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presently when in vacuo) or passing 1 from body to body. 

 A clear bottle full of air, instead of water, cannot be 

 electrified. But exhausted of air, it is electrified as 

 effectually as if it was full of water. Yet an electrical 

 atmosphere and ak do not exclude one another ; for we 

 breathe in it freely, and dry air will blow through it 

 without altering it at all. 



When a glass phial is electrified, whatever quantity of 

 fire is accumulated on the inner surface, an equal quantity 

 is taken from the outer. Suppose, before the operation 

 begins, the quantity of fire contained in each surface 

 is equal to twenty grains : suppose at every turn of the 

 globe one grain is thrown in : then after the first stroke 

 there are twenty-one within, nineteen only without : after 

 the second, the inner surface wiil have twenty-two, the 

 outer but eighteen : and so on, till after twenty strokes, 

 the inner will have forty, the outer none. And the 

 operation ends : for no power or art of man can throw 

 any more on. the inner surface, when no more can be 

 taken from, the outer. If you attempt to throw more 

 iu, it is thrown back through the wire, or flies out in 

 cracks through the sides of the phial. The equilibrium 

 cannot be restored in this phial, but by a communication- 

 formed between the inner and outer surface, by some- 

 thing external touching both the outer and the wire 

 which communicates with the inner surface. If you 

 touch these by turns, it is restored by degrees : if both, 

 at once, it is restored instantly. But then there is a 

 shock occasioned by the sudden passing of the fire 

 through the body in its way from the inner to the outer 

 surface. For it moves from the wire to the finger, (not 

 from the linger to the wire, as is commonly supposed.) 

 Thence it passes through the body to the other hand, 

 and so to the outer surface. 



The force with which this shock may be given is far 

 greater than one would conceive, ft will kill tats, hens, 

 or even turkeys, in a moment: others that are not quite 

 killed,, it strikes blind, It will give polarity to a fine 



