424 
Hydrogen  Peroxide. 
(Am.  Jour.  Puarm 
1  September,  1902. 
HYDROGEN  PEROXIDE.1 
By  Robert  C.  Purser. 
Insufficient  time  has  prevented  me  from  experimenting  with  the 
making  of  hydrogen  peroxide  in  a  small  way.  Having  been  for 
several  years  connected  with  a  firm  who  manufactured  hydrogen 
peroxide  extensively,  and  it  being  part  of  my  duties  to  assay  the 
finished  product,  I  do  not  think  that  it  can  be  prepared  in  a  small 
way  profitably.  So  many  firms  are  making  it  to-day  and  competi- 
tion is  so  keen  that  the  pharmacist  is  now  enabled  to  buy  hydrogen 
peroxide,  conforming  to  the  U.S. P.  requirements,  at  a  reasonable 
price. 
All  the  barium  dioxide  used  in  this  country  to-day  has  to  be 
imported  ;  usually  it  is  shipped  in  strong  casks  containing  about  1200 
pounds.  This  quantity  would  last  the  average  pharmacist  for  a 
considerable  length  of  time,  and  I  think  before  the  last  of  it  was 
used  up  it  would  begin  to  get  hard  and  lumpy  and  difficulties  would 
be  experienced  in  working  it. 
By  using  phosphoric  acid,  as  the  U.S. P.  directs,  it  is  almost  impos- 
sible to  get  a  product  that  assays  10  volumes  of  available  oxygen. 
Some  manufacturers  use  hydrofluoric- acid  (this  may  be  ascertained 
by  applying  the  U.S. P.  test  for  the  acid),  and  this  would  necessitate 
suitable  apparatus.  The  operation  would  also  have  to  be  performed 
away  from  shelf-bottles  and  all  glassware,  else  they  would  in  a  short 
time  become  beautifully  etched.  The  acidity  of  a  large  quantity  of 
hydrogen  peroxide  can  be  adjusted  as  easily,  and  probably  better 
than  that  of  a  small  quantity.  Altogether  there  is  a  great  deal  to 
know  about  the  making  of  hydrogen  peroxide  that  cannot  be  found 
in  textbooks,  and  the  average  pharmacist  would  encounter  great  dif- 
ficulties if  he  attempted  the  making  of  hydrogen  peroxide. 
Njarly  all  of  the  manufacturers  of  hydrogen  peroxide  bottle  it 
from  a  half  to  one  volume  above  what  their  label  calls  for.  In  this 
way  it  will  keep  under  proper  conditions  for  quite  awhile  and  still 
conform  with  their  label. 
Four  different  makes  of  hydrogen  peroxide  were  obtained,  assayed 
the  day  they  were  received,  recorked  and  kept  in  the  cellar  for 
about  six  months ;  they  were  then  assayed  with  the  following 
results : 
1  Read  at  the  annual  meeting  of  the  Pennsylvania  Pharmaceutical  Associa- 
tion, June,  1902. 
