Experiments toith a New EURrical or Galvanic Apparatus. 185 



top. The ele<Slricity of the filver was then tried a number of times, by preclfely the fame 

 procefs as before, and it exhibited an equal degree of intenfity, but it was minus or ne- 

 gative. In one of thefe experiments, I certainly faw the fpark at the time of completing 

 the circuit, and afterwards with the fame pile, when I was exprefsly looking for it. But 

 it is lefs neceflary to dwell on thefe fafts, as the ftronger combinations have exhibited this 

 €ffe6l with much greater perfpicuity. 



The decompofition of water, and oxidation of metallic wire, gave birth to a variety of 

 fpeculationS and projedls of experiments. Among others it became a queftion, what 

 would be the habitude of metals of difficult oxidation. Two wires of platina, one of 

 which was round, and one fortieth of an inch in diameter, and the other nearly of the fame 

 mafs, but flatted to the breadth of one twenty-fifth of an inch, were inferted into a fhort 

 tube of if of an inch in fide diameter. When placed in the circuit, the filver fide gave a 

 plentiful ftream of fine bubbles, and the zinc fide alfo a ftream lefs plentiful. No turbld- 

 nefs nor oxidation, nor tarnifli appeared, during the courfe of four hours continuance of 

 this operation. It was natural to conjecture, that the larger ftream from the filver fide 

 was hydrogen, and the fmaller oxigen. Thick gold leaf was tried with the fame effedls. 

 A wire of brafs was tlien fubftituted inftead of one of the flips of gold. When the brafs 

 was on the minus, or filver fide, the two gafes were extricated for two hours, without 

 oxidation as before ; but when the brafs was, by reverfing the tube brought to the plus fide^ 

 it became oxided In the fame manner as if both the wires had been brafs. When the flips 

 of gold were long fubjedted to this a£tion, the extremity of the flip communicating with 

 the zinc, acquired a coppery or purplelfh tinge, which was deepeft near the end. Whether 

 this arofe from oxidation of the gold, or of the copper, of which gold leaf contains about a 

 feventieth part, cannot from this experiment be decided. 



The Cmple decompofition of water by platina wires without oxidation, offered a means of 

 obtaining the gafes feparate from each other. With this intention, Mr. Catlifle's pile 

 of thirty-fix was combined with my two fets of fixteen repetitions. Kis pile was 

 built with the zinc uppermoft, and mine In the reverfe order ; fo that by conne£l- 

 ing the upper plates the whole conftituted one range, and the communications could be 

 made from the bottom of the one to the bottom of the other. The two platina wires were 

 made to protrude out- of two feparate tubes, each containing a little water, and through 

 the oppofite corks of each were pafled copper wires of communication, Thefe tubes were 

 flightly greafed on the outfide to prevent their becoming damp ; and in this ftate the extre- 

 mities, armed with the platina, were plunged in a Ihallow glafs vefl"el of water, in which two 

 foiall Inverted veflels, quite full of water, were fo difpofed, that the platina of one tube was 

 beneath one veflfel, and the platin* of the other tube was beneath the other, the diftance 

 between their extremities being about two inches. The copper wires of thefe tubes re- 

 Ipeftively were made to communicate with the extremities of the intire pile of fixty-eight 

 fcts. A cloud of gas arofe from each wire, but moll from the filver, or minus fide. Bub- 



VoL. IV.— July 1800. Bb bles 



