C ass.] 



I is a funnel of glafs or tin, which is neceflary* 

 for transferring, air into veflels which have narrow 

 mouths. 



K is a glafs fyphon, which is very ufeful for 

 drawing air out of a vefiel 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 vefTel, which Dr. Hales very 

 often made ufe of; for, fince my firft difappoint- 

 ments, I have never thought the communication^ 

 between the external and internal air fufficiently 

 cut off, unlefs glafs, or a body of water, or, ill- 

 fome cafes, quickiilver,. have intervened between 

 them. 



L# is a piece of a gun barrel, clofed at one end, 

 having the flem of a tobacco-pipe luted to the 

 other. To the end of this pipe I fometimes fatten- 

 ed a flaccid bladder, in order to receive the air dif- 

 eharged 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 veflel full of water, and {landing with its mouth 

 inverted in another veffel of water, that the new 

 air might have a move perfect 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 inferred 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- 

 jecting beyond the flat flones C C for that pur- 

 pofe.. 

 ' • AN, 







