and Galvanifni. l.^q 



furface of the quickfilvcr with the end of the fine wire, the 

 coinbuftion was fo flrong, that it difperfed on all fides fparkles 

 whichh.id the appearance of thoufands of rays, conftituting 

 very fine funs of ieveral inches diameter. By flowlv lower- 

 ing the wire as it confumes, this fpcclacle may be continued 

 at |)leafure. 



The No. [6. wire, of —^ inch diameter, fncceeds nioft 

 certainly; but wire o{ —,.- inch makes a more brilliant tliow. 

 W^hen it is too thick to burn, the fparks form fpots of o.xid« 

 on the bright furface of the i]uickfilver. 



The end of a platina wire, of about -,--— inch diameter, was 

 melted into a globule by the difcharge. The fparks given by 

 the wire of communication, when tlie latter was large enough, 

 exceeded -'« inch diameter. 



They thought much depended on a proper degree of hu- 

 midity in the fubftance? iuterpofed between the n^etals ; and 

 they advife a cold faturated folution of muriate of ammoniac 

 to be ufcd, in preference, for this purpofe. 



The intenfilies of two cohnnns containing an equal num- 

 ber of plates appeared equal by the eleftrometer, although 

 their diameters were fo different as i and 5 mches. On 

 taking feveral repeated Ihocks from each, their powers in this 

 refpecl feemcd alfo to be alike. In the fufion of wire, how- 

 ever, the larger diameter had an evident advantage; which 

 was attributed to the greater velocity of the current of elec- 

 tricity flowing through the metal. 



By diminifhiug the diameter of the humid condu6>or3 be- 

 tween the plates, the force of the pile was lelfcned in propor- 

 tion. On fubiiitutiug water, or folution of fea fait, to that 

 of fal-ammouiac, the fame pile which before melted four 

 inches of wire could not be made to redden a fingle line. 

 Whence arifes the fuperior efleft of the ammoniacal fait? 

 Is it becaufe it oxidates the metals more? It appeared, in- 

 deed, that the aftion of this pile diminifhed in proportion as 

 the oxidation of the metals did i"o : but, on the other hand, 

 from the refult of feveral comparative experiments with the 

 fiilphunc, nitric, and muriatic acids, they conclude that the 

 prompt oxidation produced by thcfe means is fo far from in- 

 crealinu, ihar. it rather leflens the power of the pile in all re- 

 fpects. Neither did ammoniac, which was alfo tried fepa- 

 raiely, produce an elfeCt at all comparable to ihiii of the neu- 

 tral fait *. The oxidation of the metals, therefore, although 



it 



* The author does not fay whether fi>Iiitioii of pure aiT)(noniac,or of the 



caitxjriHte, was ufed. In cithci- c.ifc, it cleats ii"t app' ar to us that it couid 



be aj'phcd io fuih a device nf conceittr^tiun m to atToid a fair cernparii'va 



L » of 



