Remarks on combustion. \g 



Combuftion for which we are indebted to that philofopher. 

 Some miftakes into which he fell were afterwards eorrecled by 

 Lavoifier *. 



From thefe fa£ts it is obvious, that the produces of combuf- When produth 

 tion may be formed without combuftion; but in thefe cafes a w j t h ut combuf- 

 new combufiible is always evolved. The procefs is merely an tion, a new com- 

 interchange of combuftibility ; for the combuftible is convert- ^ftibleia evolr- 

 ed into a product only by means of a product. Both the oxi- 

 gen and the bafe of the product having undergone combuflion, 

 have loft fomething which is eflential to combuflion. The 

 procefs is merely a double decomposition. The product yields 

 its oxigen to the combuftible, while at the fame time the com- 

 buftible gives out fomething to the bafe of the product ; the 

 combuftibility of that bafe then is reftored by the lofs of its ox- 

 igen, and by the reftoration of fomething which it receives 

 from the other combuftible thus converted into a product. 



There is indeed another method of forming the produces of Complicated cafe 



combuftion without a&ual combuftion in certain cafes; but ° f produces 



. ii- formed by nitric 



the phenomena are much more complicated. 1 his method is K \i > & c , 



to expofe them to the aclion of fome of the fupporters diffolved 

 in water ; efpecially nitric acid. Thus moft of the metallic 

 oxides may be formed without combuftion by the action of that 

 acid on the metals. But in that cafe a new fupporter is always 

 evolved, namely, nitrous gas ; ammonia, a new combuftible, 

 is ufually alfo formed ; and not unfrequently the produdt is 

 converted into a partial fupporter. 



7 . No fupporter can be produced by combuftion, or by any Oxigen may 

 equivalent procefs. Now as all the fupporters, except oxieen « oml)in f w "hout 

 ra c u- j u u r si c 11 lofing the mgre- 



gas, conn ft of oxigen combined with a bale, it follows as a dient which oc- 



confequence, that oxigen may combine with a bafe without c . afions combuf- 

 lofing that ingredient, whatever it is, which gives occafion to 

 combuftion. The a€i of combination of oxigen with a bafe, 

 therefore, is by no means the fame with combuftion. If we 



* When fulphate of iron Is dropt into a folution of muriate of 

 gold, nitrate of filver, or nitrate of mercury, the gold, filver, and 

 mercury are precipitated in the metallic ftate. This is an additional 

 reafon for fufpectfog that thefe three metals are not combuftible. 

 Every perfon, however, muft have obferved, that the metals in quef- 

 tion have not the metallic luftre when firft precipitated, and that 

 they acquire it flowly when allowed to remain expofed to the light, 



C 2 take 



