EFFECT OP GALVANISM IN METALLIC ARBORlZATlOWt, ] J/ 



and''*^t¥n?ftcoHon4 of wliich were unquestionably those of 

 t'Vjyjp^V'.'' This ex peri meut T repeated, employini^ a cylin- 

 dt^r bt" zinc instead o\' copper, and tiien the precipitation 

 6f* the copper ut the extremities of the brunches of silver 

 iv*i hi iith hi 6re ' kpeedy^ > 



"Hfence it evidently follows, 1st, that the arborization of Arborization a 

 metals, precipitated in the i)erfect state from their solvents, of'pafS"^ef. 

 is ftrfhied by superpbiition of their particles on one another: fected by gal- 

 2(Uy, that, since neither copper nor silver has of itself the ^^n'*"** 

 power of reviving the metal contained. in nitrate of copper, 

 these two metals were rendered capable of producing this 

 ieffcct only in virtue of a current of galvanic eiecUicity,-i;Qr^ ^x ^ ,:>!», 

 suiting from theirmutuai contact.'- \:^n*{ia!ftr.'a «r if*fii«?/rr Winant/^* , 

 The following is a farther proof of the truth of this Farther proof, 

 induction, Etftablish a communication between a plate of 

 copfWr^add a plaife'/of silver, both well polished, by one of 

 their extremities, and immerse the other two extremities in 

 a solution of my salt of copper, in such a manner that there 

 shall be the splice bf an inch between them. After leav-r,,^* tsxfjit ^ 

 mg them thus foiii- and twenty hours, the silver will be SilVrf cbaled 

 distinctly covered with a coat of cop|)er, and the other me- ^^"^ copper- 

 tal will be oxided*. To render this effect still more evident, 

 I place a few particles of nitrate or sulphate of copper, 

 slightly moistened, between a silver coin and a plate of 

 copper, both previously well cleaned with acid. I then tie 

 them, oi- compress them together, and leave them for a few 

 hours. On separating them, the ^lir^^tWi'lir be fouiid'^up^ 

 vered with a coat of metallic copper, very distinguishable 

 by its colour. It is a curioqs fact, that a salt with an An earthy or 

 earthv or aikaiiue'base may b^ eniployed instead of -a salt ^'^*'''"e salt 

 ^ ■.:. » , »- ■ . . ,' . , 1 .J -between the 



of copper; but in this case it is obvious, that the acid ot two metals 



the salt first takes nu ^ little of the copper, and then depo- ^^^^ answer. 



* iir'^WMWtohV'^o'flirst'oBs^Wl the Chemical action of two me- hisnotneces- 

 tti\\xh pla'tes Imiriers^d in solutions of different metals, supposed, that ^ary that the 

 oiie of them must possess the property of precii)itating the metal in so- J5Jf„'*s*|,JJJ,jj°'^' 

 solution, in order that the other might coat itself "'ith it al>;o by means precipitable 

 of a conducting power. The experimtnt I liave related howeter proves, by theoihef. 

 that this is not a necessary condition; and we may obtain in a few mi- 

 nutes the revival of zinc, by placing the sulphate of ♦his metal moist* 

 <^ned with water between a plate of zinc Sind a plate of copper. 



sits 



