16 
ON  SOME    PHARMACEUTICAL  APPARATUS. 
comer  of  the  box  nearly  to  a  lower  diaphragm.  Between  this 
diaphragm  and  the  upper  one  the  space  is  separated  into  two 
equal  parts  by  a  series  of  transverse,  partial  partitions  or  plates, 
meeting  alternately  at  acute  angles  within  an  inch  of  the  oppo- 
site sides  of  the  box,  so  as  to  separate  the  water  for  condensing, 
which  passes  down  through  the  tube  and  gradually  fills  one  side, 
from  the  condensing  surface  and  space  for  the  vapor  which  en- 
ters at  a  conical  neck  c  just  below  the  upper  diaphragm.  The 
condensed  liquid  escapes  below  the  lower  diaphragm  at  the  side 
opposite  from  the  neck.  As  the  number  of  zigzag  plates  may 
be  increased,  the  amount  of  condensing  surface  may  be 
greatly  increased,  and  to  render  the  action  of  the  apparatus 
yet  more  efficient,  a  series  of  plates  are  soldered  to  the  side  pene- 
trated by  the  neck  so  as  to  extend  into  the  condensing  spaces, 
but  not  to  reach  the  partitions,  and  thus  compel  the  vapor  to 
take  a  zigzag  course  from  «  to  6  as  indicated  by  the  arrows,  in 
which  it  is  brought  into  contact  with  every  part  of  the  conden- 
sing surface.  As  the  cold  water  reaches  the  lower  surfaces  first, 
and  the  water  in  contact  with  the  upper  surfaces  gets  heated 
most,  it  follows  that  in  its  descent  the  vapor  will  meet  with  sur- 
faces increasingly  cold  until  they  are  efi'ecti.vely  reduced  to  the 
liquid  state  and  run  out  at  the  exit  d.  The  hot  water  escapes 
at  and  by  admitting  a  strong  current  of  cold  water  at  /  the 
amount  of  condensing  power  is  really  surprising. 
This  apparatus  is  not  unsightly,  occupies  but  a  small  space, 
and  may  be  lacquered  or  painted,  which  to  some  extent  will  pro- 
mote radiation  of  heat  from  outer  surfaces.  The  thin  conduct- 
ing material  of  which  it  is  constructed  admits  of  rapid  trans- 
mission of  heat  from  surface  to  surface.  Its  essential  merit  is 
its  condensing  power,  which  I  will  illustrate  as  follows  : 
If  this  condenser  be  24  inches  high,  and  12  by  13  in  diameters, 
with  twenty  four  12  inch  partitions,  (occupying  in  all  slightly 
more  than  two  cubic  feetj,  it  will  give  a  condensing  surface  of 
28  square  feet ;  or  4032  square  inches.  Now  compare  this  with 
the  ordinary  worm  condenser  of  one  inch  diameter,  and  72  feet 
long,  6  feet  coil  and  4  inches  fall ;  filling  a  space  3  by  5  feet  will 
give  but  2592  square  inches.  It  is  therefore  apparent  that  this 
apparatus,  occupying  slightly  more  than  two  cubic  feet,  is  capa- 
ble of  doing  the  work  of  a  worm  112  feet  long.    In  conclusion 
