NATURE OF OXIGEN, HIDROGKN, CALORIC, &C. g^ 



have never in any experiment been made fenfible to us? Is it 

 not philofophical to refer phenomena to caufes which are ob- 

 je6ls of our fenfes, rather than to account for them by agents 

 which are merely hypothetical? 



Under certain circumftances water is converted into two Develonsment 

 airs, which airs have peculiar properties; in the galvanic ^^'i^nfej-ences.^ 

 periment we are made acquainted with no other agent but 

 thofe powers which are elicited by the particular arrangement 

 of metals, and thefe powers we are made fenfible of; they 

 produce different effedts on various fubftances, and therefore 

 I contend that thefe powers are different agents: for the fame 

 powers under the fame circumftances ftiould produce the fame 

 effedts. The zinc fide of the galvanic arrangement produces 

 vital air, whilft the copper fide produces inflammable air. — 

 Does it not appear from this experiment that there are other 

 caufes befides caloric that give aeriform elaflicity to bodies? 

 And do not the two powers of the pile here feem to be real 

 principles? Each of (hem produces a real and decided effed 

 on water. At all events we have not in this experiment any 

 reafon for afferting that water is a compound body, formed of 

 two diftind and folid fubftances, oxygen and hydrogen. I do 

 not mean at prefent to inquire whether negative eleftricity be 

 a mere negation or not. We know that it is as much a caufe 

 of repiilfion as what is called pofitive eleftricity, and that in 

 experiments of a different kind from the one we are now confi- 

 dering. When a fubftance has in one infiance been clearly 

 proved to be formed of certain principles, it is confiftent with 

 philofophical accuracy to refer in all other inftances to the fame 

 principles as the caufes of the produ6lion of fuch fubftance. 

 Inflammable air therefore is water rendered aeriform by nega- 

 tive electricity or galvanifm; and vital air is water rendered 

 aeriform by pofitive ele(5tricity or galvanifm. This is nearly 

 the enunciation of the faft, and I contend that in this, and in 

 all the reafonings refpecling water and fire, we ha\^e no occa- 

 fion for the two hypothetical principles, oxygen and hydrogen. 



In the above experiment with the pile of Volla, it appears The effed n;n 

 that it is not caloric which caufes the elaftic aeriform ftate of""'''=^''3':alonc. 

 either the vital or the inflammable air, at leaft we are not made 

 fenfible of it. li^ it were caloric that proceeded from the two 

 wires of the pile, why fbould each wire uniformly produce 

 the fame air, and one different from the other ? There fliould 



be 



