^llCllEtorCAt AFFINITY. f/ft 



any known, nncl ]*»ss exceptionable principle. I shall en» 

 deavoiir to determine how far Mr. Duy\ 's proposition briiij^« 

 with it these recouiiueuchitions; and would her« observe, 

 that tlrt following ar<:^un)ents will equally apply, whether it 

 be held, that the principle of clieinical attraction is iden* 

 Xical with dilference of electrical state, or, ihat the principle 

 of chemical attraction is moditied by dilfereijce of electricdl 

 •tate. ; . . r 



Mr, Davy '^ gpecujation rests entirely on the correct neei Certain sub- 

 «f hia position, relative to the •* changes and transitions by ^e au*racred bv 

 ., electricity." He states, not as an hyjxnijesis, but as a gene- posUivt,other« 

 ,^ jal exprestiion of fa6t, that ** hidrogeii, the alkaline tub* ^^ '^'fcU ^* 

 litaiiCes, the metaU, and certain metallic oxidcpi, are attracted 

 by negatively clcctriticd nitttallic surfaces; and repelled by 

 positively electritied metallic gurfacci; and contrariwise, 

 that oxiw^eu and acid substances are attracted by positively 

 electritied metallic surfaces, and repelled by negatively , ^ 



electrified metal'ic surface**; and that these attractive aa4 *'^*"^'* '*^*^^ 

 repulbive forces are aulHciently energetic, to destroy or tui»# 

 pend the visual operation of elective affinity*. 



To determine, whether Mr, Davy's statement be correct, but this not, 

 I selected one, from each of the classes of substances enu- ^^^^J* ^^ 

 merated in the preceding p&rtigraph : viz. borucic a^^id, 

 barytes, and gold-leaf^ and 1 found, that the metal and 

 the earth were attracted us powerfully by an insulated 

 metallic ball> electrified by glass, ag by the same ball, elec- *f 



tpified by fiealing-wux. I also satisfied myself by experi* 

 ment, that Xhe acid is indifferently attracted by a positively 

 ©r a negatively electrified metallic surface. It iis itnpossible ^ 



♦o operate on oxigen and hidrogen in their uncombineti j 



state, and tt>us to determine the truth of Mr. Davy's state- 

 wicnt, as it relatf%t» ihese substances, 'i his circumstance is, 

 however, the less to be regretted, a*, when analogies are 90 

 forcible, and so obviouf^, as in the present, instance, the 

 conclusions, which are drawn from them, arc received by tht 

 mind with a degree of certainty, little inferior to that, which 

 is derived from deiaonstratioii. 



Simple as these experiments may appear, they are de- jhese fticts 

 •idedly adverse to Mr. Davy's hypothesis, the essential and 



« Phil. Tf«w, 18©7, y. 3S i Journa), toI. XIX, p. 4i. ' , 



itdispcnsiblQ 



