200 
EPPKRIMENTS IN ELBCTRICITV. 
two bodies moving simultaneously in opposite directions in the 
electrical circuit. 
Experiment 5. 
The two pith-balls were put exactly in the middle of the 
interval, as the single pith-ball w'as in exjjerirnent 3, When 
the jar was discharged, no perceptible motion was observed in 
either of the pith-balls. 
The preceding experiments at the time of their discovery, 
were repeatedly performed in order to verify the results j and 
the interval in the circuit has since been varied from two to 
six inches in length ; experiments 1 and 2 have been made 
even with an interval of seven inches j and, in every instance, 
the results have been uniformly the same as above stated, when 
the strength of the charge has been proportioned to the in- 
creased or diminished distance forming the interval in the 
circuit. 
With respect to the cause or causes producing the move- 
\ 
merits of the pith-balls in experiments 1, 2, and 4, I shall, at 
present, offer no opinion } it is obvious, however, to observe, 
that if these experiments had been known either to the elec- 
tricians of a former period, who devised and supported, or to 
those of the present period, who have adopted and defended, 
the hypothesis of two. fluids moving in opposite directions 
during the discharge of the Leyden jar ; that they would have 
eagerly brought them forward as strongly favouring that hy- 
pothesis ; and the remarkable circumstance, that the balls in 
experiments 3 and 5 are not affected by the discharge, would 
undoubtedly have been -Considered as giving additional proba- 
bility to the hvpothesis, if not confirming its truth. 
Having satisfied myself with regard to the certainty and 
constancy of the effects produced in the foregoing experiments, 
I wished to ascertain what effects would ensue when the charge 
of the jar was sulliciently powerful to pass over the interval 
in circuit with an explosion : they were found to be as follow : 
When a single pith-ball was placed either at the positive 
or 
