578  Standardization  of  Piscidia  erythrina.  {Am*s\°pY\9i9rm° 
forcing  the  thumb  and  index  finger  of  the  left  hand  between  the 
jaws,  neck  and  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. 
Actual  Standardisation. — Administer  to  a  series  of  three  selected 
dogs  9/10,  10/10  and  11/10  of  the  standard  dose  of  the  preparation 
to  be  tested,  for  each  kilo  body  weight  of  animal.  The  animals  are 
then  placed  in  a  room  where  they  will  be  undisturbed  and  are  remote 
from  noise  and  excitement ;  careful  observation  should  be  made  and 
the  results  recorded  during  four  or  five  hours. 
If  this  preliminary  test  shows  that  the  drug  is  either  above  or 
below  standard  strength  other  dogs  are  given  progressively  increas- 
ing or  decreasing  doses,  as  the  case  may  be,  until  the  smallest  dose 
per  kilo  body  weight  is  found  which  will  produce  an  action  just  suffi- 
ciently pronounced  to  bring  on  the  stage  of  incoordination.  This 
is  distinguished  by  a  slight  ataxia  when  walking  and  a  drooping  of 
the  head  and  gentle  swaying  of  the  body  while  at  rest.  The  relative 
strength  of  the  preparation  tested  is  then  computed  between  the 
"  minimum  dose "  and  the  "  standard  minimum  dose "  by  simple 
proportion. 
The  personal  equation  plays  an  important  part  in  this  assay  just 
as  in  cannabis,  since  the  accuracy  of  the  test  depends  largely  upon 
the  experience  of  the  operator  and  his  ability  in  determining  just 
when  the  effects  of  the  drug  manifest  themselves.  In  the  hands  of 
an  experienced  operator,  therefore,  results  may  be  obtained  which 
will  show,  with  fair  accuracy,  the  relative  value  of  any  preparation 
of  Jamaica  dogwood. 
Tentative  Standard. 
In  order  to  determine  the  average  amount  of  the  drug  per  kilo 
required  to  produce  incoordination  in  dogs  and  to  set  a  tentative 
standard  for  assay  purposes,  ten  different  samples  of  fluid  extract 
obtained  from  the  various  pharmaceutical  manufacturing  houses  in 
the  United  States  were  assayed  by  the  above  method  and  were  found 
to  produce  incoordination  in  dogs  in  the  following  doses : 
