Am.  Jour.  Pharm. 
August,  1914. 
Criticism  of  U.  S.  Pharmacopoeia, 
347 
In  explanation  of  the  table  it  should  be  stated  that  Schmidt  and 
Gadamer  determined  the  melting-points  of  the  various  salts,  using  a 
capillary  tube  and  sulphuric  acid  bath ;  Hesse  used  a  "  Roth's  " 
apparatus.  Schmidt  found  the  melting-point  of  the  chloraurate  of 
the  1-  salt  to  be  208 °  to  209 0  when  determined  with  the  "  Roth's  " 
apparatus.42 
TABLE  NO.  4- 
Pharmacopoeia. 
Per  cent,  of  H2O  lost  in  dry- 
ing at  ioo°  C.  or  over  H2SO4 
M.  P.  of  the 
anhydrous  salt. 
M.  P.  of  the 
chloraurate. 
Specific  rota- 
tory power  of 
a  5  per  cent, 
aqueous  solu- 
tion at  15°  C 
United  States43.  . 
British44  
179-7° 
1 93- 1 94° 
About  1900 
197° 
198° 
More  than  12  per  cent. 
12.3  per  cent. 
German45  
-24°  45' 
A  comparison  of  the  constants  as  given  in  Tables  No.  3  and  No.  4 
shows  the  melting-point  (179.70  C.)  of  the  anhydrous  hydrobromide 
as  specified  in  the  United  States  Pharmacopoeia  to  agree  very  closely 
with  that  (1800  C.)  found  by  Schmidt  or  Hesse  (1810  C.)  for  i- 
scopolamine  hydrobromide;  while  the  melting-point  (1970  C.)  of 
the  chloraurate  as  given  in  the  pharmacopoeia  corresponds  very  well 
with  that  (1980  C.)  found  by  Hesse  for  the  chloraurate  of  1-scopo- 
lamine.  According  to  two  observers,  the  melting-point  of  the  hydro- 
bromide alone  is  no  indication  as  to  the  respective  quantities  of  the 
1-  and  i-isomers  present  in  the  commercial  salt ;  e.g.,  Schmidt46  found 
a  melting-point  of  i8o°-i8i°  C.  for  the  commercial  hydrobromide, 
[a]D  =  —  130  30';  Hesse47  obtained  a  melting-point  of  1780  C.  for 
a  sample  of  the  hydrobromide,  [a]D  =  —  21. 30.  If  we  take  into 
consideration  the  fact  that  the  hydrobromides  of  both  the  lsevo-  and 
the  inactive  forms  crystallize  with  3H0O,  and  that  the  melting-points 
of  the  chloraurates  have  not  yet  been  definitely  established,  it  be- 
comes evident  that  the  pharmasppoeial  tests  for  the  identity  of  this 
compound  are  worthless. 
That  physical  constant  which  has  been  found  to  give  the  most 
accurate  indication  as  to  the  purity  of  1-scopolamine  or  its  salts, 
42  Arch.  d.  Phar.  (1894),  232,  p.  417. 
43  U.  S.  P.,  8th  Rev.  (1905),  P-  39L 
"British  P.  (1898),  p.  153. 
45  Deutsches  Arzneibuch,  5th  Edit.,  Berlin  (1910),  p.  451. 
48  Arch.  d.  Pharm.  (1898),  236,  p.  62. 
47  Jour n.  f.  prakt.  Chan.  (1901),  64,  2,  p.  385. 
