172  PREPARATION  OF  SUBNITRATE  OF  BISMUTH. 
position  as  the  substance  when  free  from  ammonia.  In  this 
HIasiwetz  found 
C  6M0  61.32 
H  6.05  5.26 
Phlobaphene  also  belongs  here.  For  this  body  the  formula 
Q2ogioQ8  \^iq\j  proposed.  Reichel  also  obtained  from  red 
Cinchona  bark  a  brown  matter  (which  he  calls  a  lignoine-like 
body)  containing 
C  61.15 
H  4.65(?) 
The  latter  substance,  however,  contains  some  ammonia,  as 
appears  from  Reichel's  further  experiments. 
It  consequently  appears  that  a  brown  humoid  matter  of  the 
same  composition  is  deposited  in  the  Cinchona  barks,  which  may 
be  expressed  by  the  formula  C'^H.-^O^^  It  is  essentially  distinct 
from  the  China-red  of  Schwarz,  and  not  to  be  classed  with  this, 
as  has  been  done  by  Gerhardt.  It  is,  however,  remarkable, 
that  in  this  humoid  matter  we  again  meet  with  the  group  C^^H^^, 
which  makes  its  appearance  if  we  attribute  to  quinine  the 
formula 
London  Chem,  Qaz.  from  Liehig's  Annalen.  cix. 
PREPARATION  OF  SUBNITRATE  OF  BISMUTH. 
MM.  Bechamp  and  C.  St.  Pierre  recommend  the  following 
method  of  making  subnitrate  of  bismuth  (Montpelier  Medicaid 
April,  1860.)  They  first  make  a  neutral  nitrate,  by  pouring 
nitric  acid  on  powdered  bismuth.  The  crystals  of  this  neutral 
salt  are  drained,  and  then  washed  with  a  mixture  of  1  part  of 
acid  and  3  of  water.  They  are  then  dissolved  in  as  small  a 
quantity  as  possible  ;  and  the  experiments  of  the  authors  have 
shown  that  a  cubic  centimetre  of  water,  at  80^,  containing  10 
per  cent  of  nitric  acid,  is  sufficient  to  dissolve  1  gramme  of  the 
salt.    12  J  parts  of  water,  are  now  sufficient  to  precipitate  a  part 
