3i6 
Production  of  Hydrogen. 
Am.  Jour.  Pharm. 
Juty,  19 17. 
uniformity  in  the  heating  by  introducing  air  to  the  ore  mass  at 
various  points  during  the  reducing  process.  It  is  evident  that  under 
this  system  the  reducing  capacity  of  the  gases  was  seriously  affected, 
so  that  the  yield  of  hydrogen  was  altogether  too  low. 
Lewes 's  English  patents  4134  and  20,752,  dated  1890  and  1891, 
once  more  describe  the  iron  contact  method  in  detail.  He  proposed 
to  lay  a  retort  with  iron  contact  mass  directly  through  a  water  gas 
generator,  which  was  technically  hopeless  owing  to  the  consequent 
overheating.  He  proposed  for  the  first  time  to  employ  porous 
briquettes  made  of  iron  oxide  and  clay  or  asbestos  and  then  pressed 
and  burned.  He  employed  water  gas  for  reducing,  justly  pointing 
out  that  the  use  of  such  gas  rich  in  hydrogen  greatly  accelerated  the 
process  of  reduction. 
Hills  describes  in  his  English  patent  10,356,  dated  1903,  the  pro- 
duction of  hydrogen  by  the  iron  contact  method,  which  he  proposes 
to  carry  out  in  iron  retorts.  Unimportant  improvements  in  the  ap- 
paratus employed  in  the  already  well  known  process  were  patented 
by  him.   He  used  water  gas  for  the  reducing  process. 
Elworthy,  in  German  patent  64,721,  dated  1905,  discusses  the 
contact  method  exhaustively.  He  notes  as  the  chief  defects  the 
tendency  of  the  mass  to  melt  and  the  choking  of  the  retorts.  He 
proposes  to  overcome  this  difficulty  by  using  furnaces  in  which  the 
spongy  iron  is  contained  in  specially  constructed  fireclay  holders. 
The  use  of  iron  in  lumps  of  varying  size  is  taken  for  granted.  By 
"  iron  "  he  always  means  spongy  iron  produced  by  reduction  from 
iron  oxide  or  iron  ore,  as,  he  explicitly  states  in  his  English  patent 
12,461,  dated  1902,  he  employs  water  gas  for  the  reducing  process. 
Lane  repeatedly  constructed  installations  in  Russia,  France  and 
England  about  12  to  14  years  ago  on  the  iron  contact  method.  He 
used  chiefly  briquettes  similar  to  those  suggested  by  Lewes,  made  of 
iron  oxide  and  clay  which  were  reduced  by  water  gas  in  iron  retorts, 
in  large  iron  retort  furnaces.  The  installations  proved,  however,  to  be 
of  inferior  working  capacity,  as  in  the  case  of  the  proposals  made 
by  Walker  (1890)  and  Hills  (1903),  and  were  nowhere  a  success. 
The  International  Hydrogen  Company,  whose  shares  are  held  by 
the  Berlin  Anhalt  Machine  Construction  Company  of  Berlin,  there- 
upon "  discovered "  the  identical  method  for  the  hundredth  time. 
The  result  was  the  same  as  in  all  other  previous  cases. 
The  inevitable  difficulty  of  the  retort  system  lies  in  the  fact  that 
