J 10 



ON THF. G ALVA NIT PlIKNOMEKA. 



Experiment of- 

 fered in proof. 

 A feries of 

 glafles, with the 

 metals and wa- 

 ter, give a cer- 

 tain electric in- 

 tenfityandfrjockj 

 but on adding 

 fait to the water, 

 the intenfity is 

 the fame, though 

 the fhock. is 

 much greater. 



The apparatus 

 charges a large, 

 battery almoiV 

 witontaneoufly. 



In order to eftablifh (his ^ and render it evident to fuch 

 as have found a difficulty in admitting it, that the electric force 

 or tenfion is, if not entirely, yet very nearly the fame, whe- 

 ther the wet layers be moiiiencd with pure water or with a 

 faline folution, though the difference in the ihock is fo great, 

 I have frequently made the following experiments, of which 1 

 have fpoken to you, and which I would have ftiewn to you, 

 if I had been provided with the requifite articles. I take 30 

 cups or drinking glaffes, with which I conftruct one of thefe 

 apparatufes which I term a crown of cups, putting into them 

 a fufficient quantity of pure water, and cauting them to com- 

 municate, the firfr. with the fecond, the fecond with the third, 

 and fo on fucceflively to the lait, by means of metallic wires, 

 which terminate at one end in a plate of copper, and at the 

 other in one of zinc, and are all turned in the fame direction. 

 The apparatus being confirucled in this manner, I try its 

 electric force, by canting the fir ft of the cups to communicate 

 with the ground, and applying the condenfer to a piece of 

 metal which is partly immerfed in the lait : this condenfer, 

 when I afterwards withdraw it, and feparate one of its difes 

 from the other in the proper manner, and without delay, gives 

 rtie 40, 60 degrees, and more, according to its condenfmg 

 force. I alfo try the fhock in the moft advantageous manner, 

 and find that it is very flight : after having well afcertained 

 both the degree of the electricity and the weaknefs of the 

 ihock, I add a pinch of fait to each cup, and repeating the 

 proofs, I find that the electricity has not been at all increafed, 

 the condenfer giving me ftill only 40 or 60 degrees, as before ; 

 but the iliocks are incomparably ftronger. 



There are many other experiments, which I have defcribed 

 to you verbally, and which I would willingly have performed 

 before you, had I not been in want of the requifite apparatus. 

 I informed vou— at which you were much aftonifhed, and 

 Mr. Pjctet ftill more fo — that with one apparatus I charge a 

 Leyden phial, whatever its capacity may be, and even a large 

 battery; that I charge them in an inftant, or, to fpeak more 

 accurately, in lefs than a twentieth part of a fecond, and aU 

 molt to the fame degree as the apparatus itfelf, namely, to 

 about one degree of tenfion, if the apparatus be compofed of 

 60 pairs ; to two degrees if it contain 120, &:c. ; — that I am 

 then able to draw r , by the help of the condenfer, a ftrong fparjc 



fron> 



