r ) 
• ment, thatwa-s.made ufe of to fafteii the'BraYs Cap to it, 
fuffer’d fuch a Softnefs, as render’d it uncapable to refift 
'* the Spring of the Injeded Air. I obferv’d, that altho’ 
all the Air- as was capable of fpring was fled, yet the 
Mercury in the Gage remain’d about three quarters of 
an Inchin height, above the Surface of that in which its 
open end was immers’d ; which was about a 6th part lefs 
fpace,thaivwhat the lame Air poflefl: before die Injeftion, 
and ftill remains fo, notwithlfanding it is conftantly ex- 
pos’d to the open Air. Which manifellly fhews, that the 
Springs, or conflituent Parts of the Air, do not in time 
totally reflore themfelves after {landing fo long bent. 
And had not the Accident of Heat happen’d, but it had 
continu’d in that State, as at firfl Injefted, for a Year or 
two, (as 1 hop’d for) I doubt not, but the Springs of it 
would have been render’d much more incapable of their 
Reiloration. From hence it is eafie to conclude, that if 
nine or ten Atmofpheres of Air were condens’d in the 
fpace of one, and to remain in that State for a Year or 
two ; that when the Veflcl, that contains them, fliall be- 
. come expos’d open to the Air, that then Bodies, fuch as 
very thin Glafs Bubbles, (fuppofing them not to be a- 
bove five or fix times fpecifically heavier than their like 
Bulk of common Air) would float .on fuch a Medium, 
which would be very furprifing, to fee a Body fupport- 
ed by an Invifible Agent. But I am not fure of this, for 
I cannot tell but it may be a means to render Air vifi- 
ble ; From whence fome Difeoveries may be made, 
which otherwife it may be impoflible to know. But let 
it happen how it will (for Nature will have her own 
ways) I doubt not but feveral ufeful Inferences may.be 
made from- fuch an Experiment. 
IV. An 
