4* Experiments and Obfeyvations on the Galvanic Power. 



His firfl: attempts led him to compare Galvanifm with the old eledrlcity •, and he was 

 decidedly of opinion, that there was a fufficient diftinftion betwixt them to entitle the 

 former to the rank at lead of a new fpecies ; this obfervation my own experience has every 

 day confirmed, efpecially fince I have been able to give fo very confiderable a degree of 

 ftrength to the pile as I have latterly done. 



He attempted to ufe refin as a lining for a white iron cafe to the pile, in which, after 

 (landing for a (hort period, its power flopped ; and upon examining the pieces he found 

 the refin completely diffolved into a fubftanc? refembling turpentine, and forcibly drawn 

 betwixt the filver and zinc ; this (hows a violence of adtion which has never as yet been 

 obferved in Galvanifm, and may ferve as a caution to others againft ufing refinous fub- 

 ftances with the pile, at the fame time that it opens a field of inquiry with regard to its 

 effeds on that matter. 



His next and moil important obfervation was made on a moft fingular phenomenon, 

 which he perceived on the fides of the filver and zinc pieces which were in immediate 

 contaft, when ftrong pafteboard, moiftened with a folution of common fait, was ufed for 

 fetting up the pile : the pieces of pafteboard were of a polygonal form, and fmaller than 

 the metallic pieces; their figure was exadly ftamped in a black colour, not on the fides of 

 the pieces in contact with them, but on the dry metallic faces whicli were in contafl with' 

 metal only ; this very fingular appearance, which I had frequent opportunities of examining, 

 conveys an idea that fomething, circumfcribed in its a£lion by the figure of the moiftened 

 dlfks, and capable of penetrating through the pores of the metals and of oxidating them, 

 formed a conftituent part of the Galvanic fluid. 



He alfo obferved, what might be readily expetSed, that people advanced in years felt 

 the fmall (hocks of Galvanifm lefs readily than younger perfons ; but what was fingular, 

 they felt the ftrong (hocks more feverely ; this may throw fome light on the nervous fluid, 

 ■ and the change that it undergoes by age. 



He found that when the experiment of decompofing water was made in an open glafs, 

 that the water, although kept for a week after, unconne£ted with the pile, and a fufficient 

 quantity of fait had been added, to prevent all fymptoms of putrefadtion, yet continued 

 to emit a gas, and a mucous matter was precipitated from it, of a whitilh colour ; this feems 

 to have fome connection with an extraordinary liquor, procured by the ingenious Dr. 

 Moyfe, by evaporating the waftings of the pile ; but the account of which I by no means 

 wi(h to anticipate, as it is to be hoped that the learned Doctor will favour the world with 

 it himfelf. 



You will no doubt regret that fo truly philofophic an obfcrver (hould be loft to 

 mankind, and had you known the individual, you would have found that the powers of 

 his mind could only have been equalled by the virtues of his heart. 



I now, with diffidence, fubjoin an account of my own experiments* 



Being acquainted by obfervation, and by the experience of others, with the Galvanic 

 jower* of black lead, I attempted to form a range of plumbago crucibles, into a Galvanic 



apparatus^. 



