534 TH E INTELLECTUAL RISE IN ELECTRICITY. 



ether, much more subtle than common air, and passing to 

 a certain depth through all known bodies. It has the 

 property of air, of moving light objects, and is likewise 

 elastic, this last fact being shown by its extending itself 

 around excited electrics, by its increasing the motion of 

 fluids, by the apparent influx of electrical fire to all bodies 

 and by its giving violent shocks to the human frame. 



With this ether all bodies are normally charged. If, 

 however, a body be excited, then the normal conditions 

 are disturbed, so that the ether in the nearest unexcited 

 non-electric tends, by its elasticity, to move to the excited 

 body where it accumulates. In so doing it carries light 

 bodies with it, which accounts for electrical attraction. 



Applying this idea to an electrified Leyden jar held in 

 one hand of an observer, who touches with the other the 

 metal gun-barrel on which it is suspended by its inserted 

 wire, Watson maintains that, on the explosion which fol- 

 lows, the man (nearest conductor) instantly parts with as 

 much fire from his body as is accumulated in the water of 

 the jar and in the gun barrel; the fire rushing violently 

 through one arm to the water, through the other to the 

 barrel. Then as much fire as the man has lost is imme- 

 diately and with equal violence replaced from the floor of 

 the room. Hence, and for both reasons, the shock. This 

 flux, he further says, may be prevented, and its effects are 

 not seen, when the glass containing the water is too thick, 

 or if the man stand on an insulator, or if the points of con- 

 tact between his (conducting) hand and the jar which it 

 holds are fewer. The last limitation, it may be observed 

 in passing, proved suggestive; for Dr. Bevis, a member 

 of the Royal Society, promptly showed that the greatest 

 number of contact points would be obtained by coating the 

 exterior of the jar with sheet lead or so-called tin foil. 

 This suggestion was adopted, as it was found that a person 

 who merely touched this coating with a small wire ob- 

 tained as strong a shock as if the whole hand rested against 

 the exterior of the uncoated bottle. 



