^Sp/ember^^92o: }  United  States  Pharmacopoeial  Revision.  643 
laboratories,  and  therefore  do  not  show  as  well  as  they  might,  the 
degree  of  efficiency  to  which  biologic  assays  have  been  developed. 
Due  to  this  fact,  very  little  attention  has  been  paid  to  the  methods 
as  set  forth  in  the  U.  S.  P.  IX,  as  all  evidence  tends  to  prove  that 
they  are  less  accurate  and  reliable  than  the  methods  in  common  use. 
In  the  second  paragraph  of  the  chapter  on  "Biologic  Assays" 
in  the  U.  S.  Pharmacopoeia,  the  following  statement  appears: 
"Brief  descriptions  of  the  more  commonly  accepted  methods 
are  given  here  in  order,  first,  to  direct  the  attention  of  manufacturers 
to  them ;  second,  to  ascertain  the  points  of  weakness  which  may  exist 
in  them;  and,  finally,  to  outline  methods  and  establish  standards 
which  those  interested  may  adopt  should  they  desire  to  assay  their 
products  and  have  them  conform  to  the  standards  proposed." 
For  the  reasons  stated  above,  remarks  are  mostly  limited  to 
what  we  consider  "points  of  weakness"  which  exist  in  the  present 
U.  S.  P.  methods. 
Cannabis,  page  60^. — "Before  administration  the  animal  should 
not  be  fed  for  twenty-four  hours  in  order  to  hasten  absorption." 
It  is  not  necessary  to  withhold  food  for  more  than  ten  to  twelve 
hours  before  making  a  test,  as  the  stomach  will  be  completely  emptied 
in  this  time  and  it  will  not  be  so  hard  on  the  animal. 
"The  head  of  the  animal  being  held,  its  mouth  is  opened  and  the 
capsule  or  pill  is  placed  upon  the  back  of  the  tongue.  Usually  the 
drug  is  easily  swallowed  when  given  in  this  way,  but  this  may  be 
facilitated  by  giving  the  animal  a  small  amount  of  water  to  drink." 
This  method  works  sometimes,  but  as  a  general  rule  the  dog  does 
not  feel  inclined  to  take  the  capsule  so  easily.  In  practical  work 
it  will  be  found  that  it  is  almost  impossible  to  make  the  dog  swallow 
a  capsule  by  the  above  method.  Pulling  the  tongue  well  forward, 
placing  the  capsule  far  on  the  back  of  it  and  then  releasing  the  tongue, 
is  an  improvement,  but  the  best  method  is  the  following: 
"Open  the  animal's  mouth  by  forcing  the  thumb  and  index 
finger  of  the  left  hand  between  the  jaws,  back  of  the  teeth.  The 
capsule  is  then  placed  on  the  back  of  the  tongue  with  the  right  hand 
and  the  mouth  quickly  closed;  while  still  holding  the  mouth  shut, 
the  animal  can  be  made  to  swallow  the  capsule  immediately  by 
slapping  it  on  the  throat."^ 
By  this  method  the  most  obstinate  dog  can  be  made  to  swallow 
the  capsule  on  the  first  attempt. 
^  Pittenger:  "Biochemic  Drug  Assay  Methods,"  page  loi. 
