6  Pharmacological  Assay  of  Drugs.    {A januaryfim03' 
fern.  Some  experiments  made  to  determine  the  strength  of  pur- 
gatives^gave  no  satisfactory  results,  the  minimal  dose  required  to 
cause  evacuation  of  the  bowels  varying  very  considerably  in  the 
same  animal  and  with  the  same  preparation. 
My  conclusions  in  regard  to  the  pharmacological  assay  are  that  it 
is  a  useful*substitute  for  the  chemical  assay  in  the  case  of  many 
remedies  in  which  the  latter  is  not  applicable,  and  that  it  permits 
of  a  standard  being  formed  for  these  preparations  which  is  suffi- 
ciently constant  and  sufficiently  exact  for  therapeutic  purposes.  It 
is  desirable  that  such  an  assay  should  be  made  in  preparations 
which  fail  to]  effect  the  desired  therapeutic  result  unless  given  in 
quantities  which  act  on  important  organs,  and  which  are  liable  to 
give  rise  to  poisoning  if  unusually  powerful  preparations  are  un- 
knowingly dispensed. 
In  conclusion  it  may  be  mentioned  that  the  pharmacopoeias 
-already  give  the  authority  of  their  imprint  to  the  use  of  pharmaco- 
logical qualitative  tests.  For  in  the  British  pharmacopoeia  one  of 
the  tests  of  atropin  suggested  is  the  dilation  of  the  pupil  induced 
by  its  application,  and  although  no  such  test  is  contained  in  the 
U.S. P.,  yet  the  descriptions  of  drugs  as  bitter  or  sweet  in  taste 
involve  a  pharmacological  experiment  being  performed  upon  the 
pharmacist  himself.  It  seems  more  difficult  to  take  the  next  step — 
the  quantitative  assay — in  the  case  of  the  older  and  more  estab- 
lished remedies  than  in  that  of  newer  discoveries,  for  while  few  of 
the  galenical  preparations  on  the  market  are  thus  assayed  at  present, 
no  one  would  care  to  handle  an  antidiphtheritic  serum  whose 
strength  had  not  been  determined  in  this  way.  The  methods  and 
difficulties  are  the  same  in  each,  or  rather,  the  assay  of  the  galenical 
preparations  may  be  performed  with  less  likelihood  of  error  and 
with  much  greater  precision.  It  may  be  objected  that  animal  ex- 
periment is  absolutely  necessary  in  case  of  the  serum,  for  unless  this 
is  done  there  is  no  method  of  showing  that  an  utterly  worthless 
preparation  of  normal  serum  has  not  been  substituted.  But  the 
same  is  true  in  the  case  of  galenical  preparations ;  for  there  is  no 
question  that  much  of  the  ordinary  fluid  extract  of  ergot  is  utterly 
worthless  and  inert,  and  this  can  be  ascertained  only  by  pharmaco- 
logical assay  at  present.  If  animal  assay  is  necessary  in  the  case  of 
serum  it  is  equally  essential  in  the  case  of  ergot  and  other  vegetable 
drugs.    The  idea  of  animal  experiments  in  assay  is  much  less  foreign 
