[ 7 ] 
After trying feveral Methods, which did not fully 
fatisfy me, I fixed upon the Glafs, which is repre- 
fented in the annexed Figures, Tab. I. Fig. i. and 2. 
Its Difference from the common ones confifts in 
having, quite round the Edge of its Orifice, a circu- 
lar Groove or Chanel, Fig. 1. A A, an Inch deep 
for the fmaller Sizes, and two Inches for the larger. 
This circular Groove is intended to receive a Bor- 
der, SB, of the fame Figure on the Cover C : In 
the middle of the Concavity of this Cover is a dou- 
ble Hook, on which the Threads are to be fattened, 
which fufpend the Piece or Preparation that is to 
be pur into the Glafs. ' . 
In putting the Piece into the Glafs, which con- 
tains the preftrving Liquor, Care muft be taken to 
place it on the Hooks in the fame Pofition, which 
you intend it fhould keep in the Glafs: That done, 
you are to pour Oil, or Quickfilver, which is bet- 
ter, into the circular Groove AA y fo as to make it 
about half-full. Then you are to let down the 
Piece into the preferving Liquor ; and when it is 
intirely funk down, the Cover C ought to light upon 
the Glafs, and its circular Border BB , enter into the 
circular Groove A A, Where it falls into the Oil or 
Quickfilver, which rifes up and fills the whole Groove; 
by which means the Glafs is in fome meafure her- 
metically fealed, The Oil indeed permits fome fmall 
Evaporation ; the Quickfilver more completely an- 
fwers the End of this Invention, but it is more ex- 
penfive, 
As I had contrived this Glafs for my own private 
Ufe, I negle&ed making it public; till, happening 
to be prefent at the public Meeting of the Academy 
of 
