Woulfe’s or Nobth’s Apparatus. au 
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,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 fiuid to be impregnated, till it reaches the 
height marked by the dots. The fannel 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 asin 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, 
* 
i. 
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 f, 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 4, 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 effectually 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 ¢. 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-house. If all could not 
be‘joined in’ this way, it would be still advantageous to unite. 
