220 
PHARMACEUTICAL  GLEANINGS. 
found  in  reduced  iron:  it  may  arise  from  two  sources  ;  1st,  from  the 
presence  of  sulphureted  hydrogen  in  the  hydrogen  used,  when 
the  sulphuret  present  is  that  of  iron ;  or  it  may  be  due  to  the 
deoxidation  of  sulphate  of  soda  in  the  oxide  of  iron,  when  sulphuret 
of  sodium  is  the  sulphuretted  body,  as  may  be  proved  by  washing  the 
iron.  It  is  almost  impossible,  on  a  manufacturing  scale,  to  wash 
all  the  sulphate  of  soda  from  the  hydrated  carbonate  of  iron  in 
the  process  of  making  the  sub-carbonate,  hence  it  is  necessary  to 
thoroughly  wash  the  dried  sub-carbonate  after  it  is  pulverized, 
till  the  washings  are  free  from  sulphate.  The  success  of  this 
operation  is  known  by  testing  the  reduced  iron  with  dilute  sul- 
phuric acid,  when,  if  any  sulphuret  is  present,  the  odor  of  hydro- 
sulphuric  acid  is  perceptible. 
In  my  experience  in  operating  with  a  wrought-iron  tube  forty 
inches  long  and  four  inches  diameter,  the  charge  of  oxide  is  six 
to  eight  pounds,  and  the  hydrogen  is  furnished  by  the  solution  of 
twelve  pounds  of  zinc  in  dilute  S03.  The  current  is  kept  up 
rapidly  for  eight  hours,  during  which  time  the  tube  is  kept  at  as 
near  a  dull  red  heat  as  possible  ;  and  after  the  removal  of  the  fire 
and  the  cooling  of  the  walls  of  the  furnace  with  water,  the  evolu- 
tion of  gas  is  moderated  to  a  slow  bubbling  at  the  exit  end, 
until  the  tube  is  perfectly  cold.  The  yield  of  reduced  iron  on 
the  average,  is  between  two  and  four  pounds  to  an  operation. 
The  black  pulverulent  oxide  in  the  other  end  of  the  tube  is  used 
for  part  of  the  next  charge.  The  most  difficult  point  in  the  pro- 
cess is  the  regulation  of  the  heat ;  the  next,  the  management  of  the 
gas,  which  should  be  carefully  purified  by  passing  it  twice 
through  a  solution  of  subacetate  of  lead. 
PHAKMACEUTICAL  GLEANINGS. 
The  following  formula  has  been  received  from  Mr.  Charles  T. 
Bonsall  of  Trenton,  New  Jersey. 
Solutio  Doveri.  (Liquor  Morphise  Compositum.) 
Take  of  Acetate  of  Morphia,       one  drachm. 
Diluted  acetic  acid, 
Dissolve,  and  add 
Diluted  alcohol, 
Wine  of  ipecac. 
one  fluidounce. 
seven  fluidounces. 
two  fluidounces. 
