Am.  Jour.  Pha^rm.  |  j^p^^  jj^^^^        DiseGSe.  459 
p.  264).  Prof.  Davenport,  Director  of  the  Department  of  Experi- 
mental Evolution,  of  Carnegie  Institute,  reporting  his  many  experi- 
ments with  poisons  on  plants,  says:  "It  is  clear  from  this  table  that 
the  addition  of  even  small  quantities  of  innutritions  and  poisonous 
substances  may  so  affect  the  hylogenic  processes  as  to  cause  twice, 
or  even  far  more  than  twice  the  normal  formation  of  dry  substances 
in  a  given  time,  and  that  this  excessive  growth  increases  with  the 
concentration  of  the  poisonous  substances  up  to  a  certain  optimum 
beyond  which  growth  declines  again  to  below  normal"  {Proceedings 
A.  A.  Advancement  of  Science,  1907,  p.  504). 
Without  the  subtoxic  effects  of  adrenalin  on  the  circulation  the 
arteries  could  not  function  normally  and  without  thyroidine,  growth, 
is  arrested  and  health  seriously  impaired.  Without  hydrochloric  acid 
how  would  gastric  digestion  proceed  ?  In  such  cases  it  is  evident  that 
what  we  call  poisons  have  a  very  important  place  in  physiology.  There 
is  a  universal  law  seen  in  all  living  things.  It  is  the  benefit  derived, 
from  normal  effort,  normal  heat,  normal  electric  currents,  and  normal 
chemical  stimulation.  Within  proper  limits  all  of  these  are  bene- 
ficial. It  is  only  when  their  stimulation  exceeds  such  limits  that 
they  become  harmful  and  this  harmfulness  is  evident  in  all  of  them. 
The  muscles  are  strengthened  by  massage  and  by  effort.  The  skin 
of  hands  and  feet  thicken  with  work.  Heat,  in  proper  amount, 
favors  growth  as  toxic  substances  do.  Just  as  digitalis  strengthens 
the  weakened  heart  so  all  poisons  strengthen  such  parts  of  the 
organism  as  they  act  upon,  provided,  of  course,  that  the  physiological 
maximum  is  not  exceeded.  When  will  the  world  take  to  heart  this 
lesson  and  use  it  for  our  benefit?  When  will  we  all  learn  that  a  sick 
man  is  always  a  poisoned  man?  The  anaphylactic  effects  of  the 
poisons  of  typhoid  give  us  the  clue  to  the  particular  parts  of  the 
system  that  need  toxic  toning  against  such  poisons.  The  anaphy- 
lactic effects  of  malarial  poisons  give  us  a  similar  clue  to  the  parts 
of  the  system  that  require  toning  against  these  poisons.  When 
we  know  enough  to  experimentally  follow  these  clues,  for  all  sorts 
of  diseases  that  we  suffer  from,  and  that  kill  us,  we  will  know  how  to 
do  by  every  one  of  them  as  we  do  now  with  digitalin  in  weakened 
heart.  Such  knowledge  will  put  us  on  the  way  to  true  prophylactic 
medicine. 
To  know  how,  during  threatened  epidemics,  and  at  other 
times,  to  strengthen  every  susceptible  cell  against  that  particular 
kind  of  disease,  will  be  to  enter  into  a  new  era  of  preventive  medicine. 
