152 Dr. Pearson’s Experiments and Observations 
It seemed as if the electrical discharge had kindled the oxy- 
gen and hydrogen gaz of the decompounded water, by flying 
from the bottom of the wire to the brass funnel ; so that the 
fire returned into the tube where it passed through the gaz. 
Or the combustion might be occasioned by a chain of bubbles, 
reaching from the brass dish to the surface of the water in the 
tube, which was set on fire in its ascent, and thus produced 
combustion of the whole of the gaz of decompounded water. 
That this phaenomenon was from the combustion here sup- 
posed, was in some degree proved by finding that the mixture 
of hydrogen gaz and atmospherical air, under the same circum- 
stances, was kindled in the same manner. 
Experimentu. With a double plate electrical machine, 24 inches 
in diameter, and a similar apparatus to that in the last experi- 
ment, 14600 discharges produced, at least, one-third of a cubical 
inch of gaz. While I was measuring with a pair of compasses 
the quantity of gaz produced, the points of them being in con- 
tact with the part of the tube occupied by gaz, I was again 
surprised, on the passing of a discharge, by an illumination of 
the whole tube, and the rushing up, with considerable commo- 
tion, of water, to occupy about two-thirds of the space filled 
by gaz. 
The residuary air was found, as in the former experiment, 
to be rather worse than atmospherical air. 
It was concluded that the points of the compasses had at- 
tracted electrical fire from the wire to the sides of the glass, 
and thereby kindled the hydrogen and oxygen gaz of de- 
compounded water. But to determine this question, I intro- 
duced into the same tube a mixture of one measure of oxygen 
and two measures of hydrogen gaz, to occupy nearly the same 
