C 2 3+ ] 



the conjectures of Dr. Franklin, made many years* 

 ago, and expreffed in the following extract from th'e 

 laft edition of his Letters, p. 346. 



6C I have been inclined to think that the fluid fire^ 

 {t as well as the fluid air, is attracted by plants in 

 " their growth, and becomes eonfolidated with the 

 « other materials of which they are formed, and, 

 " makes a great part of their fubftance j that, when 

 " they come to be digeited, and to fuffer in the: 

 " veifels a kind of fermentation, part of the fire, as 

 Si well as part of the air, recovers its fluid. active ftate 

 " again, and diffufes itfelf in the body, digefting and 

 « feparating it ; that the fire fo reproduced, by di- 

 " geftion and feparation, continually leaving the 

 " body, its place is fupplied by frefh quantities,, 

 " arifing from the continual feparation j that what- 

 c Jj ever quickens the motion of the fluids in an ani- 

 " mal quickens the feparation, and re-produces 

 t( more of the fire, as exercife ; that all the fire 

 tl emitted by wood, and other combuflibles, when 

 *< burning, exifled in them before, in a folid ftate, 

 " being only difcovered when feparating j that fome 

 " foflils, as fulphur, fea-coal, &c. contain a great 

 ct deal of fofid fire j and that, in ihiort, what efcapes 

 • c and is diflipated in the burning of bodies, befides 

 " water and earth, is generally the air, and fire 9 , 

 ** that before made parts of the folid." 



Of Air procured by means of spirit of salt*. 



Being very much ftruck with the refult of an ex- 

 periment of the Hon, Mr. Cavendifh, related PhiL 



Tranf, 



