ON THE THEORY OF COMBUSTION* £07 



the very luminous manner in which he conveys information, 

 en every fubject that he treats. , The Paper under con fidera* 

 tion is particularly an inftance in point, and if we cannot go 

 the full length with the author, we mutt at leaft acknowledge, 

 that in the chief, his diftinctions are accurate, and his reafon- 

 ing juft. Nothing can be more evident than the difference 

 which in numberlefs inftances prevails, between the act of 

 oxigenation in bodies, and that of combuftion, inafmuch as 

 neither the phenomena attending them, nor the refults ari- 

 fing therefrom, are the fame. The French chemifts, how- 

 ever, feem to have been miffed, in their confining the term 

 combuffion to the act of oxigenation, by conlidering, that all 

 bodies during their combuffion combine with oxigen, without 

 at the fame time recollecting, that this latter effect may be 

 produced without any of the phenomena ufually attendant on 

 combuftion, and that though certainly all combuffion prefup- 

 pofes the combination of oxigen with a bafe, yet this combi- 

 nation may, and repeatedly is effected where no combuftion 

 can poflibly take place. 



That a diftinction therefore prevails between the two is ob- 

 vious, and the Doctor offers us a theory, which he confiders 

 as fufficient to explain the different phaenomena produced. — 

 This theory it is the purpofe of the following lines to fliew 

 however ingenious, aud apparently falisfactory it may appear 

 to be, is not wholly adequate to Ihe talk that is affigned to it. 

 It will be neceffary very fhortly to ftate here the outline of the Outline of the 

 theory under confideration. In all cales fays Dr. Thomfon *, J eo f. y *t T !? at 

 when heat and light are extricated during combuftion, it will combuftion is 

 be found, that the light is furniihed by the combuftible or ■fi»«ufl>ejl by the 

 burning body, and the heat by the decompofition of the oxi- and t h e 'h^ \* 

 gen, which forms a component part of the fupporter, and the oxi-en of 

 which is effential to the combuftion, and that the diftinction uppor 

 that prevails between the two proceffes of combuftion, and of 

 oxigenation, arifes from the difference of the phaenomena, 

 which accompany the action of iupporters and products upon 

 other combuftibles. " The iupporters convert thefe bodies but that produces 

 into products, and combuftion, -or the emiffion of heat and co " ver . c combuf " 



..«,/. tibles into pro- 



bght at the fame time take place ; whereas, the products con- duels by mere ox- 



vert combuftibles into products, without any fuch emiffion. k en f twn ™Mout 



copibuftiort, 



* Fhilof. Journal, New Series, II. 10 and 92. 



Now 



