1044 -Dr. ingenhousz’s Experiments 
tive part of a charged phial upon it, or by many other 
ways) the contrary muft happen, viz. the eleCtric fluid 
of the metal plate, finding a kind of vacuum upon the 
refin cake, rufhes upon it, and thus leaves its oppofite 
extremity in a negative ftate. 
A conducting body, having its natural quantity of 
eleCtric fluid, being brought near this metal plate, gives 
it a fpark, which fpark the metal plate retains as an addi- 
tional quantity. If the metal plate be afterwards fepa- 
rated from the cake, it muft retain this additional quan- 
tity which it has received from the approaching body ; 
becaufe the refinous cake being, from its nature, more 
tenacious of the ftate of electricity acquired than the me- 
tal, remains thereabout in the fame condition as it was 
before the metal plate was placed upon it ; but the metal 
plate, having acquired an additional quantity in the time it 
was placed upon the cake, carries with it this quantity, and 
muft therefore return from the cake in a politive ftate. 
This confirms what I faid before, that in the firft cafe 
the cake of refin does not quit readily the eleCtric fluid 
which it had acquired ; and, in the fecond cafe, does not 
fteal from the metal plate the eleCtric fluid which it had 
loft. 
What happens to the metal plate placed upon the re- 
finous cake happens alfo to the metal upon which the 
refinous cake is commonly fixed; but the reverfemuft 
take 
