19* On increasing the charging Capacity 
side coatings and believed that their charging capacity 
would be increased thereby. 
I embraced the first opportunity to try the effect of that 
discovery with single jars. 
Experiment I.— I took a very thick jar (which had 
been used to show the phenomena of voluntary explo- 
sions without breaking) twelve inches high; and the coat- 
ing nine inches; containing in the whole about one hun- 
dred and seventy-one square inches ; it was applied to 
the conductor of a plate electrical machine; and six turns 
of the plate caused a voluntary explosion to the coating : 
the state of the atmosphere not being very dry; it re- 
quired eight and twelve turns to produce a second and 
a third explosion : a fourth could not be produced ; but 
when cleaned and dried as before; six turns caused a 
voluntary discharge. 
Experiment II.— A slip of paper one inch broad was 
taken ; of sufficient length to fit round the outside of the 
jar when the two ends were pasted together: this was 
slipped on to its outside to about one inch from the coat- 
ing : the uncoated part being rubbed clean and dry; and 
applied to the machine; eleven turns of the plate produ 
ced a voluntary discharge to the outside coating. 
Experiment III. — The paper ring was then slipped 
down to touch the coating; and then applied to the con- 
ductor : no voluntary discharge could be produced; and 
when discharged in the common way; its power did not 
seem to be increased; — to prove which; 
Experiment IV.— The common discharging electro- 
meter (which is always fixed to the basement of my ma- 
chines) was used; to try to what distance the discharge 
could be made to pass from the knob of the conductor to 
the ball of the electrometer ; which w as found to be one 
inch and five-eighths. 
