458 
The  Use  of  Drugs  in  Disease. 
Am.  Jour.  Pharm. 
July,  1920. 
When  animals,  and  even  unicellular  organisms,  are  exposed  to  them 
they  acquire  immunity  to  their  toxic  effects,  to  a  most  extraordinary 
degree.  Prof.  Roger,  in  his  "Medical  Pathology,"  states  that  an 
amoeba  "can  be  gradually  habituated  to  water  containing  2  per 
cent,  of  sea  salt;  it  becomes  so  accustomed  to  the  new  conditions 
that  it  perishes  when  again  brought  back  into  ordinary  water" 
(p.  79).  Parks,  in  his  work  on  "Pathogenic  Bacteria,"  tells  us  that 
bacteria  can  be  habituated  to  carbolic  acid,  if  administered  in  suffi- 
ciently dilute  solutions,  so  that,  in  time,  they  are  able  to  use  it  as 
a  food  (p.  26).  Kobert,  in  his  "Practical  Toxicology,"  says:  "The 
smallest  snail  will  withstand  more  strychnine  than  an  adult  man. 
Many  of  the  stronger  cardiac  poisons  have  no  action  whatever  on 
insects.  The  rabbit  can  take  more  morphine  than  can  a  man  fifty 
times  the  animal's  weight.  Doses  of  lead,  nicotine,  cysticine,  etc., 
sufficient  to  poison  man  fatally  do  not  injure  the  goat.  Amygdalin 
does  not  affect  dogs,  but  it  kills  rabbits.  The  hedge-hog  takes  with 
apparent  enjoyment  a  dose  of  cantharides  that  will  kill  several 
persons  under  excruciating  pains.  Whereas,  the  frog  is  extra- 
ordinarily susceptible  to  the  digitalis  poisons,  they  have  no  affect 
upon  the  toad"  (p.  5).  The  mongoose  is  not  affected  by  a  snake 
bite.  The  California  oil  fly  develops  in  crude  petroleum  oil.  Prof. 
C.  Pichet  has  shown  that  in  such  cases  as  he  has  studied  "The  law 
is  established  that  in  simple  analagous  substances  toxicity  is  increas- 
ingly greater  as  the  substance  considered  is  found  the  less  abundantly 
in  nature"  (Chem.  Abs.,  Feb.  20,  191 1,  p.  714).  Habit  in  the  use 
of  the  poisons,  like  habit  with  arsenic,  alcohol,  morphine,  tobacco, 
etc.,  probably  has  something  to  do  with  such  effects.  The  cells 
are  toned  up  to  a  new  standard.  In  vaccination,  and  serum  treat- 
ment of  disease,  the  stimulation  of  cells  leaves  them  able  to  resist 
greater  amounts  of  the  toxins  of  such  diseases.  The  anaphylactic 
effects  of  different  proteins  and  the  susceptibility  to  most  kinds  of 
diseases  vary  with  experience.  After  one  attack  of  typhoid  fever 
the  second  attack,  if  it  comes  at  all,  is  likely  to  be  very  much  milder. 
The  cells  become  more  resistant.  Prof.  H.  M.  Richards  states  that: 
"It  has  been  established  that  many,  if  not  all,  classes  of  substances 
which  exert  a  toxic  action  on  protoplasm  will  become  stimulating 
ii  presented  to  the  cells  in  sufficiently  small  doses"  {Nature,  March 
24,  1910,  p.  115).  Prof.  Pfeffer,  in  his  "Physiology  of  Plants,"  says: 
"Submaximal  doses  of  many  and  perhaps  all  poisonous  substances 
accelerate  respiration,  growth,  and  the  production  of  heat"  (Vol.  I, 
