ioa8 Dr. ingenhousz’s Experiments 
other non-concluding matter, upon which the faid me- 
tal plate is placed. 
This machine, invented by Mr. volta, a learned gen- 
tleman of Como, is certainly a valuable acquilition to the 
Eledi'ical apparatus. Once excited, it is for a long while 
ready to afford eledricity enough for all experiments 
which do not require a very great force; and it has the 
advantage of not being fo much affeded by damp wea- 
ther as the common machines with glafs globes, cylin- 
ders, difk, See. It is very eafily put in adion by a 
flight fridion with a dry hand, a piece of leather, a rough 
Ikin' of a hare, a cat, or fome other animal. It is as eafy 
to excite with this machine a negative as a pofitive elec- 
tricity. It has the advantage of being capable at almoft 
all times of affording at pleafure fuch a force of eledri- 
city as is wanted, even to fuch a degree, that the metal 
plate is no longer able to contain all the eledric fluid 
communicated to it; but throws it out every way, either 
upon the metal upon which the refinous cake is ufually 
fixed, or into the air: and this increafe of eledrical 
power is obtained by the eafieft means ; for inflance, by 
charging with the Eledrophore a coated phial, and plac- 
ing it afterwards upon the refinous cake itfelf, or upon 
the metal plate placed upon the refinous cake (provided 
the metal plate be lefs in circumference than the refi- 
nous 
