[ sss 3 
prefent ltfdf in an infinite number of luminous, 
ilreams, of extraordinary beauty ; and, if you do not 
take care, you will be fmartly fhocked, as in the ex- 
periment of Leyden, by laying one hand upon the 
receiver, and touching with the other the plate of 
the air-pump. 
To prove, that, in the experiment of Leyden, the 
electrical virtue, or power of giving a fhock, does 
net rejftde only in the glafs, make the following expe- 
riment : 
EleCtrife a phial two thirds full of water ; potir 
this water into another thin phial, placed upon a 
•glafs {land ; plunge therein an iron wire, and at- 
tempt, while the phial is ill one hand, to drtw a 
fpark with the other ; it is certain, that, if this is 
done with a little readinefs, you will make the ex- 
periment of Leyden with this water §. Pofiibly 
you may not always fucceed with water ; but with 
mercury, under the fame treatment, it never fails. 
Whence proceeds the power of giving the diock to 
the fecond glafs, if it is not by means of the water, 
which it has received ? 
EleCtrife a bolt-head of glafs, void of air, and 
fealed hermetically ; you may make ufe of it for the 
experiment of Leyden, and you will fucceed. Is 
A a a a 2 there 
§ Some years ago I fhewed this experiment to feveral members 
of the Royal Society, and did not only therewith produce the ex- 
periment of Leyden, but by pouring the ele&rifed water into a 
bafon, held in one hand of an alfiftant ftanding upon cakes of wax, 
who, upon his prefenting a finger of his other hand to fome warm 
fpirit of wine in a fpoon, held in the hand of a perfon ftanding 
upon the floor, fet it on fire. I then copfider’d this experiment, as 
a proof of the ele&ricity being accumulated in the water. 
' W, Watfon, 
