26 
Ehrlich's  Chemotherapy. 
(  Am.  Jour.  Pharm. 
I    January,  1914. 
Therapeutics  is  defined  as  that  branch  of  medical  science  "  which 
deals  with  the  composition,  application,  and  modes  of  operation  of 
the  remedies  for  disease."  But  it  has  now  taken  on  a  somewhat 
broader,  though  less  exact,  meaning,  and  is  understood  to  include 
the  general  administration  of  medicine,  questions  of  hygiene  and 
dietetics,  and  much  that  has  to  do  mainly  with  the  general  well- 
being  of  the  individual.  That  chemistry  must  be,  as  it  has  been  for 
centuries,  inseparable  from  the  study  of  therapeutics  is  obvious, 
and  the  advance  from  the  simplicity  of  the  theory  of  Geber,  accord- 
ing to  which  the  animal  organism  was  made  up  of  only  "  sulphur  " 
and  "  mercury  "  to  our  still  very  imperfect  knowledge  of  the  com- 
plex changes  of  physiological  processes  is,  indeed,  remarkable.  But 
modern  medical  and  chemical  science  is  not  content  with  the  mere 
alleviation  of  the  ravages  of  existing  disease,  that  is,  with  the  modify- 
ing or  assisting  of  functions  temporarily  disturbed,  but  has  struck 
more  directly  at  the  root  of  the  trouble  by  devising  means  actually  to 
destroy  the  causative  agents  and  thus  arrest  the  disease,  or  to  render 
the  animal  organism  inhospitable  to  these  causative  agents,  as,  for 
example,  through  the  anti-toxins  and  the  methods  of  preventive 
medicine  in  general. 
All  this  had  been  done  even  before  the  advent  of  chemotherapy. 
What,  then,  is  new  about  this  combination  of  scientific  effort  in  two  al- 
lied fields  ?  Essentially  this  :  It  is  a  logical,  systematic  campaign  against 
diseases  which  are  caused  by  the  infection  of  the  animal  organism 
by  parasites  (i.e,  bacteria  or  protozoa)  by  means  of  chemicals  which 
have  not  been  found  by  empirical  and  more  or  less  haphazard 
methods,  but  have  been  synthesized  and  built  up  solely  for  the  pur- 
pose in  hand,  and  as  the  result  of  researches  which  have  called  for 
the  highest  type  of  accurate  observation  and  analytical  reasoning 
for  their  execution.  In  this  way  it  has  been  found  possible  to  devise 
means  by  which  the  animal  organism  can  be  sterilized  with  respect 
to  the  parasites  in  question,  and  the  consequent  symptoms  of  disease 
can  be  arrested. 
The  development  of  this  field  is  due  almost  entirely  to  Professor 
Paul  Ehrlich,  of  Frankfort,  and  his  co-workers.  Dr.  Ehrlich  was 
educated  as  a  physician,  but  has  now  become  also  one  of  the  most 
accomplished  and  able  investigators  in  the  field  of  synthetic  organic 
chemistry.  A  conception  of  the  significance  of  his  work  can,  perhaps, 
be  best  obtained  by  noting  important  phases  in  its  progressive  de- 
velopment. 
