204 
Standard  Tincture  of  Nux  Vomica. 
J  Am.  Jour.  Pharni. 
t       April,  1884. 
in  a  given  volume  of  alcohol.  We  propose  that  the  standard  tincture 
of  nux  vomica  shall  contain  0*24  per  cent,  of  total  alkaloid,  that  is  1 
grain  of  total  alkaloid  in  1  fluid  ounce  of  tincture.  This  proposal 
results  from  a  comparison  of  the  analyses  which  we  have  already  pub- 
lished of  the  various  tinctures  of  nux  vomica  now  being  used  in  medi- 
cine, and  represents  the  alkaloidal  content  of  a  good  commercial  speci- 
men. The  mode  of  preparing  the  standard  tincture  by  the  first  method 
is  simple  in  procedure  and  eminently  satisfactory  in  result.  An  experi- 
ment was  made  by  taking  that  volume  of  the  strong  percolate,  assayed 
as  before  described,  which  contained  20  grains  of  total  alkaloid,  this 
was  diluted  to  one  pint  with  alcohol  (100:25).  A  pale  yellow  per- 
fectly clear  tincture  was  obtained,  every  ounce  of  which  contained  1 
grain  of  total  alkaloid.  This  tincture  did  not  deposit  or  otherwise 
change  after  being  kept  for  one  month.  A  practical  objection  perhaps 
attaches  to  this  method,  as  one  for  general  use,  which  must  be  allowed 
to  have  some  weight.  It  involves  the  preparation  of  two  tinctures  of 
nux  vomica,  the  one  strong,  the  other  weak,  aud  the  substitution  of 
the  one  for  the  other  in  dispensing  would  be  attended  with  grave 
results ;  this  perhaps  is  an  objection  to  recommending  the  process  for 
general  use,  although  it  is  a  point  on  which  Ave  speak  with  some 
reserve.  A  number  of  experiments  were  then  made  in  connection 
with  the  second  method.  It  has  been  already  shown  that  with  ordi- 
nary extract  of  nux  vomica  there  is  no  very  easy  method  of  obtaining 
a  solution  in  alcohol  which  is  at  once  perfect  and  permanent  (Pharm. 
Jour.  [3],  xiv.,  442).  But  it  now  seemed  probable,  having  prepared 
an  extract  by  exhausting  the  nux  vomica  with  alcohol  of  definite 
strength  and  evaporating  on  a  water-bath,  that  such  an  extract  would 
redissolve  in  alcohol  of  the  same  strength  that  had  been  used  in  its 
production.  One  gram  of  the  standard  extract  of  nux  vomica,  con- 
taining 15  per  cent,  of  total  alkaloid,  was  mixed  with  60  cubic  centi- 
metres of  alcohol  (100  :  25).  By  stirring  the  Avhole  of  the  extract  was 
dissolved,  and  the  perfectly  clear  tincture  deposited  a  very  small 
quantity  of  a  white  sediment  after  one  month.1  Some  of  the  sediment 
was  examined  and  contained  no  alkaloid.  Thus  a  standard  tincture  of 
nux  vomica  could  also  be  readily  prepared  by  the  solution  of  the 
standard  extract  in  alcohol  of  certain  strength.  The  tincture  prepared 
as  above  detailed  should  contain  0*24  per  cent,  of  total  alkaloid  and  to 
confirm  this  the  tincture  was  assayed  and  yielded  0"2402  per  cent,  of 
1  The  extract,  it  should  be  noted,  will  not  wholly  dissolve  in  rectified 
spirit 
