289

It was thought very Desirable that Querys should be made
concerning the Differing Grauitation and pressure of the
Atmosphere in seuerall parts of the earth that by the
Comparing those together the Theory might be thereby
compleated./
mr. Hally affirmed that he had made obseruation of the
height of the mercury in the Barometer at St. Helena
and that he had found the height thereof but 27 inches
at the top of the Hill, when it was 29 inches at the
Bottom neer the water side.
mr. Hooke Propounded mr. Edward Tison for a candidate
as being a person very curious in Anatomy and one tht
would be very vsefull to the Scoiety in producing obser
uations of that kind.

vpon Reading the Account of the Expts. shewn the Last Day
for explaining the Hypothesis of fire, and Particularly
that of the salt Peter. Sr. Ionas more was very Desirous
to know by wt. meanes he might certainly find wt quantity
of salt peter any Gunpowder he was to examine conteined
And he Receiued for Answer that he might Easily be resolued in
that Enquiry if he tooke a certaine quantity of the Powder
he Designed to Examine; and steeped it in soe much water as
would Dissolue all the peter conteined in the powder. . then
filtred the water through Cap paper and gently Euaporated
the solution in a ^ /broad/ glasse vessell, for by the Remaining salt
after euaporation he would easily know what quantity
of Peter each pound or Barrell of Gunpowder conteined

He added moreouer that there was Great Difference in the
Goodnesse of seuerall saltpeters. That Dutch Peter would
wast but 4 pounds in a hundred but that English Peter would
wast 18.
There being A Full number of the Society for Election, Sr
William Waller formerly proposed Candidate was Putt to the
Ballot & Elected Nomine Contradicente.

Ref: CELL/RS/HF_291  © Centre for Editing Lives and Letters