Am.  Jour.  Pharm.  ) 
January,  1915.  J 
Oxidation  of  Nitrogen. 
31 
The  nitride  (including  the  Serpek)  processes  have  not  as  yet 
proven  to  be  successful  from  the  commercial  point  of  view.  It  is  quite 
possible  that  these  methods  may  be  used  in  connection  with  the  manu- 
facture of  aluminum  and  other  metals  with  which  these  chemical 
methods  are  intimately  connected. 
The  Electrical  Methods  for  Fixing  Nitrogen. 
Several  electrical  methods  are  used  for  oxidizing  the  nitrogen  of 
the  air  into  nitric  acid  and  various  salts  of  nitrogen.  These  methods 
all  produce  chemical  reactions  between  gaseous  oxygen  and  nitrogen 
in  intense  electric  fields.  Potential  differences  of  thousands  of  volts 
are  used,  and  in  the  arc  methods  large  currents  and  high  temperatures 
accompany  the  use  of  intense  electric  fields,  In  all  these  methods 
the  aim  is  to  have  the  electrical  discharge  take  place  in  the  gaseous 
oxygen  and  nitrogen  and  to  eliminate  as  much  as  possible  the  effect 
of  the  metallic  electrodes.  Large  arcs  are  therefore  necessary  when 
the  electric  current  is  large.  In  the  Birkeland-Eyde  method  the  arc 
is  drawn  out  by  a  magnet ;  in  the  Schonherr  process  by  a  helical  cur- 
rent of  gas,  and  in  the  Pauling  process  by  horn  electrodes  and  currents 
of  gas.  In  the  author's  method  a  corona  current  is  used,  and  this 
seems  to  give  the  most  perfect  type  of  a  purely  gaseous  discharge. 
The  various  electrical  processes  give  about  the  same  order  of  effi- 
ciency when  this  is  measured  by  the  number  of  grammes  of  nitric 
acid  produced  per  kilowatt  hour  of  consumption  of  electrical  energy. 
About  60  to  80  Gms.  of  nitric  acid  are  formed  per  hour  per  kilowatt 
of  electrical  energy. 
The  Complexity  of  Chemical  Reactions. 
Although  single  atoms,  ions,  and  possibly  molecules  have  been 
isolated,  the  condition  under  which  the  isolation  takes  place  is  entirely 
unique,  the  particles  travelling  with  a  very  great  velocity.  In  general, 
chemical  reactions  will  not  take  place  under  these  conditions  in  any 
way  that  they  can  be  studied  individually.  Our  knowledge  of  chemi- 
cal reactions  is,  therefore,  entirely  statistical,  and  our  laws  apply  to 
a  very  large  number  of  reactions.  There  are  numerous  instances 
where  experimental  evidence  indicates  that  the  chemical  reactions 
are  frequently  complex.  The  speaker's  work  on  the  absorption  spec- 
tra of  uranyl  and  uranous  salts  indicated  the  possible  existence  of 
various  intermediate  compounds  in  chemical  reactions  in  solutions. 
In  gases  chemical  reactions  are  undoubtedly  much  less  complex 
