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PROPERTIES  OF  CARBO-AZOTIC  ACID. 
ON  THE  PHYSIOLOGICAL  AND  MEDICINAL  PROPERTIES  OF 
CARBO-AZOTIC  ACID. 
Br  Grace-Calvert  and  Dr.  J.  M.  Moffat. 
It  is  only  within  the  last  few  years  that  any  attempt  has  been 
made  to  make  use  of  the  remarkable  properties  which  this  acid 
presents,  discovered  by  M.  Welter,  and  so  well  described  by  M. 
Chevreul  in  1809. 
One  of  us  having  been  called  upon,  some  years  since,  to  seek 
a  method  of  preparing  carbo-azotic  acid,  which  should  be  con- 
stant in  its  results,  and  at  the  same  time  not  expensive,  adopted 
after  many  trials  the  process  recommended  by  Laurent,  as  being 
that  which  best  fulfilled  the  required  conditions ;  at  the  same 
time  we  have  to  state  that  great  precaution  is  necessary  to  obtain 
carbo-azotic  acid  free  from  indigotic  and  oxalic  acids. 
The  acid  which  we  prepared  is,  as  M.  Chevreul  has  said,  in 
small  plates  of  a  very  pale  yellow;  it  gives,  even  in  dilute  solu- 
tions, a  precipitate  with  salts  of  potash. 
The  intense  bitter  of  carbo-azotic  acid  suggested  the  idea  that 
its  employment  in  medicine  might  be  useful;  a  certain  quantity 
of  this  acid  as  well  as  of  the  carbo-azotates  of  ammonia,  iron, 
nickel,  and  zinc,  was  placed  in  the  hands  of  Dr.  Moffatt,  and 
soon  it  was  perceived  that  the  above-named  compounds  would  have 
therapeutic  properties  of  great  value,  for  they  had  much  analogy 
with  those  of  quinine. 
It  was  remarked  that  the  carbo-azotates  of  ammonia  and  of 
iron  succeeded  the  best,  the  free  acid  being  apt  to  cause  cramps 
in  the  stomach.  Carbo-azotate  of  iron  has  perfectly  succeeded 
in  several  cases  of  cephalalgia  ;  carbo-azotate  of  ammonia  in 
cases  of  anemia,  intermittent  fever,  and  hypochondria.  This 
salt  mixed  with  gallic  acid  and  opium  has  several  times  cured  ob- 
stinate diarrhoea.  Dr.  Moffat  has  himself  obtained  more  than 
twenty-seven  cases  of  different  cures  by  means  of  the  carbo- 
azotates.  The  dose  of  carbo-azotate,  which  has  been  adminis- 
tered in  pills,  has  been  from  0-05  to  0*10  gramme  per  day.  We 
are  at  present  examining  what  is  the  minimum  dose  which  can 
act  on  the  system.  That  which  renders  the  employment  of  these 
compounds  exceedingly  interesting  is,  that  the  patients  become 
yellow  as  if  they  had  a  severe  attack  of  jaundice,  and  as  in  this 
