2b8 KvpemnSnis on the Chemical ProduSlloit 



meter, each furniflied with a fliding; elcftronieter to regulate 

 the lirenglh of the fpark received fiom them. 



Exfc-r. 4. Ilavuig a wire of fine filver, -j-to of an inch in 

 diameter, I coated the middle of it, for 2 or 3 inches, with 

 fealincr-wax, and, by cutting through in the middle of the 

 wax, e.xpofed a feftion of the wire. The two coated extre- 

 mities of the wire, thus divided, were immerfed in a folution 

 of fulphatc of copper placed in an eleftric circuit between 

 the two conduiSlors; and fparks, taken at -r'g- of an inch di- 

 ftance, were pafled by means of them through the folution. 

 After i.00 turns of the machine, the wire which communi- 

 cated with (what is called) the negative conduftor had a pre- 

 cipitate formed on its furface, which, upon being burnifhed, 

 was evidently copper ; but the oppoiite wire had no fuch 



coating. 



Upon reverfing the direftion of the current of eleftricity, 

 the order of the phaenomena was of courfe reverfed ; the 

 copper being Hiortly rediflblved by afiiitance of the oxidating 

 power of pofitive elcftricity, and a limilar precipitate formed 

 on the oppofite wire. 



Ex-per. 5. A fimilar experiment made with gold wires -^-^ 

 of an inch diameter, in a folution of corrolive fublimate, 

 had the fame fuccefs. 



The chemical agency, therefore, of common eleftricity is 

 thus proved to be the fame with the power excited by che-- 

 mical means ; but, fince a difference has been obferved in 

 the comparative facility with which the pile of Volta decom- 

 pofes water, and produces other eflefts of oxidation and de- 

 oxidation of bodies expofcd to its aAion, I have been at fome 

 pains to remove this difiiculty, and can at Icaft produce a 

 verv clofe imitation of the galvanic phsenomena by common 

 eleftricity. 



It has been thought nccelTary to employ powerful ma- 

 chines and large Levden jars for the dccompolition of water; 

 )t)ut, when I confidered that the dccompofition muil depend 

 on dulv proportioning tlie ilrength of the charge of electricity 

 to the'qnantitv of water, and that tlie quantity expofed to its 

 action at the furface of communication depends on the extent 

 of that furface, I hoped that, by reducing the furface of com- 

 inuuication, the dccompofition of water might ije cffefted by 

 fmallcr machines, and with lefs powerful excitation, than 

 have hitherto been ufed for that purpofc; and in this hope 

 I have not been difappointed. 



Exper. 6. Having procured a fmall wire of fine gold, and 

 given it as fine a point as I could^ 1 infcrted-it into a capil- 

 lary 



