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I is a funnel of glafs or tin, which is neceflary 
for transferring air into veffels which have narrow 
mouths. 
K is a glafs fyphon, which is very ufeful for 
drawing air out of a veffel which has its mouth 
immerfed in water, and thereby railing the water 
to whatever height may be moft convenient. I do 
not think it by any means fafe to depend upon a 
valve at the top of a veffel, which Dr. Hales very 
often made ufe of ; for, fince my find: disappoint- 
ments, I have never thought the communication 
between the external and internal air fufficiently 
cut off, unlefs glafs, or a body of water, or, in 
fome cafes, quickfilver, have intervened between 
them. 
L, is a piece of a gun barrel, clofed at one end, 
having the Idem of a tobacco-pipe luted to th« 
other. To the end of this pipe I fometimes faften- 
ed a flaccid bladder, in order to receive the air dif- 
charged from the fubftance contained in the bar- 
rel ; but, when the air was generated (lowly, I com- 
monly contrived to put this end of the pipe under 
a veffel full of water, and (landing with its mouth 
inverted in another veffel of water, that the new 
air might have a more perfeft feparation from the 
external air than a bladder could make. 
M is a fmall phial containing fome mixture that 
will generate air. This air paffes through a bent 
glafs tube inferted into the cork at one end, and 
going under the edge of the jar N at the other ; 
the jar being placed with part of its mouth pro- 
j^ffing beyond the flat flones C C for that pur- 
pofe* 
AN 
