( 28 o ) 
CHAP. VI, 
« • 
A Specimen of an Attempt to analyze the Air, hy a 
great Variety of Chymio-Statical Experiments, which 
jhew, in how great a proportion Air is wrought 
into the Compofition of Animai Vegetable, and Mineral 
Sulflances j and withal how readily it refumes its 
former elaflkk State, when in the Diffolution of thofe 
Sulflances it is dijtngaged from them. 
T he excellent^ i^r. Boyle, among his many Dif- 
coveries, found, that Air was producible from 
Vegetables, by putting Grapes, Plums, Goofe-b'erries, 
Cherries, Peafe, and feveral other forts of Grain 
into exhaulled and unexhaufted Receivers, where 
they continued feveral Days, emitting great Quan- 
tities of Air. But Mr. Boyle did not ffiew the way 
to know exadly how much Air a certain Quantity 
of Vegetable Subftance will produce. 
The incomparable Sir Ifaac ^l^ewton {Query 31, of 
his Opticks') obferves, that “ true permanent Air 
“ arifes by Fermentation or Heat, from tliofe Bo- 
“ dies which the Chymifts call fixed, whofe Par- 
“ tides adhere by a ftrong Attraction, and are not 
“ therefore feparated and rarified without Fermentati- 
“ on. Thofe Particles receding from one another 
“ with the greateft repulfive force, and being moft 
difficultly brought together, which upon Contad: 
were mofl: ftrongly united. Andi (Query lof) Denfe 
“ Bodies by Fermentation ratify into feveral forts of 
“ Air, and this Air by Fermentation, and fometimes 
without it, returns into denfe Bodies. 
Mr. 
