14 
ON  A  STILL  FOR  APOTHECARIES. 
boiler,  and  forms  a  tight  joint  by  means  of  twine  or  gum- 
packing,  when  held  together  with  clamps.  Rising  from  this  is  a 
cylinder  of  tinned  iron,  b,  three  inches  high,  which  is  surmount- 
ed by  the  conical  condensing  surface,  c ;  united  by  means  of  a 
horizontal  ring  with  the  cylinder  before  mentioned.  On  the  out- 
side of  the  cone,  and  rising  from  its  base,  is  another  cylinder,  d, 
which  forms  the  receptacle  for  the  refrigerating  water.  Passing 
out  from  the  conical  condenser  is  a  tubular  neck,  e,  ten  inches 
long,  surrounded  for  three-fifths  of  its  length  with  a  jacket,/, 
which  opens  into  the  receptacle  for  water.  The  neck  is  attached 
to  the  head  so  that  all  the  liquid  that  condenses  on  the  inside  of 
the  cone  and  is  caught  in  the  gutter,  g,  at  once  runs  into  the 
neck,  and  is  thereby  conveyed  to  the  receptacle  or  receiver. 
Attached  to  the  inside  of  the  upper  cylinder,  immediately  above 
the  neck,  is  a  funnel  tube,  h,  which  bends  below  and  projects  into 
the  jacket,  above  the  neck.  On  the  side  opposite,  near  the  top, 
the  cylinder  is  penetrated  by  the  tube  i,  which  is  intended  to 
carry  off  the  heated  water.  The  apex  of  the  cone  is  surmount- 
ed by  a  short  tubulure  of  tin  an  inch  and  a  half  in  diameter, 
which  is  ordinarily  closed  by  a  tin  cap  slipping  over  it,  and  which 
may  be  closed  more  effectually  by  a  good  cork.  In  1848,  in  the 
American  edition  of  Mohr  and  Redwood's  Pharmacy,  the  writer 
described  under  the  name  of  "  Pharmaceutical  Still,"  an  appa- 
ratus analogous  to  the  above,  which,  however,  differed  in  two 
important  particulars :  1st,  in  having  a  water  joint  as  at  Jc,  fig.  2, 
instead  of  the  iron  flanges  ;  2d,  in  not  having  the  jacket  around 
the  neck,  which  is  really  the  greatest  improvement  in  the 
present  still.  The  chief  objections  to  the  water  joint  are,  first,  that 
it  will  not  admit  of  any  elasticity  in  the  internal  atmosphere  of 
the  still  without  forcing  out  or  sucking  in  the  water  in  the  joint; 
2d,  the  contents  of  the  boiler  cannot  be  removed  until  the  rim  is 
emptied  by  a  syphon,  and  then  in  pouring  out  the  contents  it 
gets  into  the  rim  ;  and  3d,  when  the  fluid  rises  by  rapid  ebulli- 
tion it  gets  into  the  joint,  and  is  diluted  or  spoiled  as  the  case 
may  be. 
It  now  remains  to  speak  of  the  manner  of  using  this  alembic, 
and  of  making   the  joint  tight.    After  charging  the  boiler 
