334 
Notes  on  "Physiological  Testing."  {AmjJuoi^iF0h8arm' 
showed  that  by  gastric  digestion  digitalin  underwent  a  marked  weak- 
ening,  so  that  it  can  be  easily  seen  that  the  responsibility  for  a  failure 
of  digitalis  to  act  clinically  cannot  always  be  laid  at  the  pharma- 
cist's door  and  this  is  well  worth  remembering  in  these  days  of  law- 
suits. 
Certain  of  the  purgative  drugs  likewise  cannot  be  satisfactorily 
standardized  by  chemical  means,  and  the  physiological  test  is  also 
rather  unsatisfactory,  but  it  is  better  than  the  chemical.  The  emetic 
drugs  can  be  assayed  chemically,  but  can  also  be  tested  physiologi- 
cally on  dogs. 
These  tests  give  no  indication  of  the  activity  of  the  drug  on  man, 
as  various  animals  respond  differently,  but  only  as  to  its  comparative 
strength. 
Such,  in  brief,  are  the  methods  in  use  in  the  testing  of  galenical 
preparations,  and  as  quantitative  procedures  much  is  to  be  desired. 
It  must  be  remembered  that  because  one  firm  calls  a  drug  physio- 
logically tested,  it  does  not  follow  that  the  drug  compares  at  all  with 
another  so-called  physiologically  tested  preparation.  In  fact,  the 
standards  and  ideas  of  testing  of  one  firm  may  be  very  different  from 
that  of  another,  and  no  label  "  physiolocically  tested"  means  much 
unless  one  knows  the  standard  used.  One  English  firm  is  putting 
out  digitalis  leaves  and  specifies  them  to  be  standardized  on  a  basis  of 
1*4  grammes  of  the  leaf  as  the  minimal  toxic  dose  for  iOO-gramme 
frog.    Our  American  firms  simply  state  "  physiologically  tested." 
While  many  of  these  preparations  may  contain  full  alkaloidal 
strength,  which  can  be  determined  by  chemical  analysis,  yet  it  is 
perfectly  possible  that  some  may  be  too  irritating  for  certain  usage 
and  set  up  purgation  or  emesis.  As  is  well  known,  one  of  the  prob- 
lems has  been  to  obtain  a  digitalis  preparation  which  is  non-irritating. 
This  irritating  action  can  be  determined  by  the  biological  test,  such 
as  described  by  Houghton.1  Again,  the  simple  determination  of  the 
amount  of  alkaloids  present  in  such  preparations  does  not  neces- 
sarily correspond  to  the  activity  of  the  preparation ;  because,  as 
physical  chemistry  has  shown,  the  presence  of  a  large  amount  of 
colloids  often  interferes  with  the  full  action  of  certain  chemical  com. 
pounds.    Again,  the  presence  of  certain  elements  increases  the 
1  Houghton,  E.  M,  Attempt  to  Obtain  a  Uniformly  Active,  Sterile  and  Non- 
irritating  Preparation  of  Digitalis.    Medicine,  Vol.  9,  p.  982.  1903. 
