ON  SOME    PHARMACEUTICAL  APPARATUS. 
15 
paratus  to  facilitate  the  filtration  of  fixed  oils,  sjrups  and  viscid 
solutions  would  be  readily  acknowledged,  and  would  fill  a  desider- 
atum arising  from  the  necessity  for  such  an  arrangement,  has  led 
me  to  this  efi'ort  to  supply  it.  We  have  had  hitherto  no  arrange- 
ments or  apparatus  well  adapted  to  our  wants  in  this  respect,  and 
the  simiple  filter  bag  or  Hippocrates''  sleeve,  though  good  enough  for 
some  purposes,  is  as  primitive  as  the  name  might  suggest,  and 
has  been  mostly  the  only  means  employed  by  wholesale  dealers 
and  others,  some  of  whom  have  several  apartments  for  the  filter- 
ing of  castor  oil,  and  extensive  arrangements  for  heating  in  order 
to  render  more  fluid  the  oils  which  are  filtering  in  these  apartments. 
The  invention  which  I  have  endeavored  to  illustrate  embraces 
the  essential  ideas  of  filtration  upwards,  the  employment  of 
the  law  of  liquid  pressure,  and  the  application  of  heat  to  increase 
fluidity  of  substances  filtering,  the  importance  of  all  of  which 
I  think  is  apparent  and  requires  no  comment. 
Some  eight  years  since  Prof.  Procter  invented  an  apparatus, 
as  he  informs  me,  for  filtering  oils,  which  embraced  the  principle 
of  upward  filtration,  of  this  arrangement,  but  none  of  its  other 
advantages. 
The  entire  exclusion  of  dust,  which  the  exposed  oils  so 
readily  catch,  is  effected,  and  the  oxidation  of  them  from  pro- 
tracted and  tedious  filtering  by  the  ordinary  method,  are  all 
prevented  by  this  apparatus. 
The  Condenser  (or  <gack  in 
the  box,"  as  our  smith  calls  it) 
is  especially  applicable  to  the 
condensation  of  alcoholic  va- 
pors. It  consists  of  a  square 
tinned  iron  box  of  twice  the 
height  of  its  diameter  with  a 
canister  like  flanch  and  lid  at 
the  top.  A  few  inches  below 
the  top  is  a  diaphragm  of  tinned 
iron  soldered  in  diagonally  so 
as  to  be  lower  at  one  corner 
than  at  the  other  three.  At 
this  lowest  corner  a  vertical 
tube  is  ?oldered  in  the  dia- 
phragm which  descends  in  that 
