540  Assay  Methods  for  Tincture  of  Aconite. {^JSSSl 
our  belief  that  this  concordance  would  be  greater  but  for  certain 
factors  that  were  present  in  the  performance  of  the  cat  method, 
and  which  are  now  the  subject  of  investigation. 
A  comparison  of  the  results  secured  by  the  use  of  the  three  meth- 
ods is  given  in  Table  IV : 
Table  IV. 
Preparation                 M.  L.  D.  Guinea-pigs    L.  D.  Cats         Chemical  Assay- 
Tincture  A   00033  .00041  .04298 
Tincture  B   00065  .00172  .04183 
Tincture  C   00065  .00230  .04183 
Tincture  D   00240  .00388  .04093 
Summary  and  Conclusions. 
1.  Four  samples  of  tincture  of  aconite  secured  from  representa- 
tive manufacturers  showed  little  variation  in  composition  as  deter- 
mined by  the  official  method  of  assay. 
2.  By  tests  of  these  same  samples  upon  guinea-pigs,  great  varia- 
tions in  toxicity  were  apparent. 
3.  The  results  secured  by  the  guinea-pig  test  were  confirmed  by 
the  use  of  Hatcher's  method. 
4.  The  assay  process  demanded  by  the  U.  S.  P.  for  tincture  of 
aconite  is  not  only  useless  but  actually  harmful  in  giving  a  false  sense 
of  security. 
Laboratory  of  Pharmacology, 
Medical  College  of  Virginia, 
Richmond.  Va. 
Bibliography. 
%f.  Am.  Ph.  Assoc.,  ii.  1913,  p.  705. 
2  Chem.  and  Druggist,  1910,  Ixxvii,  p.  892. 
z  Drug  Topics,  New  York,  1909,  xxiv,  p.  340. 
4  Am.  Druggist,  New  York.  1908,  lii,  p.  89. 
6  Arch.  Int.  Med.,  xv,  5.  p.  645. 
6  Proc.  Am.  Pharm.  Assoc.,  lviii,  1910,  p.  820. 
1  Bull.  Pharm.,  191 1,  xxv,  p.  237. 
5  Cushny,  6th  Edition. 
9  Bull.  69,  U.  S.  P.  H.  and  M.  H.  Service  Hvg.  Lab. 
