Am.  jour.  Pharm.  |    Pharmacoloqy  and  Therap eutics :  cai 
November,  191 7.  ■>  ^ J  £  Jta 
plates  with  scientific  skepticism  that  which  is  unproved,  and  he  pro- 
ceeds slowly  and  carefully  from  the  known  to  the  unknown.  The 
therapeutist,  on  the  other  hand,  brought  face  to  face  with  a  crisis 
in  the  life  of  his  patient,  cannot  refuse  to  try  the  unproved  when 
remedies  of  known  efficacy  are  lacking.  Hence  he  often  grasps  at 
straws,  being  restrained  only  by  the  possibility  of  doing  harm  to  his 
patient.  Such  a  practice,  justifiable  in  itself,  too  often  leads  to  those 
habits  of  inaccurate  reasoning  that  are  reflected  in  therapeutic  litera- 
ture. Optimism  in  practice  often  means  an  unjustified  and  uncrit- 
ical enthusiasm  in  the  interpretation  of  results. 
The  pharmacologist  and  the  therapeutist  are  further  separated 
by  the  conditions  under  which  their  observations  are  commonly 
made.  In  the  laboratory  the  action  of  drugs  is  usually  studied  on 
normal  animals,  and  toxic  doses  can  be  administered  with  impunity. 
In  the  clinic,  on  the  other  hand,  therapeutic  doses  alone  are  used, 
and  the  effects  of  these  are  often  modified  by  disease.  The  pharma- 
cologist is  permitted  to  employ  methods  of  study  which  involve 
operative  or  other  Ifarmful  procedures.  The  clinician  is  restricted 
to  those  methods  of  study  that  can  be  used  without  harm  to  his 
patient.  Finally,  the  laboratory  worker  plans  a  series  of  experi- 
ments, and  he  endeavors  to  eliminate  errors  by  repetition  and  by 
controlling  the  various  factors  that  might  influence  his  results.  In 
therapeutics  the  number  of  observations  is  necessarily  limited  by 
the  available  clinical  material,  and  the  interpretation  of  results  is 
often  hampered  by  the  fact  that  the  effects  of  other  factors,  such  as 
the  natural  course  of  the  disease  and  the  action  of  the  other  drugs 
used,  is  difficult  to  estimate  and  is,  indeed,  often  estimated  incor- 
rectly. Under  such  conditions,  years  may  elapse  before  even  a 
simple  therapeutic  problem  is  conclusively  answered. 
As  I  have  said,  pharmacologic  studies  are  usually  made  on 
normal  animals.  In  seeking  to  utilize  the  knowledge  thus  obtained 
for  therapeutic  purposes,  the  following  questions  arise:  (i)  Are 
the  effects  observed  produced  by  doses  that  can  safely  and  easily 
be  administered  to  patients?  (2)  Will  the  human  organism  react  in 
the  same  manner  as  the  animal  studied?  (3)  How  is  this  reaction 
modified  by  disease  ? 
The  question  of  dosage,  simple  as  it  may  seem,  has  caused  and 
will  probably  continue  to  cause  occasional  therapeutic  stumbles.  The 
fact  that  large  doses  of  strychnine  were  known  to  produce  a  marked 
rise  of  arterial  pressure  in  animal  experiments  was  in  part  respon- 
