NEW  APPARATUS  FOR  RECTIFYING  SPIRITS. 
9 
is  continued  on  back  to  a  "charging  back"  for  supplying  fresh 
spirit  slowly  to  the  still,  in  the  manner  to  be  mentioned  in 
describing  the  working  of  the  apparatus. 
The  shelves  of  the  purifiers  may  be  supplied  with  quick  or 
slaked  lime,  with  chloride  of  calcium,  or,  indeed,  with  any  de- 
sired purifying  material,  whereby  alcohol,  or  any  other  vapor, 
may  be  purified  or  dehydrated  at  pleasure.  A  connection  with 
other  stills,  as  for  chloroform,  ether,  &c,  at  the  point  g,  adapts 
this  purifying  and  condensing  apparatus  to  use  for  these  vapors 
as  well. 
To  prepare  the  apparatus  for  use,  the  disks  are  placed  in  the 
column  from  below  upward,  and  the  interspaces  filled  with  well 
washed  pebble  stones  or  charcoal.  The  pebbles  or  charcoal 
should  be  separated  from  the  finer  and  coarser  particles  by  two 
sieves  or  riddles,  one  of  eight  and  the  other  of  four  meshes  to 
the  linear  inch.  When  pebbles  alone  are  used,  about  320  lbs. 
will  be  required.  The  three  sections  of  the  column  are  then  put 
together  and  secured  by  the  bolts  and  nuts,  and  the  column  then 
connected  to  the  goose.  The  automatic  water  valve  is  prepared 
by  filling  the  large  tube,  to  within  four  inches  of  the  top,  with 
mercury,  say  28  lbs.  Water  is  then  poured  in  till  the  whole  of 
the  tube  is  filled.  The  piston  is  prepared  by  cutting  out  and 
perforating  little  disks  of  sole  leather,  which  has  been  previ- 
ously hammered  well,  and  soaked  in  melted  tallow.  The  disks 
are  strung  upon  the  portion  of  the  piston  rod  adjusted  to  receive 
them,  and  then  firmly  compressed  into  place  by  screwing  the 
button-like  end  of  the  piston  upon  them.  The  piston  and  rod 
is  then  put  into  a  lathe,  and  the  packing  carefully  turned  to  the 
proper  size  to  fit  the  tube  closely.  It  is  then  well  greased  with 
tallow  and  put  in  place,  the  water  being  allowed  to  overflow 
through  the  upper  end  as  it  goes  down.  The  little  soft  iron  plug 
is  then  screwed  in  tightly,  and  the  milled  head  cover  put  on. 
The  goose  tub  being  filled  with  water,  the  water  is  heated  by 
passing  steam  into  it  till  it  acquires  a  temperature  of  about  174°. 
During  this  heating  up,  the  milled  head  cover  is  screwed  down 
upon  the  piston  rod  as  that  is  forced  up  by  the  expansion  of 
the  mercury,  till  the  desired  point  is  reached.  Then  the  end  is 
allowed  to  act  upon  the  lever  so  as  to  admit  cold  water. 
If  the  goose  tub  be  large  enough  and  deep  enough  in  its  pro- 
