120 



©N GALVANISM* 



XII. 



On Gakanifm. In a Letter from Ra. Thickness^, Efq. 



SIR, 



To Mr. NICHOLSON. 



Wi^an, Sept, 20, 1804. 



On the caufes 

 which retard 

 difcovery. 



xILTHOUGH the produ6Hon of the elearic fluid by the 

 galvanic pile has never yet been fatisfaclorily accounted for, 

 it appears to me fomewhat eafy to be explained, from a con- 

 fideration of the principles of chemiftry. This, I am aware, 

 is a very bold opinion from a man who is a mere dabbler in 

 philofophy ; but as it muft be allowed that the ableft philofo- 

 phical inquirers and experimentalifls have been guilty of ex- 

 traordinary overfights, I truft my prefumption is excufable. 

 When an ardent mind has once entered a wrong path in pur- 

 fuit of knowledge, it is too intent upon the objeds before it ^ 

 to turn afide, and too anxious to proceed to be induced to 

 look back. Thus chemifts fifty years ago thought they ob- 

 tained earth from water, becaufe they omitted to weigh the 

 veflek in which they made their experiments ; and thus, per- 

 haps, the profeflfors of galvanifm at the prefent day, being of 

 opinion, as I believe they all are, that the electric fluid pro- 

 ceeds from the metals, devote little of their attention to the 

 fluid employed in the pile, confidering it almoft as a mere 

 eondudlor. Nothing can be more obvious to a chemift now 

 than the neceflity of weighing the matter he fubjects to expe- 

 riment, and alfo theprodu6t; yet the difcovery alone of this 

 necefllty overturned the opinions, and falfified the wifdom, 

 of all the previous ciiltivators of the fcience, and led to the 

 modern theory of chemiflry and its improvements ; an omifllon 

 how trifling in itfelf to keep men (philofophers too) poking 

 in the dark for ages ! 



Water, we are told, is compofed of certain parts of oxigen 

 and hidrogen ; but, a$ to form thefe bodies, from a ftate of 

 ^fed of oxigen, g^s at lead, into water, it is necetfary to pafs lan eiedric 

 fpark through, or rather irito them (no matter whether the 

 procefs of formation be combuftion or not), and as water owes 

 its fluidity to heat, the matter of heat and the eledric fluid 

 being probably the fame, or modifications of the fame body, 

 I think it reafonable Xo atlume that water is compofed of 

 oxigen, hydrogen, and tlie ekSlric Jluid, 



The 



Argument or 

 inference that 



pole 



hidrogen, 



eledlricity 



and 



