C 7»o ) 
too much Ihorteny, the litcle Teat or Segment of fpherc,latdy 
mcntion'd, began to be fomewhat flattened, and fabfided more 
and more as the Water was further taken off. 
I Becaufe the common Atmiffherical Air we breath is a Flu- 
id body abounding with groffer pa^rticles, and is by 
Exp. IX. divers Philofophers probably fuppofedto be much 
more denfe and heavy than thttMthereal fubftance, 
thatmakes the other pare of the Atmofphere; I thought fit to 
try for their fakes, whether or no the /»^^r/fewi Figure of Li- 
quors would be alcer'd by having the contiguous Air with- 
drawn from about them, and fo being left to be touch'd by the 
purer .either without it \ and accordingly having conveyed in- 
to one of our PneumAtical Receivers a couple of fuch Slender 
pipes as have been already defcribed , one of them furnifh'd 
with Common water, and the other with Quickfilver , we cau- 
Ted the Common air to be diligently pump'd out, without ob- 
fervingany fenfible change in the Concave Figure of the water: 
but as for the Quickfilver, I knew not what to conclude about 
it. For having repeated the Trial twice or thrice, the CMer*^ 
c»r/fometimes fecm'dmanifeftly tofwell to be more protube- 
rant upon the Exhauftion of the Receiver , than when it was 
put in, efpecially when its Figure was attentively view'd, and 
the External air, that was pumpt out but flowly, wasfuffered 
to reenter with all convenient celerity. But that which yet 
kept me doubtful was, that I obferved,that upon the diligent 
withdrawing of the Airs preffure on the Quickfilver , there 
difclofed themfelves in it fome little bubbles, which I fear'd 
we had not been able to free it altogether from , and which 
might be fufpefied to have fome intereft in the Phanomemn \ 
which though it was at that time hinder'd by fome occafions 
from profecuting further, yet I think it may be well worth 
the while, becaufe, if any fenfible change do certainly appear 
to be made in the Superficial figure of the Mercury^ it may 
teach us fomewhat relating to the Gonftitutioa of the^ther, 
which feems to make up far the greater part of the Univcrfe 
known to us: And I Ihould not in that cafe think it impofllble, 
that by expofing many and differing Liquors to its Conradi 
in vncHo BoylUm (as 'tis call'd) fome difcovery may be made 
of differing Subftances, whereof one may fufpeft the iEther it 
fclf not to be uncapable. Bat to leave fufpicions that pro- 
bably 
