mere ContaB of conditBlng SuhJ!ances. 29I 



hitherto known ? Does it not aft inceflantly, and without 

 interniilTion ? And, in the iaft place, is it not capable of 

 giving every moment fhocks of greater or iefs ftrength, ac- 

 cording to circumftances — fhocks which are renewed by 

 each new touch, and which, when thus repeated or con- 

 tinued for a certain time, produce the fame torpor in the 

 limbs as is occafioned by the torpedo, &c. ? 



I fliall now give a more particular defcription of this ap- 

 paratus and of others analogous to it, as well as of the moft 

 remarkable experiments made with them. 



I provide a few dozens of fmall round plates or difks of 

 copper, brafs, or rather filver, an inch in diameter more or 

 Iefs (pieces of coin for example), and an equal number of 

 plates of tin, or, what is better, of zinc, nearly of the fame 

 fize and figure. I make ufe of the term nearly, becaufe great 

 precifion is not neceiTary, and the lize in general, as well as 

 the figure of the metallic pieces, is merely arbitrary : pare 

 only muft be taken that they may be capable of being con- 

 veniently arranged one above the other, in the form of a co- 

 lumn. I prepare alfo a pretty large number of circular 

 pieces of pasteboard, or any other fpongv matter capable of 

 imbibing and retaining a great deal of water ormoifiure, with 

 which they muft be well impregnated in order to enfure fuc- 

 cefs to the e.'^periments. Thefe circular pieces of pafteboard, 

 which I (hall call moiftened difks, I make a little fmaller thai% 

 the plates of metal, in order that, when interpofed between 

 them, as I fliajl hereafter defcrlbe, they may not projedl be-p 

 yond then), 



Having a\\ thefe pieces ready in a good ftate, that is to 

 fay, the metallic difks very clean and dry, and the non-me- 

 tallic ones well moiliened with common water, or, what is 

 mxich better, fait water, and (lightly wiped that the moiiture 

 may not drop off, I have nothing to do but to arrange them, 

 a matter exceedingly fimple and eaiy. 



I place then horizontaiiy, on a table or any other (land, 

 one of the metallic pieces, for example one of filver, and over 

 ti>c (irft I adapt one of zinc } on the fecond I place one of 

 tiie nioifteued dill;s, then anothej- plate of filvt;r followed 

 ■immediately by anoiher of zinc, ovtir which I jilace another 

 V p 3 of 



