from each other , fince that they may ua-feparatcd Aide 
down by the fides of the Glafs ^ to which, it is well koown, 
and vifible to the eye, the Quickfilver is not at ^11 apt to 
ftick, but doth rather decline that contaft 5 in like maoner 
as we find Water not apt to Joyn with Oyle or Greafe 5 
though Water to Glafs, and Quickfilver to Gold, do very 
readily apply themfel ve$. So that there needs no fuch Force 
to di( joyn the Quickfilver from the Glafi, whatever there 
may be for dif- joyning its parts one from another* 
If therefore we {hould fuppofe the preffure oftbe Grofer 
Air downwards on AB (the furface of the ftagnant Qiiick- 
filver,) and confequently, by means thereof, upwards at 
fufficient only to bear up that in the Tube to the height of 1$ 
but the fuper.added weight or preffure of the P^rer Air 
to hold it up as high as D ( 75 inches or mox^, ) while it is 
full, and the Quickfilver well cleans'ds as if foloogk 
could not enter at D 5 but in cafe it be not fo cleanfed^cr be 
already funk to H ^ this $urer Air would enter at D ; and 
Uuuuu thruft 
