142  Philadelphia  College  of  Pharmacy.      { AmMar°chr' 1910 rm' 
oughly  grounded  in  scientific  investigation,  it  has  been  demonstrated 
in  Philadelphia  that  typhoid  fever  may  be  practically  eliminated 
as  a  serious  disease  of  the  people. 
During  the  interval  between  these  two  discoveries  practically 
all  of  our  knowledge  on  this  interesting  subject  has  evolved,  and 
it  may  be  stated  that  the  most  important  of  our  knowledge  con- 
cerning prevention  began  with  the  discovery  of  the  cause  of  the 
disease  by  Eberth  in  the  year  1880.  Following  Eberth's  discovery 
the  great  difficulty  that  was  encountered  was  in  the  identification 
of  the  organisms  that  he  claimed  to  be  specifically  answerable  for 
typhoid  fever,  and  this  difficulty  was  not  by  any  means  lessened 
through  the  subsequent  discovery  of  an  organism  in  the  intestinal 
canal  that  is  in  many  particulars  so  like  the  typhoid  germ  as  to 
make  their  separation  more  or  less  uncertain  with  the  methods 
available  at  that  time.  This  organism,  the  colon  bacillus,  has  nothing 
to  do,  in  so  far  as  is  known,  with  typhoid  fever.  It  was  pointed 
out  that  while  these  two  organisms  are  not  identical,  yet  botanically 
they  have  a  close  relation,  and  more  recent  studies  have  shown 
that  there  are  thirty  or  forty  organisms  belonging  to  the  typhoid- 
colon  group  which  have  been  modified  by  their  environment,  as 
in  the  body  of  man,  in  culture  media,  and  elsewhere.  Dr.  Abbott 
stated  that  no  one,  however  skilled  he  may  be,  can  identify  the 
typhoid  bacillus  by  means  of  the  microscope  alone,  it  being  a 
simple  rod-shaped  organism  like  others  of  the  group.  The  various 
attempts  made  with  the  object  of  devising  methods  for  differen- 
tiating the  Bacillus  typhosus  were  described.  Of  these  the  agglu- 
tination test,  which  is  based  upon  the  condition  that  when  an 
individual  suffers  from  an  infectious  disease  he  becomes  more 
or  less  immune  to  it,  is  the  most  reliable.  Thus,  if  a  beef-tea 
culture  of  typhoid  bacilli,  in  which  the  organisms  are  in  a  motile 
condition,  be  added  to  the  blood-serum  of  a  person  who  has, 
or  has  had,  typhoid  fever,  the  organisms  become  immotile  and 
massed  together, — agglutinated, — while  with  a  similar  culture  of 
the  colon  organism  no  such  effect  is  produced.  Dr.  Abbott  said  that 
in  the  treatment  of  typhoid  fever  it  is  not  possible  to  employ  an  anti- 
toxic serum  for  the  reason  that  the  toxin  is  endotoxic,  that  is,  closely 
bound  up  with  the  protoplasm  of  the  cell  (organism),  and  is  only 
liberated  when  the  latter  is  broken  down,  as  in  the  digestion  of  the 
organisms  by  the  leucocytes. 
Then  coming  to  the  more  practical  side  of  the  subject,  Dr. 
