OXYGENNESIS,  FOR  THE  PRODUCTION  OF  OXYGEN,  ETC.  243 
this  process,  instead  of  being  thrust  in  the  rear,  would  have 
taken  front  rank. 
Oxygennesis,  therefore,  stands  alone  as  a  novel  and  the  only 
mode  we  possess  for  producing  oxygen  without  the  application 
of  heat.  The  mode  of  using  this  compound  is  extremely  sim- 
ple. We  have  only  to  take  some  of  this  powder,  place  it  in  a 
glass  flask  or  bottle  provided  with  an  exit  tube,  pour  on  any 
of  the  dilute  mineral  acids,  and  we  have  immediately  oxygen 
evolved  in  a  similar  way,  and  with  as  much  facility,  as  hydrogen 
is  obtained  from  zinc  or  carbonic  acid  from  a  carbonate. 
The  composition  of  this  compound  is  extremely  simple,  merely 
peroxide  of  barium,  and  bichromate  potash.  Not  so  the  chemi- 
cal changes  resulting  from  an  addition  of  an  acid.  Peroxide 
of  barium,  on  addition  of  sulphuric  acid,  is  resolved  into  sul- 
phate of  baryta  and  peroxide  of  hydrogen,  and  it  is  from  this 
sometimes  so-called  oxygenated  water  we  get  this  curious  and 
interesting  chemical  reaction.  Whenever  peroxide  of  hydrogen 
and  chromic  acid  are  brought  into  contact  with  each  other,  in- 
stantaneous decomposition  is  the  result,  the  chromic  acid  is  re- 
duced to  sequioxide  of  chromium,  and  the  peroxide  of  hydro- 
gen to  water ;  at  the  same  time  pure  oxygen  derived  from  both 
those  substances  is  disengaged.  The  theory  of  this  very  inter- 
esting reaction  is  not,  I  believe,  well  understood,  and  I  know 
only  one  way  of  explaining  it,  that  is,  on  the  ozone  and  anto- 
zone  theory  of  Brodie.  According  to  that  theory,  oxygen  ex- 
ists in  three  different  states  or  conditions,  viz.,  ozone,  antozone, 
and  ordinary  oxygen,  and  whenever  ozone  and  antozone  (which 
may  both  be  considered  more  or  less  active)  are  brought  to- 
gether, they  unite  and  neutralize  each  other,  as  it  were  forming 
passive  or  common  oxygen. 
To  return  to  the  composition  of  the  powder,  we  are  not  com- 
pelled to  use  precisely  those  ingredients  mentioned,  but  may 
substitute  analogous  compounds.  Peroxide  of  barium  might  be 
replaced  by  any  other  peroxide  capable  of  forming  binoxide  of 
hydrogen,  of  which  there  are  several — peroxides  potassium,  so- 
dium, strontium,  and  calcium — but  all  these  at  the  present  time 
are  practically  useless,  peroxide  of  barium  being  the  only  one 
that  can  be  easily  and  cheaply  prepared.  Bichromate  of  potash 
may  be  substituted  by  manganate  or  permanganate  of  potash, 
