414 PHILOSOPHICAL TRANSACTIONS. [aNNO 1747, 



"ITie electrical aether is much more subtil than common air, and passes to a 

 certain depth through all known bodies. It passes most readily through metals, 

 water, and all fluids, except resinous ones; then animal bodies dead or alive, in 

 proportion as they are more or less wet; then stones, wood, and earths. It 

 passes to a certain thickness only through resins, dry animal substances, wax, 

 and glass. For this reason bodies are called electrics per se, or non-electrics; 

 not only for their rubbing the electricity from other bodies, but likewise as they 

 permit more or less of the electrical aether to pass through them. This aether 

 has not only the property with air of moving light substances, but it seems to 

 have another, and that is elasticity. 



That this fluid is more subtil than common air, is more particularly demon- 

 strated by its passing through several glasses at the same time; through any one 

 of which, though ever so thin, air cannot pass. It likewises passes through all 

 known bodies, except originally-electrics, and even through these to a certain 

 degree. Its elasticity is proved by its extending itself round excited electrics, and 

 excited non-electrics, to a considerable distance; as well as by its increasing the 

 motion of fluids. This is demonstrated by the experiment with a small glass 

 siphon where the elacticity of the electrical aether overcomes the attraction of 

 cohesion. The stream through this slender tube is most complete when the non- 

 electric is brought near, so as when the room is somewhat darkened, the stream 

 of water appears as a stream of blue flame, much like that from the blunt wire. 

 This stream is stopped, either by touching any part of the non-electrics in con- 

 tact with the globes, by placing the machine and the man who turns the wheel 

 on electrics per se, by which the current of the electrical aether from the floor to 

 the machine is prevented; or by removing the non-electric from the leg of the 

 siphon, by which the dissipation of the electrical aether from the excited non- 

 electric becomes general. So that we find, that though we can repel light bodies 

 from many parts of excited non-electrics at the same time; the whole force of 

 the electrical current is necessary, to drive off" so ponderous a fluid as water. 

 May we likewise not infer the elasticity of electrical aether, from the ingress of 

 the blue flame from the end of a blunt wire held near the axis of the wheel, or 

 any part of the wood-work of the machine, after the revolutions of the globes 

 are ceased? certainly we see an influx of electrical fire to all bodies, till their 

 determinejl quantity is restored. Is not the elasticity of this aether deducible 

 likewise from the violent shock we feel in our bodies in the experiments with 

 water? 



* Theophrastus, who lived above 300 years before the date of the Christian aera, takes notice of 

 amber and the lyncuriura attracting not only straws, and shavings of wood, but also tliin pieces of 

 copper and iron.— Orig. 



