/ 
590  Notes  on  Solanaceous  Bases.  {AmNov.?i?£arm* 
the  atropine  salt.  It  was  anhydrous  and  had  the  same  composition  as  the  pre- 
viously-mentioned oxalates.  When  the  water  solution  of  the  sulphate  was 
mixed  with  platinum  chloride  and  evaporated,  an  anhydrous  platinum  salt  was 
obtained,  which  melted  between  2000  and  2040.  But  the  gold  salt  melted  at 
1540  to  1580,  according  to  the  sample  of  sulphate  from  which  it  was  obtained. 
By  recrystallization  the  melting-point  could  be  somewhat  raised,  and  crystal- 
line salt  was  obtained  from  the  mother  liquors  by  evaporation,  melting  at  1450 
and  even  less. 
It  was  evident  that  the  four  samples  of  sulphate  consisted  chiefly  of  hyos- 
cyamine  salt,  though  the  actual  amount  could  not  be  accurately  determined  as 
gold  salt.  This  can,  however,  be  done  by  the  optical  method.  For  that  pur- 
pose the  amount  of  water  is  to  be  first  ascertained  ;  so  that  a  definite  quantity 
of  anhydrous  salt  can  be  operated  upon.  Representing  the  quantity  of  atro- 
pine salt  in  the  unit  of  weight  by  x  and  that  of  the  hyoscyamine  salt  byj)/, 
their  respective  rotatory  power  for  solutions  of  equal  strength  by  a  and  b  and 
the  rotatory  power  of  the  sulphate  examined,  by  c,  the  amount  of  hyoscyamine 
salt  will  then  be  given  by  the  formula^  =  ~  and  the  amount  of  atropine 
b  —  a 
salt  by  x  =  1  —  c      a .   A  control  experiment,  with  known  quantities  of  atro- 
b  —  a 
pine  and  hyoscyamine  sulphates,  furnished  indisputable  evidence  of  the 
accuracy  of  this  method. 
The  data  given  above  suffice  to  show  this  mode  of  determining  the  two  bases. 
For  the  same  strength,  solvent,  and  temperature  it  was  found  that  a  =  8'8, 
b  =  28*6,  and  c  —  22*3,  i.e.,  the  rotary  power  of  the  mixed  sulphate  in  ques- 
tion. Substituting  these  values  in  the  formulae,  it  is  found  that  the  hyoscya- 
mine salt  amounts  to  o-682,  and  the  atropine  salt  to  o^iS.  Conseuuently  the 
salt  consisted  of  68*2  per  cent,  hyoscyamine  sulphate  and  31*8  percent,  atropine 
sulphate. 
In  a  similar  manner  the  relative  amounts  of  atropine  and  hyoscyamine  may 
be  determined  in  the  natural  atropine  or  in  other  mixtures.  Keeping  to  the 
above-mentioned  strength  of  the  alcoholic  solution  having  the  rotatory  power 
\_a\v>  =  —  i60,2,  the  amount  of  hyoscyamine  would  be  =  y  =  2SLA  °_4  — 
6*2  —  0-41 
0794  and  that  of  atropine  =  x  .==  1  —  0794  =  o-2o6. 
The  determination  of  the  bases  is  of  especial  importance  in  the  examination 
of  plants  yielding  them.  Schutte1  attempted  this  with  gold  chloride,  on  the 
assumption  that  the  hyoscyamine  salt  would  be  precipitated  first  and  then  the 
atropine  salt.  On  the  whole  that  is  correct  ;  but  the  former  salt  carries  with 
it  more  or  less  atropine  salt,  from  which  it  cannot  be  separated  without  con- 
siderable loss,  while,  on  the  other  hand,  some  l^oscyamine  remains  in  the 
solution  and  crystallizes  with  the  atropine  salt  in  a  warty  form.  Moreover,  the 
solution  will  contain  amorphous  substances,  which  sometimes  render  the 
detection  of  atropine  difficult,  if  not  impracticable.  This  may  have  been  the 
reason  why  van  Itallie2  was  unable  to  find  more  than  traces  of  atropine  in 
extract  of  belladonna. 
On  this  account  I  have  abandoned  that  method  in  determining  atropine,  and 
1  Mittheilungen  aus  dem  pharm.-chem.  Institut  der  Universitat  Marburg;  xii,  p.  596. 
Chem.  Centralbl.,  1892,  p.  390. 
