526       Mr.  J.  A.  Wanklyn  on  Water- Analysis  and  Water. 
alone  is  the  process  applicable  to  drinking-water,  but  Dr.  Angus 
Smith  has  used  it  in  a  most  elaborate  investigation  of  the  atmo- 
sphere, and  Dr.  Ransome  in  investigating  the  breath  in  different 
diseases  ;  and  I  have  in  view  a  very  wide  and  general  use  of  it 
in  physiological  chemistry. 
The  "  ammonia  process  "  consists  in  oxidizing  organic  sub- 
stances in  a  strongly  alkaline  solution,  and  measuring  the  am- 
monia yielded  by  oxidation  under  such  conditions. 
The  oxidizing  agent  hitherto  employed  by  us  in  working  the 
process  has  been  permanganate  of  potash,  which  is  very  conve- 
nient and  manageable,  and  has  the  great  advantage  of  not  at- 
tacking the  ammonia  which  is  produced.  An  investigation  of 
the  action  of  other  oxidizing  agents  in  alkaline  solution  would 
repay  the  trouble  of  making  it,  and  may  possibly  be  undertaken 
at  some  future  time. 
We  have  submitted  a  large  number  of  nitrogenous  organic 
substances,  exhibiting  the  utmost  diversity  of  structure,  to  the 
action  of  strongly  alkaline  permanganate,  and  obtained  ammonia 
as  a  product  of  the  action.  Quoting  from  a  paper  published  by 
the  Chemical  Society  {vide  Journ.  Chem.  Soc.  ser.  2,  vol.  vi. 
p.  170),  "The  compound  ammonias  of  all  kinds,  the  amides 
of  the  acids,  such  substances  as  piperine,  hippuric  acid,  creatine, 
the  natural  alkaloids,  albumen,  gelatine,  and  uric  acid  evolve 
ammonia  when  treated  in  this  way.  Even  so  tough  a  substance 
as  picoline,  which,  as  is  well  known,  is  one  of  the  most  stub- 
born of  organic  compounds,  yields  ammonia  when  subjected  to 
this  treatment." 
An  elaborate  investigation  carried  out  with  the  express 
object  of  ascertaining  if  there  were  organic  compounds  con- 
taining nitrogen  which  yield  no  ammonia  on  boiling  with  the 
permanganate  in  alkaline  solution,  has  given  the  following  re- 
sults : — 
Nitro-  com  pounds  do  not  yield  their  nitrogen  in  the  form 
of  ammonia  in  this  reaction.  That  such  would  be  the  case 
might  almost  have  been  concluded  a  priori ;  for  an  oxidation 
is  not  calculated  to  convert  nitric  oxides  into  ammonia.  It 
is  satisfactory,  however,  to  have  direct  experimental  evidence. 
The  case  investigated  was  picric  acid,  which  gave  nitric  acid  on 
treatment  with  the  permanganate,  but  no  ammonia.  Ferrocy- 
anide  of  potassium  failed  to  give  ammonia,  probably  in  virtue  of 
its  extreme  toughness.  Urea  failed  to  give  ammonia  on  oxida- 
tion in  alkaline  solution  of  permanganate.  These  were  the  only 
cases  wherein  organic  nitrogenous  substances  failed  to  give  am- 
monia on  being  boiled  with  permanganate  of  potash.  The  case 
of  urea  is  particularly  interesting.  On  inspection  of  its  formula, 
it  will  be  perceived  that  it  contains  less  hydrogen  than  is  re- 
