^P •V CHlMtCAL IFffNlTY. 



8U(?h mifttlificatlons of attraction and repulsion are am«ns^ 



the tnostobvioiw pbenoinena of electricity, and thn!«e t))nt 



first p:ave,ori<i;in to this science. But after what has been 



said, it must appear impossibl»i to consider difference of 



electrical state a» identical with the principle of attraction. 



Neither do I think it could be seriously contended, that 



ficnilarity of eU'ctrical state is identical with the principle of 



repulsion; as this would, at least, involve the opinion, that 



similarity of electrical state, whether positive, or negative, 



is identical with the canse of increased temperature; au 



opinion I, by no uieims, feel ujyself called upon to confute. 



Supposition of Possibly, however, it was never meant, that difference of 



minute d I fftr. electrical state is identical with the principle of chemical 

 enctj in the . . . . . 



elettrica! »tate ^f "^*-'tion ; but tliat there exist m:nute djfterences m the 



of dissimilar electrical states of the particles of dissimilar kinds of mat- 

 ' ^ ' ter,-— that ^nch differences are not destroyed by contact, — 



and .that, althougli they are not sufficient sensibly to af- 

 fect tbe vibrations of the pendulurw. they rnay yet so mo- 

 dify the principle of attraction, as to give rise to the pheno- 

 mena which favour the idea of elective affinity. This is 

 certainly the least objectionable form tht- hypothesis can 

 assume. The supposition, however, that dissimilar bodies 

 preserve different electrical states, i» in opposition to ana- 

 logy ; since we invariably [)erceive a tendency in bodies to 

 acquire similar electrical btates, as far, at least, as our most 

 cteiicate instrumeUtti inform iis; and as this law holds t9 

 e»ery measurable difference, it would surely be unphiloso- 

 phical not to consider it as absolute, and without exception, 

 P.irtiel«j miRhi Were we to adopt the th»*ory of Dr. Franklin, it mij^ht 

 hiATe different appear t^ follow from many facts, tlmt dissimilar bodiea 

 eteclridty* ^**ve different capacities for the electric fluid ; but tlvis 

 would surely atford no stronger argument in favour of the 

 pt>inion, that bodies exist in different electrical states, than 

 might be drawn from their having different capacities for 

 caloric, in nupport of au opinion, that they have naturally 

 different temperatures. The hypothesis proposed by Mr. 

 Davy cannot, therefore, be admitted,' until it shall have 

 been proved, that it is capable of explaining, in the most 

 satisfactory manner, the phenomena on accotint of which it 

 wan astumed; and that these phenoD.ena are inex) Liable oa 



any 



