Oh the Caufe of the Galvanic Phenomena. 341 



their powers were not reftored.— i/. I have proved by many experiments * that water, de- 

 prived of air, is capable of attradting it from the fpirit of turpentine when the laft is in con- 

 taft with the atmofphere. The galvanic pile a£ts in fpirits of turpentine for a great length 

 of time, and nearly as well as in the atmofphere, the water between its plates being con- 

 (lantly fupplied with air from the fpirits. It a£ts but for a fliort time in fpirits of wine, on 

 account of the combination of this fluid with its water. — e. After a pile had ceafed to &Gt in 

 hydrogen, its powers were uniformly reftored by a momentary immerfion in very diluted 

 marine acid. They were likcwife reftored, and rendered more intenfe than in the atmof- 

 pher cbymomentary immerfion of the pile in diluted nitrous acid, though they continued 

 to be exerted for a fliort time only, i. e. till the acid was decompofed or faturated. 



6. T/}e Power of AEl'ion of the Pile ofVolta appears to he proportional to the Power of the cott' 

 dttSling fluid Stihflance betiveen the double Plates to oxidate the Zinc. 



This feems fufficiently proved from the fa£ls in the following feftions. The zinc oxi- 

 dates, lefs rapidly in' nitrous gas than in atmofpheric air, and lefs rapidly in atmofpheric air 

 than in oxygen : and the power of aflion of the pile as known by its evolving gas from 

 water is greater in oxygen than in atmofpheric air, and greater in atmofpheric air than 

 in nitrous gas. The power of the pile to decompofe water, and to give the fhock is won- 

 derfully increafed after it has been dipped in marine acid, and ftill more increafed after it 

 has been dipped in weak nitrous acid; and thefe bodies only enable the zinc to oxydatc 

 itfelf more rapidly. A feries of plates, in which the oxidating condu£ling fluid was ftrong 

 nitrous acid, a£led, as will be feen hereafter, infinitely more powerfully than any other com- 

 bination ; fo that it would fcem that the power of a pile is not inuch conneded with the 

 evolution of hydrogen from water. 



7. Conch ftons. 



Of two phenomena, or of two feries of phenomena, we can only affirm that the one is 

 the caufe of the other when it uniformly precedes it, and when their modifications are con- 

 nedted. But it appears from all the foregoing fadts, that the galvanic pile of Volta a£ls only 

 when the conducing fubftance between the plates is capable of oxidating the zinc ; and 

 that in proportion as a greater quantity of oxygen enters into combination with the zinc in 

 a given time, fo in proportion is the power of the pile to decompofe water, and to give the 

 fliock greater. It feems therefore reafonable to conclude, though with our prefent 

 quantity of fafts we are unable to explain the exaft mode of operation, that the oxidation 

 of the zinc in the pile and the chemical changes connected with it zxtfome how the caufe of 

 the eledrical eflfefts it produces. 



• Thefe experiments will be hereafter detailed, 



8. Of 



