APPARATUS  FOE  THE  USE  OF  GAS  IN  PHARMACY. 
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vessel,  in  ten  minutes  burning,  at  the  rate  of  four  cubie  feet  per 
hour. 
For  the  purposes  of  the  pharmaceutist,  it  is  a  desideratum  to 
be  able  to  get  a  high  or  low  heat  at  pleasure,  and  except  in  a 
very  few  instances  it  is  not  desirable  to  concentrate  the  flame 
upon  a  limited  surface,  so  that  many  of  the  appliances  which 
produce  the  most  complete  and  intense  combustion  of  the  gas 
are  not  well  suited  to  his  wants. 
In  studying  this  subject  with  reference  to  my  own  wants,  and 
endeavoring  to  meet  with  a  perfect  form  of  apparatus  for  evapo- 
ration, decoction,  and  all  the  other  applications  of  heat  in  the 
shop,  I  met  with  a  furnace  of  English  pattern  upon  which  I 
think  I  have  made  an  improvement,  fitting  it  admirably  to  the 
ordinary  uses  of  the  pharmaceutical  shop  and  laboratory.  This 
is  here  figured. 
Fig.  1  represents  a  small  cast  iron  furnace  of  an  English 
pattern,  originally  obtained  from  Smith  &  Phillips,  London,  into 
which  passes,  through  a  lateral  opening,  a  burner  of  two  rings, 
fig.  2,  perforated  at  suitable  distances  with  small  holes.  For  all 
purposes  requiring  a  moderate  and  diffused  heat,  as  in  the  eva- 
poration of  the  extracts  and  fluid  extracts,  and  the  distillation 
of  the  distilled  spirits,  this  answers  an  admirable  purpose.  The 
scolloped  rim  allows  the  free  passage  of  a  draft  of  air  from  the 
flame  when  the  furnace  is  covered  by  a  receiving  vessel,  while 
the  distance  of  the  receiving  vessel  from  the  flame  prevents  the 
deposit  of  soot  upon  it,  unless  when  the  flame  is  near  its  highest, 
which  it  need  not  be  for  the  purposes  named.  The  star  is  a 
casting  for  laying  over  the  throat  of  the  furnace,  adapted  to 
holding  small  flasks  or  capsules  over  the  jets  of  flame. 
Fig.  3  and  4  represent  two  rings  of  cast  iron,  the  lower  of 
which  fits  accurately  in  the  throat  of  the  furnace,  and  is  covered 
with  wire  gauze ;  the  upper  is  a  flange  with  projecting  arms  for 
