Am.  Jour.  Pharm.") 
Jan.,  1884.  J 
Tincture  of  Nux  Vomica. 
33 
but  inasmuch  as  the  residue  will  not  dissolve  in  chloroform  alone 
15  cc.  of  dilute  sulphuric  acid  (5  per  cent.)  are  added,  and  the  mixture 
is  poured,  after  gently  warming,  into  a  separating  funnel,  well  shaken, 
and  the  chloroform  run  off ;  the  latter  is  extracted  with  a  little  more 
acid  if  necessary.  The  acid  liquid,  which  contains  the  alkaloid,  is 
rendered  alkaline  with  ammonium  hydrate  and  agitated  with  15  cc.  of 
chloroform,  which  is  separated  and  filtered  if  necessary.  The  alkaline 
liquid  is  again  shaken  with  chloroform  and  the  latter  run  off.  The  mixed 
chloroformic  solutions,  which  should  be  perfectly  clear,  are  evaporated 
to  dryness  upon  the  water-bath,  and  after  exposure  for  one  hour  at  this 
temperature  the  residue  of  total  alkaloid  is  weighed. 
In  many  cases  the  residue  from  the  evaporation  of  the  tincture  may 
be  directly  dissolved  in  dilute  sulphuric  acid,  the  liquid  rendered  alka- 
line with  ammonium  hydrate  and  the  alkaloid  extracted  with  chloro- 
form. In  certain  cases,  however,  the  alkaloid  obtained  in  this  way 
contains  a  trace  of  coloring  matter,  but  a  perfectly  pure  residue  is 
obtained  by  the  method  described  at  length  above. 
The  following  table  shows  the  results  of  the  experiments : 
TABLE  I. 
Proportion  of  rectified  spirit 
to  water  (by  volume). 
Quantity  of  total  alkaloid  in 
40  cc.  of  tincture. 
Percentage  of  total  alka- 
loid  extracted  from  the 
nux  vomica. 
100  :  0 
(rectified  spirit) 
]00  :  25 
100  :  33 
100  :  50 
100  :  60 
(proof  spirit) 
100  :  100 
0-078 
0-088 
0-088 
0-089 
0'086 
0-074 
1-  95 
2-  20 
2-20 
2-22 
2-15 
1-85 
The  marcs  from  these  tinctures  were  found  in  all  cases  to  be  dis- 
tinctly bitter,  and  hence  in  no  case  had  the  exhaustion  been  complete. 
The  above  results  show  that  water  mixed  with  rectified  spirit  in  any 
proportion  up  to  and  including  proof  spirit  extracts  more  alkaloid  than 
rectified  spirit  alone ;  but  when  the  water  rises  above  the  proportion 
contained  in  proof  spirit  the  extractive  power  for  alkaloid  again 
diminishes.    The  obvious  conclusion  to  be  drawn  from  these  experi- 
3 
