HUMOID  CONSTITUENTS  Of  THE  CINCHONA  BARKS.  171 
borate  of  soda,  decompose  iodide  of  potassium  at  a  high  tem- 
perature, and  the  violet  vapors  only  make  their  appearance  at 
nearly  a  red  heat. 
Sulphate,  phosphate  and  carbonate  of  lime,  by  the  action  of 
heat  and  air,  partially  decompose  iodide  of  potassium  ;  but  bin- 
oxide  of  manganese,  by  the  simple  action  of  heat,  eliminates  all 
the  iodine  of  the  iodide. 
Carbonate  and  nitrate  of  potash,  and  carbonate  of  soda  have 
no  decomposing  action  upon  iodide  of  potassium. 
Cantu  announced  the  decomposition  of  iodide  of  potassium  at 
a  high  temperature  in  a  current  of  dry  nitrogen,  but  this  ex- 
periment repeated  several  times,  never  furnished  the  least  evolu- 
tion of  violet  vapors. — Chemical  Cfazette,  from  Comptes  Eendus, 
August  22,  1859. 
ON  THE  HUMOID  CONSTITUENTS  OF  THE  CINCHONA  BARKS. 
By  0.  Hesse. 
In  the  investigation  of  the  Huanoco  Cinchona  bark,  Reichel 
found  a  brown  matter,  the  properties  of  which  differed  from  those 
of  humic  acid  of  peat,  and  to  which  he  gave  the  name  of 
lignoine. 
Analyses  of  lignoine  dried  at  212°  F.,  made  by  Hesse,  gave 
C  594  59.2  40  59-25 
H  6-1  5-6  23  5.6T 
N  3.5  .  .  1  347 
0  .  .  .  .  16 
Lignoine,  C^^H^^NO^^,  dissolves  very  readily  in  alkaline  car- 
bonates, and  these  solutions  absorb  no  oxygen;  in  other  respects 
it  differs  but  little  from  the  humoid  substances. 
The  nitrogen  expressed  in  the  preceding  analysis  is  contained 
in  the  form  of  ammonia,  which  is  set  free  by  boiling  with  caustic 
potash,  when  a  body  of  the  composition  C^'^H^'^0^^  is  obtained. 
This  body,  therefore,  is  distinguished  by  its  composition  from 
the  humoid  bodies  of  vegetable  mould  and  peat,  as  it  contains 
four  atoms  of  hydrogen  more  than  of  oxygen. 
The  Chinova-red  prepared  by  Hlasiwetz  has  the  same  com- 
