.Am.  Jour.  Pharna,  "I 
■     April,  1882.  j 
Homatropine. 
14^ 
Even  after  a  few  hours  a  considerable  amount  of  the  base  is  formed 
and  when  the  action  of  the  hydrochloric  acid  is  continued  for  several 
<iays  on  the  water-bath,  a  good  yield  of  this  interesting  body  (about 
50  per  cent,  of  the  theoretical  amount)  is  obtained.  From  the  solu- 
tion in  hydrochloric  acid  potassium  carbonate  precipitates  an  oil  which 
does  not  solidify,  but  which  may  be  extracted  by  chloroform,  and^ 
after  the  removal  of  the  latter  by  distillation,  is  again  obtained  in  its 
original  state.  For  its  further  purification  it  is  dissolved  in  dilute 
hydrochloric  acid,  and  subsequently  precipitated  as  a  gold  double  salt 
or  as  picrate.  These  two  compounds  may  be  recrystallized  from  hot 
water  and  thus  obtained  perfectly  pure.  From  the  pure  gold  com- 
pound the  pure  homatropine  hydrochlorate  may  be  obtained  by  means 
of  hydrogen  sulphide.  From  the  picrate  the  base  may  be  again  sepa- 
rated by  dissolving  it  in  a  large  amount  of  hot  water,  so  that  it  remains 
dissolved  upon  cooling,  then  adding  an  excess  of  potassium  carbonate, 
and  agitating  with  chloroform.  This  is  again  shaken  with  a  solutiou 
of  potassium  carbonate  in  order  to  remove  the  last  traces  of  the  picrate, 
then  dried  over  potassium  carbonate,  and  distilled.  The  homatropine 
is  thus  always  obtained  in  the  form  of  an  oil,  and  the  attempts  of. 
Ladenburg  to  obtain  it  in  a  solid  or  crystalline  form  were  not  success- 
ful. More  recently,  however,  Merck,^  of  Darmstadt,  has  succeeded  in 
obtaining  it  in  transparent,  colorless  prismatic  crystals  from  its  solution 
in  absolute  ether.  The  crystals,  though  not  readily  soluble  in  water, 
are  nevertheless  hygroscopic  and  very  deliquescent;  their  melting 
point  is  between  95*5  and  98"5°C. 
Homati' opine- gold  chhy^idey  CigHgiNOg.HCl.AuClg,  is  usually  pre- 
cipitated as  an  oil,  but  soon  crystallizes,  and  may  be  recrystallized 
from  hot  water.  It  is  thus  obtained  in  handsome,  sparingly  soluble 
prisms. 
Hoinatropine-picrate,  CigH2iN03.CgH2(N02)30H.,  is  ^precipitated 
in  an  oily  or  resinous  form,  but  soon  becomes  crystalline.  It  dissolves 
readily  in. hot  water,  and  crystallizes  therefrom  in  yellow,  shining 
laminse. 
The  sul{)hate  and  hydrochlorate  are  also  crystal lizable  salts,  and 
the  acid  solution  of  the  latter  shows  the  following  l)ehavior  towards 
reagents:  tannic  acid  gives  no  turbidity ;  potassio-mercuric  iodide  a 
wliite  curdy  precipitate;  mercuric  chloride  a  white  oil,  and  solution  of 
^  "Ber.  d.  Deulsch.  Chem.  Ges.,"  1880,  p.  1340. 
