[ 6o 3 
that they had contradled no eledricity after they had 
been agitated in the manner defcribed above. Some- 
times I dipped them in turpentine, and obferved that 
no part of it was found flicking either to the brafs 
rods themfelves, or to any part of the table betv/ixt 
them and the place where the light bodies had been 
laid. I even found that the explofion of a battery 
made ever fo near to a brafs rod did not fo much as 
difturb the equilibrium of the eledlric fluid in the 
body itfelf : for when I had infulated the rod, and 
hung a pair of pith balls on the end oppofite to that 
near which the explofion pafTed, I found that the 
balls were not in the leafl moved at the time of ex- 
plofion, which they would have been, if part of the 
eled:ric fluid, natural to the body, had been diiven, 
though but for a moment, towards the oppofite end. 
I alfo obferved, that the effedl was the fame, when 
the explofion was made to pafs through one of the 
knobs of the infulated rod. This lateral force was 
evident through thin fubflances of various kinds in- 
terpofed between the explofion and the bodies re- 
moved by it, as paper, tin-foil, and even glafs j 
for when fome grains of gunpowder were put into a 
thin phial, clofe flopped, and held near the explofion 
of a battery, they were thrown into manifefl agi- 
tation. 
I therefore think it mofl probable, that this lateral 
force is produced by the expulfion of the air from the 
place where the explofion is made. For the eledlric 
matter makes a vacuum of air in its pafTage j and 
this air, being difplaced fuddenly, gives a concuflion 
to all the bodies that happen to be near it. Hence 
the removal of the light bodies, and the agitation 
com mu- 
