( iSp ) 
gut^ weighing two Ounces fifteen Penny-weight 
ten Grains, acquired not the leaft Augmentation 
thereto, by being fufpended for a very confiderable 
Time. ^ 
To thefe Experiments we added one upon the Hy- 
drqfiatkal Ballance^ in order to determine whether 
there was any extraordinary Difference as to the 
Denfity, or Specifick Gravity of common, and this 
vitiated Air, The Ballance we made ufe of was 
very large,* and accurately poiz’d, and the SoUd^ 
which was a Globe, was four Inches eight tenths in 
Diameter. This with its String weigh’d in the Air 
feven Ounces fix Penny-weight. And after we had 
immers’d it in the Damp^ it loft nothing of its Weight, , 
being then in jEquilihrio to fo great a Degree of 
Exadnefs, that half a Grain would over- ponderate- 
on either Side. 
• This Damp abated more and more by being expofed 
to the Air, till on July the xfth, Perfons were let 
down to the Bottom without any Inconvenience. 
The other Inftance is of a very fudden Subterra- 
neous Vapour, on May 9, 172-9, i^^ a Well in School*- 
houfe-Streety Bojlon, 
This Well had been opened for fome confiderable 
Time , and not only enlarged in its Diameter, but ' 
funk fourteen or fifteen Feet deeper.' Hereupon-: 
Mr. Renniej\ and a young Man whofe Name was 
Rujjeh undertook to lay the Stones, They had 
been employ’d all the Day, till about fix o Clock in 
the Afternoon, when Rennief perceived a very un- 
ufual Stench, of which, he firft upbraided his Part- 
ner as an Ad of Indecency, till by the extraordinary 
, Increafe. 
