Dr. Pearson’s Experiments , &c. 143 
let up into the convex part of the curved end of the tube, with 
the view of preventing fracture from the electrical discharge. 
The wire which passed through the sealed extremity was set 
in contact with a brass insulated ball ; and this insulated ball 
was placed at a little distance from the prime conductor of 
the electrical machine. The wire of the lower or open extre- 
mity, immersed in quicksilver, communicated by a wire or 
chain with the exterior coated surface of a Leyden jar, which 
contained about a square foot of coating ; and the ball of the 
jar was in contact with the prime conductor. 
The electrical machine consisted of two plates of 31 inches in 
diameter, and was similar to that of Teyler. It had the power 
of causing the jar to discharge itself 25 times in 15 revolutions. 
When the brass ball and that of the prime conductor were in 
contact, no air or gaz was disengaged from the water by the 
electrical discharges ; but on gradually increasing their dis- 
tance from one another, the position was found in which gaz 
was disengaged ; and which ascended immediately to the top 
of the tube. By continuing the discharges, gaz was discharged 
till it reached to nearly the lower extremity of the upper wire, 
and then a discharge occasioned the whole of the gaz to dis- 
appear, a small portion excepted, and its place was conse- 
quently supplied by water. 
From my own experience I should venture to affirm, that a 
more particular and more accurate account than that published 
is requisite, to enable the student, or even the proficient, to 
institute the above experiment with success. Hence, during 
the six or seven years which have elapsed since its publication, 
no confirmation has been published, except the experiment re- 
peated by Mr. Cuthbertson for my satisfaction, as related in 
