It will then appear by the Experiments and Calculation , 
made by our Noble Author, that, according to the leaft Efti- 
xnate of any recited in them, the Extenfion of the lame Qjian- 
tity of Airj is as i. to 2744, or thereabouts : And ifjinftead of 
the moderateft, there be taken the greateft Expanfion of the 
Air^ being as about 1500c to \^hen the HPfcomprefl Air was 
highly rarify'dj that number being multiplyed by 40 , becaufe 
of the great Compreffion of the Air, efft fted by Cold(as ap- 
pears in the Third of thefe Traftsj) wil l amov nt to 520000, 
for the number of times, by which the Air at Oii time exceeds 
the fame portion of Air at another time : Which is an Eiq>an- 
fion ib greatjthatit willeafily keep the Reader from thinking 
the Title of this Difcourfe , where the fiarefadionof the Air 
h c2l\Y A Admit able ^'iVLmodtik. 
It will alfo appear by thefe Trafts , that the Air may by the 
Intervention of Art and Inftrumeors be much more expanded, 
than it has yen been found to be by the b,ire application of 
External Heat^ though it were that of an Intenle Fire it felf<. 
The Natural Philofopher will doubtlefi^ upon the reading 
of this ftrange Expanfion of the Air, be excited to coofider, 
when he lhall look on one of pur Author's well exhaufted Re- 
ceiverSjHow fmall a proportion the Common Aerea! particles^ 
which are very Sparingly difpers'd there ^ bear to the whole 
Cavity of the Veflelj whichj before it was exhaufted, was 
thought to be repleoifh't with Air alone. Certainly both the 
Cdrtefims and Epicureanf will find themfelves highly .con* 
cern'd iei this matter. The /i?r^;er will endeavor thereby to ^ 
eftablifh the neceffity of their Materia fubtilis, to maintain the 
Tlenitudeoi the World, and the Circle they attribute to Mo»- 
ving Bodies. The latter will thinkj they have caufe here to 
triumph, as believing to have met with a more illuftrious In- 
ftancCj than ever, of their Vacuum . CoacervatHm.:Withm the 
World % fince here i^an impenetrable Veffelj out of which 'tis 
mapifeftj that an almoft incredible proportion of Aerial fub- 
ftance hath been made to ifliie 5 whereas 'tis no ways manifeft • 
to any of our fetif^Sjthat any other Body hath got in to fucceed ■ 
in its room^ 
li ELEMENTAL'. 
