Woulfe's or NootK's Apparatus. 411 



neck of the exterior bell glass is introduced into the tubulure 

 of the receiver above, and receives the neck of the interior 

 bell glass. Into this is inserted a trumpet-shaped tube. The 

 two interior jars are furnished with feet F,/. In order to put 

 this apparatus into operation, remove (without taking them 

 apart) the bell glasses, receiver, and tube from the jars. Pour 

 into the latter the fluid, to be impregnated, till it reaches the 

 height marked by the dots. The funnel mouth, m, of the re- 

 ceiver being provided with a suitable cork soaked in wax, fas- 

 ten into it firmly the beak of the retort, containing the gene- 

 rating materials. The bell glasses are then to be replaced in 

 the jars, and arranged as in the figure. It must be self-evident 

 that the gas proceeding from the retort, (if the juncture at m 

 be air tight) must press on the fluid in the innermost jar, 

 through the trumpet-shaped tube. If not imbibed with ade- 

 quate speed, it must soon press on the fluid at a, causing it to 

 subside to the narrow part of the foot/, and thus to expose a 

 much larger surface. If the absorption be still inadequate, a 

 further subsidence must ensue, and the gas escaping round the 

 brim of the interior bell glass will act on the fluid at h, and en- 

 large its surface by depressing it to the narrow part of the 

 foot F. Should the increased pressure and more extended 

 contact thus obtained, be still incompetent to effect a complete 

 absorption, the excess of the gas may escape round the brim 

 of the external bell glass into the atmosphere. 



But so effectual is this process in promoting impregnation, 

 that I have obtained strong muriatic acid in the central jar, 

 without producing any sensible acidity in the outside one. 

 Absorption into the retort or receiver, is prevented by not al- 

 lowing as much fluid to be above the mouth of the trumpet- 

 shaped tube, as would be competent to fill the cavity between 

 it, and the termination of the open neck of the exterior bell 

 glass at t. As this neck rises about 2 or 3 inches into the re- 

 ceiver, it prevents any foul matter which may condense or boil 

 over, from getting into the jars. If practicable, it would be 

 better that the bell glasses, and tube, and receiver, should be 

 united together while hot, at the glass-bouse. If all could not 

 be joined in this way, it would still be advantageous to unite 



