new inflammable Air or Gafs , See. 381 
They had contrived a kind of a piftol for the purpofe, 
confifting of a ftrong cylindrical glafs tube with a pifton 
adapted to it. To the end of this tube was fixed a brafs 
barrel, like that of a common piftol : into this barrel a 
brafs bullet was put loofe, fo that the barrel was placed a 
little above the level, to prevent the bullet rolling out. 
The barrel was directed to a board of oak at eight or ten 
feet diftance. A proper quantity of common and inflam- 
mable air (produced in the manner above mentioned) 
being drawn into the glafs tube by means of the pifton, it 
was fired by directing an eleeftrical explofion through it. 
The explofion was very loud : the ball hit the board with 
fuch a force that it made a ftrong impreffion in it, and 
recoiled with a confiderable force, fo as to hit the wall 
behind us, and to put us in fome danger of being hurt 
by its rebounding force. 
The fame gentlemen told me, that this inflammable 
air had in fome refpetfts the advantage over the inflam- 
mable airs extracted from metals by the vitriolic or ma- 
rine acid, and that extracted from mud or mar flies; be- 
caufe this air being heavier than either of thefe airs, and 
even than common air, is not fo eafily loft out of an open 
veflel; and, that when it efcapes into the open air, it 
agreably perfumes the room with the fmell of fpiritus vi- 
trioli dulcis or aether; whereas the other inflammable airs, 
Vol. LXIX. E e e which 
