ON IG^LVANISM. , 121' 



The experiments by which M. Volta and others have en- Decompofition 

 deavoured to (hew that piles compofed of metals only afford ^^ ^.f^^ '" S»*- 



*^ n - f • I I vanilm afcribedL 



the galvanic fluid, are fo little demonitrative ot it, that they not to the aftioii 



feem to me equally illuftrative of the contrary ; and I believe of elearipity, 



that all galvanic piles muft, with the intervention of fluids, be^^^^^^ 



compofed of two metals, or other fuhfiances, which have an 



affinity, the one for oxigen and the other for hidrogen ; for 



water and other fluids made ufe of in galvanic piles, are de- 



compofed; and not, I conceive, as hath generally been ima-. 



gined, by the eledtricity of the metals ; but by the adion of 



affinities. For inftance, in a pile formed with zinc, copper, 



and water, the oxigen and hidrogen of the water having a 



ftronger affinity for the zinc and copper (the oxigen for the 



zinc and the hidrogen for the copper) than for each other, 



unite with them, the water being confequently decompofed, 



and the eledHric or galvanic fluid, which was contained in it, 



confequently fet at liberty. 



In fupport ipf this theory I* may alledge as fa6ts, that the firft Fuller explana- . 

 fliock from a galvanic pile is generally the ftrongeft, when J-!^^/'^**'" 

 the energy of the affinities is the greatefl; that for a repeti- 

 tion fqme interval of time is requifite, whilfl: the decompoti- 

 tion is taking place; that the metals in the pile aft, not ac- 

 cording to their quantities, but according to their furfaces— • 

 the greater thefe are, the greater being the quantity of water 

 adled upon; that the zinc is always oxidated, and the copper 

 (or filver) always aded upon by the hidrogen, being rendered 

 more brittle, &c. ; that any alteration in the arrangement of 

 the pile, which brings two pieces of the fame metal to the fame 

 fjratum of water, inftead of one piece of each metal (one to 

 ad on the oxigen and the other on the hidrogen), interrupts 

 the procefs, and, no decompofition taking place, there is no 

 eledric fluid produced; and it may alfo be added, that this 

 lafl is a fad which cannot otherwife be accounted for, 



I am not ignorant that a flream of the galvanic fluid from Objeaion, that 

 the pile, pafled through water, decompofes it; but it is no *^^ galvanic 

 proof, I prefume, that water contains none of this fluid, be- pofes water 

 caufe it is decompofed by a greater quantity than will chemi-*"^wered, 

 cally mix with it. If we pour a fmall quantity of water im- 

 pregnated with carbonic acid gas into lime-water, the lime is 

 precipitated, or compofed, the lime-water becoming turbid; 

 • but 



r 



