172 
Production  of  Nitric  Acid. 
( Am.  Jour.  Pharm. 
I       April,  1901. 
Many  attempts  at  the  artificial  production  of  nitrogen  compounds 
have  been  made,  from  time  to  time,  and  as  a  result  of  these  experi- 
ments it  was  found  that,  when  hydrogen  is  burned  in  oxygen  hav- 
ing an  admixture  of  a  small  quantity  of  nitrogen,  a  portion  of  the 
latter  combines  with  some  of  the  oxygen  to  produce  one  or  more 
of  the  oxides  of  nitrogen.  It  was  also  found  that  when  atmospheric 
air  in  a  glass  globe,  or  other  confined  space,  is  subjected  to  a  series 
of  electric  sparks,  red  fumes  of  nitrogen  tetroxide  were  formed. 
These  fumes,  in  the  presence  of  water,  are  decomposed  with  the  for- 
mation of  nitric  acid.  It  was  subsequently  learned  that  when  the 
air  is  compressed  the  production  of  red  fumes  is  materially  increased. 
This  combustion  of  atmospheric  air  by  means  of  induced  currents 
seems  to  indicate  the  solution  of  the  problem,  so  that  even  at  the 
present  time  it  would  seem  possible  that  nitrogen  compounds  might 
be  produced  economically  in  this  way. 
Sir  William  Crookes,  in  the  presidential  address  before  the  Brit- 
ish Association  for  the  Advancement  of  Science,  held  at  Bristol, 
England,  in  1898,  referred  to  this  particular  problem  at  some  length. 
He  made  especial  reference  to  the  necessity  of  the  nitrates  as  fertili- 
zers for  the  growth  of  cereals,  for  which,  it  is  estimated,  upward 
of  2,000,000  tons  are  used  annually.  In  the  course  of  this  address, 
Sir  William  Crookes  recounts  the  experiments  of  Lord  Rayleigh, 
who  had  tried  in  various  ways  to  effect  the  combustion  of  the 
nitrogen  in  atmospheric  air  for  the  purpose  of  separating  argon. 
From  the  data  furnished  by  Lord  Rayleigh's  experiments,  Sir 
William  Crookes  gives  some  interesting  figures.  He  estimates  that 
at  the  present  price  of  coal,  with  a  possible  conversion  of  10  per 
cent,  of  its  available  energy  into  electricity,  sodium  nitrate  might 
be  produced  at  about  $130  per  ton.  If,  on  the  other  hand,  the  initial 
cost  of  the  electric  current  -could  be  cut  down  to  one-fifth,  as  at 
Niagara  Falls,  it  would  reduce  the  cost  of  electric  sodium  nitrate  to 
$26  per  ton,  and  this  latter  figure,  with,  native  nitrate  quoted  at 
about  $37.50  per  ton,  would  seem  to  offer  a  fair  margin  of  profit. 
There  is  even  a  possibility  of  improving  on  these  figures.  Within 
a  year  or  two,  another  source  of  energy  has  been  suggested  that 
seems  destined  to  play  an  important  part  in  mechanical  and  in- 
dustrial development.  This  source  of  energy  is  derived  from  the 
conversion  of  blast  furnace  gases  into  power  by  means  of  a  new 
style  gas  engine  that  has  been  introduced  at  some  of  the  larger 
