55o 
Te clinical  Chemistry. 
/Am.  Jour.  Pharm. 
I  November,  1900. 
S03,  by  the  contact  power  of  finely-divided  platinum  on  a  mixture 
of  sulphurous  oxide  and  air.  This  reaction  was  long  ago  discovered 
by  Winkler  and  utilized  for  making  dry  sulphuric  trioxide  and 
fuming  acid,  but  the  heat  produced  soon  checked  the  reaction,  and 
the  converting  power  of  the  platinum  soon  gave  out.  The  experts 
of  the  Badische  Anilin  and  Soda  Manufacturing  Company,  a  few 
years  ago,  discovered  the  cause  of  the  latter  trouble  to  be  the  pres- 
ence of  dust  and  foreign  gases,  principally  arsenic  and  phosphorus 
compounds,  and  much  moisture.  By  using  purified  gas  and  provid- 
ing a  way  of  escape  for  the  excess  of  heat  generated  by  the  reac- 
tion, the  process  became  quantitative,  even  with  dilute  sulphurous 
anhydride,  and  hence  commercially  possible  for  making  all  kinds  of 
sulphuric  acid.  Many  German  acid  makers  are  reported  to  be 
rapidly  eliminating  their  lead  chambers  and  using  platinized  asbes- 
tos or  pumice-stone  instead.  The  new  method  is  especially  economi- 
cal for  the  strongest  acids,  the  stronger  the  acid  to  be  made  the 
greater  the  economy  over  the  nitre  method.  Weaker  acids,  up  to 
chamber  acid  strength,  are  probably  still  made  much  more  cheaply 
by  present  methods.  The  new  process  is  best  also  for  making  the 
purer  grades,  for,  by  using  pure  sulphurous  gas,  chemically  pure 
acid  can  be  made  as  cheaply  as  any  other. 
The  latest  antagonist  by  which  the  old  salt-cake  and  muriatic 
acid  soda  and  bleach  industry  has  been  assailed,  namely,  the  elec- 
trolytic process  of  chlorine  and  soda  production,  has,  during  the  past 
year,  developed  into  such  a  giant  that,  with  its  older  competitor,  the 
ammonia-soda  process  ever  enlarging,  the  death  of  the  LeBlanc 
process  cannot  be  postponed  many  years.  Only  in  Great  Britain 
does  the  process,  by  virtue  of  the  retaining  energy  of  im- 
mense capital  invested,  survive  to  any  considerable  extent.  On  the 
European  continent  ammonia  soda  had  practically  expelled  it  with- 
out the  assistance  of  electrolytic  methods.  In  this  country  it  never 
had  a  foothold.  In  England  it  has  survived  mainly  because  of  the 
profit  on  the  chlorine  industries.  Now  electrolytic  methods  have 
removed  this  last  prop,  producing  bleach  as  cheaply  as  the  value  of 
the  hydrochloric  acid  used  in  the  older  processes.  No  competition 
is  really  ever  likely  to  exist  between  the  ammonia  soda  and  electro, 
lytic  processes,  because  the  soda  produced  by  electrolysis  is  of  little 
worth  compared  with  the  value  of  the  halogen.  The  electrolytic 
production  from  salt  of  all  the  bleach  used  would  produce  only  an 
