AmAjr°i;iP896arm'}  Assay  of  Nnx  Vomica.  189 
ASSAY  OF  NUX  VOMICA.- 
By  C.  E.  Smith. 
During  several  years'  experience  in  assaying  this  drug  and  its 
preparations,  a  method  has  gradually  developed,  which  is  believed 
to  have  some  advantages  over  the  others  now  in  use,  so  far  as  the 
writer  is  familiar  with  them.  Its  chief  recommendations  are  that 
accurate  results  can  be  obtained  by  it  without  much  practice,  being 
quite  simple,  and  that  it  requires  no  more  time  and  attention  than 
other  methods,  which  are  expected  to  give  only  approximate 
results. 
The  underlying  principles  made  use  of  are  well  known,  and  have 
been  used  for  similar  purposes  before,  but  the  arrangement  of 
details  is  the  outcome  of  considerable  practice,  and  a  number  of 
changes  were  found  necessary  or  desirable  before  the  process 
assumed  its  present  form,  in  which  it  has  now  given  uniform  satis- 
faction for  nearly  two  years.  In  one  feature  it  is  merely  a  modifi- 
cation of  Keller's  method,  which  apparently  was  not  designed  for 
highly  accurate  work,  but  intended  only  as  a  rough  guide  for  the 
pharmacist. 
The  method  to  be  described  consists  in  exhausting  the  drug  with 
weak  acetic  acid,  evaporating  the  acid  liquid  to  dryness,  dissolving 
the  extract  in  a  very  little  alcohol  and  ammonia,  then  shaking  this 
once  with  a  large  quantity  of  ether  and  chloroform,  and  finally 
titrating  the  separated  alkaloids. 
The  following  are  the  particulars  : 
Place  10  gms.  of  the  powdered  drug  and  100  c.c.  of  10  per  cent,  acetic  acid  into  a 
bottle  provided  with  a  tight  stopper,  and  shake  frequently  during  twelve  hours. 
Filter  the  acid  solution  and  wash  the  residue  on  the  filter  with  cold  water  until 
the  washings  are  tasteless.  Evaporate  the  solution  in  a  shallow  vessel  to  dry- 
ness on  a  water  bath.  While  still  warm,  add  to  the  extract  6  c.c.  of  a  mixture 
consisting  of  equal  volumes  of  strong  alcohol  and  10  per  cent,  ammonia  water, 
and  rub  them  together  by  means  of  a  rubber-tipped  glass  rod,  until  a  uniform 
thick  syrup  results.  Transfer  this  to  a  separator  containing  40  c.c.  of  ether 
and  45  c.c.  of  chloroform.  Wash  the  extract  still  remaining  in  the  evaporating 
dish  into  the  separator  with  6  c.c.  more  of  the  alcohol-ammonia,  applying  it 
in  three  or  four  successive  portions.  Cork  the  separator  and  shake  vigorously 
for  five  minutes,  then  let  it  stand  undisturbed  for  an  hour.  Filter  the  ether- 
chloroform  solution  through  a  small  dry  filter  into  a  flask  of  about  200  c.c. 
capacity,  washing  the  filter  at  the  end  with  ether-chloroform.  Distil  off  the 
solvent  on  a  water  bath,  dissolve  the  alkaloids  in  a  little  alcohol  with  aid  of 
heat,  and  add  a  few  drops  of  methyl-orange  or  hsematoxylin  solution.  Then 
dilute  with  water  and  titrate  with  decinormal  acid. 
