2$t Analyfis of the Air. 
tion of the acid fulphureous particles of the 
fuel, and the elaftick ones which arife and 
enter the Fire, either from the fuel in which 
they abound, or from the circumambient 
air: For by Experiment 103, and many 
others, acid fulphureous particles aft vigo- 
roufly on air 5 and fince a&ion and re-a£tion 
are reciprocal, fo mufl: air on fulphur; and 
there is we fee, plenty of both, as well in 
mineral as vegetable fuel, as alfo in animal 
fubftances, for which reafon they will burn. 
But when the acid fulphur, which we fee 
a&s vigoroufly on air, is taken out of any 
fuel, the remaining Salty Water and Earth 
are not inflammable, but on the contrary 
quench and retard fire 5 and, as air cannot 
produce fire without fulphur, fo neither can 
fulphur burn without air: Thus Charcoal 
heated to an intenfe degree for many hours 
in a clofe veflel will not burn as in the open 
air, it will only be red hot all the time like a 
mafs of Gold without wafting: But no 
fooner is it expofed to the free air, but the 
fulphur, by the violent aftion and re-a&ion 
between that and the elaftick air, is foon fe- 
parated and carried off from the Salt and 
Earth, which are thereby reduced from a 
folid and hard to a foft impalpable calx. 
And 
