82 
The  Assay  of  Cinchona  Bark. 
J  A_m.  Jour.  Pharm. 
\   February,  1896. 
ents.  This  is,  undoubtedly,  due  to  the  presence  of  the  gummy  extrac- 
tive matter,  which,  when  treated  as  above,  agglutinates  into  small  par- 
ticles that  envelope  the  alkaloids.  These  small  particles  being 
insoluble  in  the  menstruum  employed,  makes  it  impossible  to  recover 
the  alkaloids  so  occluded.  In  connection  with  the  sulphuric  acid, 
Dr.  A.  B.  Lyons  employs  ether,  which  appears  to  facilitate  the 
extraction  somewhat. 
Process. 
Percent,  of  alkaloids  in 
Cinchona  Calisaya. 
Percent,  of  alkaloids 
in  Fluid  Extract  Cin- 
chona Calisaya. 
1 
2 
3 
Average. 
1 
2 
Average. 
U.  S.  P.,  1890  
Chloroform-ether  .  .  . 
8  20 
9*57 
7 '99 
9"3i 
8'20 
9-40 
8-  13 
9-  42 
5*8o 
6-41 
6'oo 
6*39 
5*90 
6-40 
Percent,  of  alka- 
Percent, of  alka- 
Percent, of  alka- 
loids  in  Fluid 
loids   in  Fluid 
Process. 
loids    in  Cin- 
Extract   C  i  n  - 
Extract    C  i  n  - 
chona  Rubra. 
chona  Rubra, 
No.  I. 
chona  Rubra, 
No.  II. 
U.  S.  P.,  1890   .  . 
4*57 
2-43 
Prollius  
4'56 
2 '57 
Lyons,  No.  i1   .  . 
479 
2 '49 
Lyons,  No.  21   .  . 
573 
2'39 
3-89 
Lyons,  No.  i2   .  . 
4"97 
Lyons,  No.  22   .  . 
Haubensak    .  .  . 
5-8i 
3"5i 
3  "93 
5*96 
3 '43 
3"97 
Haubensak  and 
Kiirsteiner    .  . 
5 '90 
3*59 
Haubensak  and 
Keller  
5'27 
3'6i 
Chloroform  -  ether 
577 
3'50 
4-07 
1  Prollius'  mixture.  2  Prollius'  fluid,  modified. 
The  writer  has  frequently  treated  the  gummy  residue  with  an 
undue  amount  of  water,  but  the  filtrate,  when  tested  for  alkaloids, 
.always  responded  affirmatively.  In  view  of  this  fact,  the  following 
•experiment  was  made  :  the  gummy  residue  was  washed  with  water 
until  the  filtrate  was  only  slightly  acid  to  litmus  paper;  this  re- 
quired about  180  c.c,  The  filtrate  was  now  collected  in  a  graduated 
cylinder.  After  the  first  100  c.c.  were  obtained,  the  issuing  filtrate 
was  tested  by  both  Wagner's  and  Mayer's  reagents ;  both  gave 
