rOL. XLIV.] PHILOSOPHICAL TRANSACTIONS. 413 



power. He observed that by rubbing a glass tube, while standing on a cake of 

 wax, in order, as he expected, to prevent any of the electrical power from dis- 

 charging itself through him into the floor; contrary to his expectation, that 

 power was so much lessened, that no snapping was to be observed on another 

 person touching any part of his body. But if a person not electrified held his 

 hand near the tube while it was rubbing, the snapping was very sensible. After- 

 wards he met with an experiment of the same kind, in a treatise published by 

 professor Bose, intitled, Rccherches sur la cause et sur la veritable theorie de 

 I'Electricite, which that ingenious gentleman says, had given him great trouble 

 by its oddness. The experiment is, that if the electrical machine be placed on 

 originally-electrics, the man who rubs the globes with his hands, even under 

 these apparently favourable circumstances, gives no sign of being electrified, 

 when touched by an unexcited non-electric. But if another person, standing on 

 the floor, does but touch the globe in motion with the end of one of his fingers, 

 or any other non-electric, the person rubbing is instantly electrified, and that 

 very strongly. 



Muschenbroek's phial of water seems capable of a greater degree of accumu - 

 lation of electricity, than any thing we are at present acquainted with ; and we 

 see when, by holding its wire to the globe in motion, the accumulation being 

 complete, that the surcharge nms off^ from the point of the wire, as a brush of 

 blue flame. A method has been discovered here by a gentleman, Mr. Canton, 

 by which the quantity of accumulated electricity may be measured to great exact- 

 ness. The manner of measuring is this: when the phial is sufliciently electrified 

 by applying its wire to the glass globe, and which is known by the appearance of 

 the brush of flame at the end of the wire, as beforementioned ; hang a slender 

 piece of wire to the suspended gvm-barrel for this purpose detached from the 

 globes. On applying the wire of the electrified phial to that hanging to the gun 

 barrel, you perceive a small snap ; this you discharge by touching the gun-barrel 

 with your finger, which likewise snaps ; and thus alternately electrifying and dis- 

 charging, you proceed till the whole electricity of the water is dissipated; which 

 sometimes is not done, under lOO discharges. If you do not discharge the 

 electricity every time, the snaps from the wire of the electrified phial to the gun- 

 barrel are scarcely perceptible. In proportion to the number of strokes, you 

 estimate the quantity of the acquired electricity of the water. That you could, by 

 stopping the electricity, excite non-electrics; and, by accumulating their power, 

 make them exert more force than originally-electrics would at any point of time, 

 was that capital discovery of the late Mr. Gray; and is to be regarded as the 

 basis, on which all the present improvements of our knowledge in electricity are 

 founded ; and till which discovery, though some of the eflfects of electricity were 

 observed above 2000 years ago,* little progress was made. 



