AN  AUTOMATIC  PHARMACEUTICAL  STILL.  16T 
steam  in  the  water  boiler  will  be  more  than  necessary,  the  super- 
fluous steam  escapes  through  the  valve  g. 
In  case  the  bottle  Gr  should  become  empty,  an  alarm  pipe, 
attached  to  e,  will  give  the  alarm  as  soon  as  the  water  falls  below 
the  extremity  of  the  pipe  a. 
The  inner  boiler  B,  made  of  a  suitable  size,  can  be  fed,  if  de- 
sired, in  the  same  manner  as  the  outer  boiler.  On  the  top  of 
the  inner  boiler  fits  also  a  porcelain  evaporating  dish,  for  those 
cases  where  the  liquid  would  corrode  the  boiler.  The  conduct- 
ing pipe  D  is  connected  with  the  dome  C  and  the  condenser  E 
by  means  of  cast-iron  and  India-rubber  rings  and  screws,  so  as 
to  make  perfect  steam-tight  connections. 
Without  the  inner  boiler  B,  the  apparatus  will  be  sufficient  for 
making  aquce  distillatce,  and  a  perforated  diaphragm  put  near 
the  surface  of  the  water  will  make  the  apparatus  suitable  for 
distilling  medicated  waters  or  essential  oils  from  flowers  or  herbs. 
On  this  apparatus,  after  detaching  the  conducting  pipe  D,  the 
condenser  can  be  easily  cleaned  and  deprived  of  the  odor  of  dif- 
ferent substances,  so  that  the  objection  raised  against  the  con- 
densing worm  is  removed. 
Without  the  dome  C,  etc.,  the  inner  boiler  B  (screwed  tight 
to  the  outer  boiler  A)  will  be  suitable  for  boiling  syrups,  etc.* 
also  for  evaporating,  for  which  purpose  a  separate  dome  may  be 
substituted  to  carry  off  the  steam  to  a  flue.  In  this  case,  the 
dome  C  should  not  fit  tight,  but  be  slightly  raised,  so  as  to  leave 
a  space  not  quite  so  large  as  the  space  in  the  pipe  D,  so  as  to 
bring  on  a  draught  when  the  pipe  D  is  connected  with  a  chimney 
flue,  by  which  the  generated  steam  will  be  rapidly  carried  off, 
and  so  the  evaporation  greatly  favored. 
As  plainly  seen,  the  quantity  of  liquid  in  the  apparatus  is 
very  small  at  the  time,  and,  consequently,  very  little  heat  is 
required  to  bring  on  distillation,  yet  the  evaporated  liquid  is 
instantaneously  replaced,  and  so  a  continuous  distillation  kept 
up ;  consequently  the  saving  of  fuel  will  be  considerable,  and 
this  will  make  the  apparatus,  together  with  the  safety  from 
scorching,  the  most  suitable  one  for  stoves  in  drug  or  apothecary 
stores,  or  for  gas  furnaces. 
