude itself through it. 

 And from experiment this is the case; for on a piece of wire being connected 

 with the end of the long brass rod, or with the brass cap at the upper extremity 

 of that tube, and the other end of the wire fastened to any part of the frame of 

 the electrifying machine, and this last put in motion, the electrical coruscations • 

 are seen to pass as before, from one of the brass plates contained in the tube to 

 the other ; and to continue, unless the air insinuates itself, as long as the ma- 

 chine is in motion. If, under these circumstances, the hand of a person stand- 

 ing on the floor be brought near the sides of the glass, the comscations will 

 direct themselves that way in a great variety of forms, extremely curious to 

 behold. 



This experiment therefore, in which the electricity is seen, without any preter- 

 natural force, pushing itself on through the vacuum by its own elasticity, in 

 order to maintain the equilibrium in the machine, which had lost part of its 



