$28  Tincture  of  Nux  Vomica.  {^*S£&vK' 
adjusted,  by  the  addition  of  menstruum,  to  represent  2  per  cent, 
of  anhydrous  extract. 
In  the  U.  S.  P.  of  1890,  the  tincture  was  directed  to  be  made  by 
dissolving  20  grammes  of  an  anhydrous  extra :t  of  nux  vomica  con. 
taining  15  per  cent,  of  alkaloids,  in  a  sufficient  quantity  of  a  mixture 
of  three  volumes  of  alcohol  and  one  volume  of  water  to  make  1000 
c.c.  Each  100  c.c.  contained  0  3  gramme  of  total  alkaloids.  It 
was  assumed  that  the  strychnine  and  brucine  were  present  in  the 
total  alkaloids  in  about  equal  proportion,  which  would  indicate  that 
each  100  c.c.  of  tincture  represented  0-15  gramme  of  strychnine. 
As  a  matter  of  fact,  this  assumption  was  in  error,  the  percentage  of 
strychnine  in  the  total  or  mixed  alkaloids  being  from  one-third  to 
one-half. 
In  the  U.  £>.  P.  of  1900  (8th  Revision),  20  grammes  of  a  standard- 
ized extract  of  nux  vomica  containing  $  per  cent,  of  strychnine 
is  directed  to  be  dissolved  in  a  sufficient  mixture  of  three  volumes 
of  alcohol  and  one  volume  of  water  to  make  1000  c.c.  Each  100 
c.c.  contains  01  gramme  of  strychnine,  which,  apparently,  is  a 
reduction  in  the  strength  from  the  former  revision  of  about  20  per 
cent. 
It  is  to  be  regretted  that  the  present  issue  of  the  U.  S.  Pharma- 
copoeia saw  fit  to  continue,  practically,  the  formula  of  the  previous 
revision,  although  an  attempt  has  been  made  to  secure  a  more  defi- 
nite product  by  using  an  extract  standardized  to  contain  five  per 
cent,  of  strychnine.  This  extract,  which  is  in  a  powdered  form,  is 
expensive  and  tedious  to  make,  readily  solidifies  (which  is  due  to 
the  sugar  of  milk  present),  and  when  mixed  with  the  official  men- 
struum, it  does  not  form  a  clear  solution,  but  deposits  more  or  less 
insoluble  matter  (apart  from  the  sugar  of  milk),  and  on  filtration 
yields  a  tincture  that  becomes  turbid  in  time,  and  precipitates  by 
standing.  The  writer  has  examined  a  large  number  of  the  pow- 
dered extracts  of  nux  vomica,  made  by  the  official  process,  by  lead- 
ing manufacturers,  and  in  every  instance  there  has  been  an  odor 
suggestive  of  caramelization  from  overheating,  and  more  or  less 
insoluble  matter  has  been  left  in  using  them  to  make  the  official 
tincture.  Samples  of  the  powdered  extracts  are  submitted  together 
with  samples  of  the  tinctures  made  from  them,  both  before  and 
after  filtration.  The  differences  between  them,  in  physical  properties, 
are  very  apparent. 
