624  The  Alkaloids  of  Dira  Bark,         { ■^"•r!e°?.?i88o""^. 
residue  show  here  and  there  indications  of  crystallization.  Upon  dis- 
solving this  residue  in  strong  alcohol,  or  in  a  mixture  of  equal  parts  of 
acetone  and  water,  the  pure  base  is  obtained  upon  spontaneous  evapora- 
tion or  ihe  solution  in  a  chamber  free  from  carbonic  acid  in  thick 
obliquely  truncated  glassy  prisms. 
An  analysis  of  the  air-dried  substance  gave  results  corresponding  with 
the  formula  C22H28N2O4+4H2O.  Upon  placing  the  air  dried  crystals- 
in  an  exsiccator  they  lost  I  molecule  of  water;  when  further  dried  in 
a  partial  vacuum  (about  400  mm.)  at  8o°C.  they  lost  2  molecules  more,, 
and  the  fourth  molecule  was  given  ofF  with  difficulty,  and  after  some 
time,  upon  raising  the  temperature  to  I05°C.  Upon  exposure  to  moist 
air  this  anhydrous  substance  quickly  took  up  i  molecule  of  water,  again 
forming  the  compound  C22H28N204-(-H20.  The  same  compound  is 
obtained  upon  treating  the  residue  left  by  the  evaporation  of  the  ethereal 
or  chloroform  solution  with  hot  acetone.  The  basic  mass  at  first  swells 
up,  and  is  eventually  converted  into  a  magma  of  delicate  white  amor- 
phous flocks,  which,  washed  with  cold  acetone,  dried  in  an  exsiccator 
and  pulverized,  form  a  white  powder,  having  the  composition  of  the 
monohydrate. 
The  last  traces  of  the  last  molecule  of  water  are  very  persistent,  and 
can  scarcely  be  got  rid  of  without  decomposition  taking  place.  More- 
over, the  dry  residue  obtained  at  I05°C.  is  almost  without  action  upon 
red  litmus  paper,  whilst  that  containing  1  molecule  of  water  sharply 
colors  such  paper  blue.  It  would  consequently  appear  that  this  I 
molecule  of  water  has  a  special  signification  towards  echitamine,  and 
that  by  its  loss  a  much  weaker  base  is  formed  from  a  strong  one. 
This  substance  formed  by  drying  at  I05°C.  has,  however,  the  pecu- 
liarity that  when  treated  with  hydrochloric  or  other  acids  the  original 
base  is  again  formed.  This  recalls  in  some  measure  the  formation  of 
chloride  of  ammonium  when  hydrochloric  acid  and  ammonia  are 
brought  together.  But  when  chloride  of  ammonium  is  decomposed  with 
potassium  hydrate  the  nitrogen  base  splits  up  into  ammonia  and  water, 
whilst  in  the  case  of  the  organic  base  under  consideration,  when  it  is 
decomposed  with  potassium  hydrate,  the  water  remains  combined,  and 
is  only  given  off  upon  the  application  of  heat. 
C22H28N20,.HCi+KHO==KCl+C22H28N204.H(HOj. 
Consequently,  the  author  calls  the  compound  with  one  molecule  of 
wattr,  C22H28N204'H20,     echitammoniumhydroxide,"  yieldmg  echi- 
tamine by  the  loss  of  i  molecule  of  water. 
