172 CHEMICAL THEORY, 



.Dissertation on Before going farther, it raay be necessary to give some e?:- 

 effects of beat ^"""P'^s of the changes which galvanic influence proluces on 

 jipht, nndcom- substances, the nature of which, with respect to combustion, 

 "" ' * are A'eiy different. These substances may be arranged under 



fonr heads, supiorters of combustion, prcducts, inflammcible 

 substances, and detonating or deflagrating substances. One ex- 

 ample,with regard to a supporter of combustion,! have given in 

 treating of the conversion of atmosj heric air into nitiic acid. 

 It now remains therefore to make some remarks on muiiatic 

 acid. I do not know whether the same ex-^eriraent has been 

 riiade on this substance as on atmospheric air, but I amjn- 

 duced to think that a similar chinge would be observed, 

 scilicd, that on passing the electric fluid through it, light 

 would be absorbed, and heat evolved, th acid thereby becvira- 

 ing a supporter, or what is commonly called oxigenated mu- 

 riatic acid. I leave this to future experimenters to determine. 

 It appears to me, tliat oxirauriaiic acid is al ' ays obtained by 

 ' a process analogous %') that of passing electricity through 

 .muriatic acid ; a quantity pf a substance contairiing light in 

 a dense state is presented to it, and unites with it in precisely 

 the tame inanner as electrical light would. Black oxide of 

 mangau'-se, a supporter of combustion, a combination of 

 light, oxigen, and the base of an inflammable substance or a 

 metal, is presented tQ the muriatic acid, consisting of the 

 La,ses ofoxigcn and hydrogen gases, and which, at the same 

 time, is capable of absorbing and retaining ihe matter of 

 light, which it, in effect, receives from the b'^ck oxide, and 

 thereby becomes a supporter. In tliis instance wo. manifestly 

 have a translation of that substance, on which combustibility 

 depends, passing from the oxide to the muriatic acid, so that 

 what was before an iticonibustible becomes a supporter, and 

 that which was formerly a supporter becomes an incombusti- 

 ble. What name can we give to this chemical action ? is it 

 se.mi-combustion ? the heat only escapes! In all real cases of 

 combustion light accompanies it, in this it is retained. 



The most common supporter of combustion is oxigen gas, a 

 combination ofoxigcn and light: other supporters are ternary 

 compounds ; oxigen, aijotc, and light, in the nitric acid, and 

 oxigen, the base of an inflammable, and light, in the oximri- 

 riatic acid j the metallic supporters arc combinations of hcjht, 



o\ii:<;ii. 



