172 OBJECTIONS TO THE MODE-UN CHEMICAL THEORY. 



air, but the expansible power, which causes water to assume 



Metallic calces t» at peculiar aeriform state. The same reasoning holds good 



reduced by one w ith respect to the galvanic property of the negative end of 



Si^the other". tne P'' e > as m tne instance of metallic calces being reducible 



to their metallic state; and we account for this by saying, 



that the oxidated or positive state of the metal is destroyed 



by its being saturated with the hidrogenous or negative 



Bodies burnt p 0vver f the pile. Jn short, bodies are burnt by the power 



burnt by the or principle which comes from one end of the pile, and un- 



other. burnt by the power or principle which comes from the other 



end of the pile. 

 Metals render- Metals are combustible bodies, and in becoming oxides 

 busrible^by the tnev are burnt. Metals not easily burnt are rendered more 

 negative end combustible by being connected with the negative end of 

 epl the pile. Thus copper, which is easier converted into an ox- 



ide than silver, will in ordinary cases take the acid from a 

 solution of silver in nitrous acid, and the silver will be de- 

 and thus their posited in its metallic form ; but if silver be rendered more 

 chaneed combustible by being connected with the pile, it will then 



A supersede the copper in its attraction for the acid, and the 



copper will be deposited in its metallic form. The above 

 proves, that a real and distinct power is communicated to the 

 silver by the pile. 

 Neutral salts Mr. Davy has shown, that neutral salts are decomposed 

 "alvaTiism edby by HW P owers ot> the pile ; that the acids appear on the posi- 

 tive side, and the bases on the negative; and that, when 

 muriatic salts are decomposed, the oxigenated muriatic acid 

 Galvanic appa- appears on the positive side. The galvanic apparatus re- 

 ritus decom- so lves the matter of heat into its two- constituent principles, 

 teTof heat into which principles, being thereby freed from their affinity with 

 nstwopiinci- eac h other, are at liberty to enter into new combinations; 

 these combinations of the one, as with water in oxigen air, 

 in acids, metallic oxides, &c. ; and of the other in combusti- 

 Experiments ble bodies of all kinds, I shall attempt to illustrate by expe- 

 promued. riments, which I shall take the liberty of transmitting to you 

 in a future letter. 



I am, Sir, 



Yours, &c. 



G. S. GIBBES. 



III. 



