150 hetter from ProfeJJot Pi£let of Geneva. 



than pure water, merely as better condu5lors. This faft he 

 alfo proves by direft experiments. 



On thefe three fundamental fafts he then builds his whole 

 fabric. Let the apparatus be a pile, a feries of cups, or a 

 trough, his theoretical pofitions anfwer equally well. He 

 explains, among many curious phagnomcna, why the Vol- 

 taic pile charges a large Lcyden jnr, by a fingle inllantaneous 

 contaft, much more than the eleftrical machine in the fame 

 circumftance. 



He thus transfers, from a pile of 100 or 200 couples, to a 

 very large Leyden jar, and even to a battery, by a fingle 

 contaft, which lads not above i-ioth of a fecond, the fame 

 degree of eleflrical charge which the elc£lrometer fliows to 

 exift in the pile, and the faculty of giving a (hock equally 

 llrong. Thofe experiments require the moft perfcft conti- 

 nuity in the conduclors; metallic chains mull therefore be 

 excluded from the circuit. 



The frogs and other animals put in motion after death by 

 what has been hitherto called the gai-vajiic injiuence, are in 

 his theory but mere elcArometers. He fliows, in particular, 

 that a half frog, difpofed in the common way, is almoft in- 

 dehnitelv fufceptible of mufcular contractions by merely in- 

 verting alternately its pofition relative to the direction of the 

 eleftrical current : that is, when blunted, for inftance, by a 

 number of difcharges paffing from the right leg to the left, 

 it recovers its whole fufceptibility if it be but half turned 

 round, fo as to reverfe the courfc the fluid takes; and this 

 repeatedly for a long while, till bordering on putrefadiion. 



A conimiilron chofen among the ableft eleftricians in the 

 National Inftituto, has been named to examine both the 

 theory of the learned profeflbr and the experiments on which 

 it is grounded. He intends to colleft fqon, iri one fingle 

 performance, the moft efl'ential fafts and inferences he has 

 publiflied at different times on the fubjeft ; and in the mean 

 time my friend Mr. De la Methcrie prepares for the Journal 

 de Vhyfique an account more circumftantial than the flight 

 Iketch I am now forwarding to you, rather fit, I confefs, to 

 excite than to gratify your curiolity. 



I am, &c. 



M. A. PiCTET. 



XXV. LetU 



