^'"bSr:8?o?''"'}         T-^he  Alkaloids  of  Bit  a  Bark.  623 
•centrated  acetic  solution  of  ditamine  a  few  drops  of  strong  hydrochloric 
acid  be  added  it  lemains  perfectly  clear,  whilst  in  a  similar  solution  of 
echitamine  a  dense  crystalline  precipitate  is  soon  formed,  the  com- 
mencement of  which  is  promoted  by  stirring  the  liquid  with  a  glass  rod. 
T^he  small  quantity  of  ditamine  at  the  author's  disposal  did  not  allow 
of  the  composition  of  the  free  base  being  ascertained  by  analysis;  but 
the  platinum  salt,  obtained  in  light  yellow  amorphous  flocks  by  pre- 
cipitating an  aqueous  hydrochloric  solution  with  platinum  solution,  gave 
figures  corresponding  with  the  formula  (C^gH^gN  02,HCl)2-l-PtCl4. 
The  free  alkaloid  would  therefore  have  the  formula  CjgHj9N02. 
Echitamine. — After  the  ditamine  has  been,  in  the  way  described, 
removed  as  entirely  as  possible,  the  remaining  solution  is  neutralized 
with  acetic  or  sulphuric  acid,  and  carefully  evaporated  until  it  equals 
one-fifteenth  to  one-twentieth  the  weight  of  the  bark  used.  To  the 
solution,  whilst  still  warm,  some  hydrochloric  acid  and  chloride  of 
sodium  is  added,  which  produces  a  resinous  precipitate  that  soon 
becomes  crystalline.  The  addition  of  sodium  chloride  is  continued 
until  it  is  observed  that  the  precipitated  resin  no  longer  alters  its  form 
upon  standing.  After  24  hours  the  precipitate  is  collected,  washed 
with  concentrated  hydrochloric  acid  and  purified  by  crystallization  from 
boiling  water.  As  hydrochlorate  of  echitamine  is  almost  insoluble  in 
concentrated  hydrochloric  acid,  the  crystallization  from  water,  which, 
as  a  rule,  is  rather  slow,  may  be  hastened  by  adding  hydrochloric  acid 
to  the  solution.  The  hydrochlorate  is  then  thrown  down  as  a  white 
crystalline  powder. 
Echitamine  may  also  be  prepared  by  adding  fused  potash  to  the 
before-mentioned  basic  aqueous  solution  that  remains  after  the  removal 
of  the  ditamine  and  shaking  with  chloroform.  The  chloroform  takes 
up  the  alkaloid  present,  which  is  partly  suspended  and  partly  in  solu- 
tion, and  gives  it  upon  evaporation  as  an  amorphous  residue,  which, 
upon  treatment  with  a  little  concentrated  hydrochloric  acid,  very  easily 
yields  the  hydrochlorate  pure. 
From  the  pure  salt  the  free  alkaloid  can  easily  be  obtained  by  dis- 
solving it  in  the  smallest  possible  quantity  of  hot  water,  adding  to  the 
solution  saturated  solution  of  potash,  or  preferably  fused  potash,  and 
shaking  out  the  free  base,  which  separates  in  white  flocks,  with  tther 
or  chloroform.  In  either  case  there  remains  after  slow  evaporation  an 
amorphous  residue,  which,  upon  drying  in  the  exsiccator,  at  first 
shrivels  up  and  then  cracks.    Only  in  very  exceptional  cases  does  this 
