Aml™;wLim'}     Metallic  Derivatives  of  Cupreine.  409 
washings  are  free  from  nitric  acid;  lastly,  it  is  dried  at  ioo°  C.  The 
saffron  yellow  powder  should  not  yield  anything  to  alcohol  (absence 
of  gallic  acid)  and  should  yield  not  less  than  55  per  cent,  bismuth 
oxide  (theory  demands  56  66  per  cent.). — Pharm.  Ztg.,  1891,  400. 
Gymnemic  acid. — To  isolate  this  acid  the  finely  powdered  plant 
(Gymnema  silvestris)  is  moistened  with  a  small  quantity  of  20  per 
cent,  soda  solution,  allowed  to  stand  48  hours  and  extracted  for  24 
hours  with  benzin ;  the  benzin  is  distilled  off,  the  residue  repeatedly 
washed  with  ether  and  dried.  The  impure  acid  so  obtained  forms 
a  brownish  crystalline  powder,  very  soluble  in  alcohol,  in  100  parts 
water,  insoluble  in  ether,  chloroform  and  carbon  bisulphide  ;  acids 
decompose  it ;  it  forms  salts  which  are  not  soluble  in  water.  In 
larger  doses,  0-3-0-4,  it  is  emetic ;  in  very  small  quantities  it  is  very 
effective  in  disguising  bitter  tasting  medicines.  For  this  purpose  it 
is  recommended  to  use  an  one-half  per  cent,  aqueous  solution, 
to  which  is  added  a  small  quantity  of  alcohol  for  rinsing  the  mouth 
before  taking  the  medicine. — A.  Quirini  (Gyogysz.  Hetilap.)  Pharm. 
Ztg.y  1891,  401. 
METALLIC  DERIVATIVES  OF  CUPREINE.1 
By  A.  C.  Oudemans,  Jr. 
The  sodium  and  potassium  compounds  of  cupreine  separate  as 
crystalline  scales  when  a  solution  of  the  alkaloid  in  slight  excess  of 
the  corresponding  hydroxide  is  subjected  to  cold.  The  separated 
scales  are  dried  by  a  filter  pump,  washed  rapidly  with  strong  alcohol, 
and  placed  in  a  desiccator  over  potassium  hydroxide  for  some  time. 
Potassium  cupreine,  C19H21KN202  -f-  8H20,  forms  acicular  crystals  or 
hexagonal  scales.  Sodium  cupreine,  C19H21NaN202  -f-  5H20  and 
-f-  8H20,  forms  large  scales  which  are  greasy  to  the  touch.  The 
potassium  compound  appears  to  be  more  soluble  in  mixtures  of 
aqueous  and  alcoholic  alkalies  than  the  sodium  derivative. 
In  contradistinction  to  Hesse,  who  denied  the  existence  of  an 
ammonium  derivative  of  cupreine,  the  author  states  that  the  alka- 
loid dissolves  easily  in  concentrated  ammonia  solution,  to  a  smaller 
extent  in  weaker  solutions,  and  inasmuch  as  the  specific  rotatory 
power  of  such  solutions  is  similar  to  that  of  like  solutions  of  the 
sodium  derivative,  he  concludes  that  an  ammonium  compound  does 
1  Rec.  Trav.  Chim.,  9,  171-183  ;  reprinted  from  Jour.  Chem.  Soc,  1891,  471. 
