AmNovr'i92iarm' \  V<due  of  Drugs  in  Internal  Medicine.  763 
Through  chemical,  physiologic,  psychologic,  pathologic  and 
clinical  studies  we  have  learned  much  regarding  pathogenesis,  that  is 
to  say  regarding  the  chains  of  changes  in  the  body  that  follow  on 
injuries  of  various  sorts.  Synthetic  chemistry  has  supplied  us  with 
a  host  of  new  substances  for  trial  as  remedies.  The  new  sciences  of 
pharmacology  and  toxicology  have  revealed  to  us  the  mode  of  action 
of  drugs  and  poisons,  and  medical  students  are  observing  for  them- 
selves, in  our  pharmacologic  laboratories,  the  physiologic  effects  that 
follow  the  introduction  of  foreign  substances  into  the  animal  body, 
and  they  measure  some  of  these  effects  with  instruments  of  pre- 
cision. Knowing  only  too  well  that,  in  the  diseased  body,  drugs 
often  act  in  an  unexpected  manner,  in  ways  very  different  from 
those  in  which  they  act  in  the  healthy  body,  clinicians  have  wisely 
seen  that  the  pharmacology  of  the  laboratory,  though  of  great  value 
for  the  general  advance  of  scientific  therapy,  cannot  take  the  place 
of  accurate  clinical  observation.  It  can  do  much  to  guide  therapeutic 
effort  and  to  supply  criteria  for  judging  of  its  effects,  but  the  final 
and  crucial  test  of  the  value  of  any  therapy  is  that  of  actual  clinical 
experience.  The  clinic  can  help  the  laboratory,  and  the  laboratory 
the  clinic ;  but  each  has  its  independent  domain  that  should  be  con- 
scientiously worked  and  zealously  safeguarded. 
THE  NEW  EXPERIMENTAL  SCIENCES. 
Recently,  laudable  attempts  partially  to  bridge  the  gap  between 
the  pharmacologic  laboratory  and  the  clinic,  in  the  interests  of  phar- 
macotherapy, have  been  observable  in  the  work  of  the  new  sciences 
of  experimental  pathology  and  experimental  therapy,  especially  ex- 
perimental substitution  therapy,  and  experimental  antiparasitic  ther- 
apy (immunotherapy,  serotherapy  and  chemotherapy). 
Workers  in  these  new  sciences  reproduce  certain  sharply  cir- 
cumscribed syndromes  in  experimental  animals  and  then  study  vari- 
ous forms  of  treatment  experimentally,  analyzing  the  effectsxof  the 
measures  tried.  With  the  advent  of  experimental  pathology  and 
experimental  therapy,  we  can  hope  for  the  rapid  development  of  a 
systematic  science  of  therapy ;  and  though  the  transfer  of  results  of 
experiments  in  treatment  of  sick  animals  to  treatment  of  the  sick 
human  being  will  always  mean  a  leap  from  the  known  to  the  un- 
known, still  this  transit  will  from  now  on  be  made  with  ever  lessened 
danger.    New  drugs  and  chemicals  will  in  the  future  be  thoroughly 
