14 HIS TORT of the SOCIETK 



fore, that more heat is loft by communication with the atmos- 

 phere than is acquired from the decompofition of the vital air. 



Now, let the experiment be fo far varied, that the incandef- 

 cent coal, inftead of being fufpended fingly in the atmofphere, 

 is furrounded with other burning coals, that are likewife fufpend- 

 ed, and at fuch a diftance from it as to leave room for the free 

 paffage of a current of air : We know, with certainty, that the 

 central coal will now continue to burn as long as thofe that fur- 

 round it are incandefcent, or emit a certain degree of light. But 

 the circumftances of the coal, in this experiment, are in nothing 

 more favourable to the receiving of heat from the decompofi- 

 tion of the vital air than they were in the former ; for if it be 

 faid, that the air afcends through the greater mafs of burning 

 matter, with more rapidity than before, and fo depofits more of 

 the calorique^ it muft be remembered, that it alfo abftradls more 

 heat from the coals, juft in the fame proportion, or in propor- 

 tion to its rapidity. If then the antiphlogiftic theory be true, the 

 heat acquired by the coal, in the one of thefe experiments, 

 Ihould be to the heat abflradled from it, in the fame ratio that 

 the heat, acquired in the other experiment, is to the heat abftracSl- 

 ed. But this does not hold ; for the heat acquired, in the firft 

 experiment, is lefs than the heat abftrafted, and in the fecond it 

 is not lefs, but is either equal, or greater. Therefore the anti- 

 phlogiftic theory is not true ; that is to fay, the theory which 

 derives the fupply of heat, in burning bodies, entirely from the 

 calorique of the vital air. 



We muft therefore admit another caufe, before we can fully 

 explain combuftion ; and this can be no other than the extrica- 

 tion of the phlogiftic matter of the body which is oxygenated, 

 the converiion of that matter into light, and then the produc- 

 tion of heat. 



In the phenomena of inflammation, Dr Hutton thinks that 

 the proofs of his theory of fire are no lefs conclufive than in 



thofe 



