338 Experimeiifs in Galvanic Elecirtckj. 



Mr. Anthony Carlille, having been favoured with a pcrufat 

 of this paper by the very refpeftable Prefident of the Royal 

 Society, the Right Hon. Sir Jofeph Banks, Ba;rt. foon after^ 

 in conjuntSlion with Mr. Nicholfon, began to repeat the ex- 

 periments of M. Volta, and obtained fimihir refults. Very 

 early in this courfe, the contacts being made fure by placing 

 a drop of water upon the Upper plate of the pile, Mr. Car- 

 lifle obferved a diferigagement of gas round the conducing 

 wire. This gas, though minute in quantity, feeitied to Mr. 

 Nicholfon to have the fmell of hydrogen when the wire of 

 communication was fted. This, W'ith fomc other fa6ts, led 

 him to propofe to break tho circuit by the fubftitution of a 

 tube of water between two wires. Accordingly, a brafs wire 

 tlirough each of tw^o corks was inferted at the oppofite ends 

 of a giafs tube about half an inch in diameter, filled between 

 the corks with water : the diftance between the points of the 

 wires in the water, was about an inch and three quarters. 



" This compound difcharger was applied fo that the ext«rnaV 

 ends of its wire were in contaft with the two extreme plates 

 of a pile of thirty-fix half crovl'tts with the correfpoiident 

 pieces of zinc and palieboard. A fine llream of minut-e bub- 

 bles immediately began to flow from the point of the lower 

 wire in the tube, which communicated with the filver, and 

 the oppofite point of the upper wire became tarniflied, firft 

 deep orange, and then black. On revei-fing the tube, the 

 gas came from the other point, which was now lowefl, while 

 the upper, in its turn, became tarniflied and black. Re- 

 verting the tube again, the phenomena again changed their 

 order. In this ftate the whole was left for two hours and 

 a half. Tlie upper wire gradually emitted whitifli filmy 

 clouds, which, towards the end of the procef;', became of a- 

 pea-green colour, and hung in perpendicular threads front 

 the extreme half inch of the wire, the water being rendered 

 femi-opaque by what fell off, and in a great part lay, of a 

 pale green, on the krvver furface of the tube, which, in this 

 difpofition of the apparatus, 'was inclined about forty degrees 

 to the horizon. The lower wire, three quarters of an inch 

 long, cnnfliantly emitted gas, except when another circuit, or 

 Complete wire, Jvas applied to the apparatus; during which 



time 



