198  Use  of  Antitoxins  and  Vaccines.       { Xmw™\$u&rrn' 
Since  the  losses  involved  in  the  manufacture  of  these  products 
must  vary  with  the  mechanical  details,  a  brief  description  of  the 
mechanical  conditions  employed  will  suffice.  The  compressed  tablets 
were  usually  made  in  unit  runs  of  50,000  and  the  calculated  strength 
in  the  table  was  found  by  taking  into  account  both  the  waste,  which 
was  in  each  case  weighed,  and  also  the  over  or  under  run  in  number. 
The  moulded  tablets  were  made  in  unit  batches  of  15,000  and  dried 
artificially  in  45  to  60  minutes.  All  the  calculations  of  loss  are  based 
on  the  colorimetric  determinations. 
Contribution  from  the  Chemical  Research 
Laboratory  of  The  Upjohn  Company. 
Kalamazoo,  Mich.,  March,  1914. 
THEORIES  UNDERLYING  THE  USE  OF  ANTITOXINS 
AND  VACCINES.* 
By  A.  Parker  Hitchens,  M.D.,  Glenolden,  Pa. 
The  action  of  antitoxins  has  so  definitely  passed  beyond  the 
stage  of  pure  speculation  that  I  think  there  will  be  little  difficulty  in 
expounding  the  theories  underlying  their  use.  With  regard  to 
vaccines  likewise  we  have  come  to  understand  more  clearly  their 
mode  of  action  without  the  use  of  a  terminology  recognized  only  by 
the  initiated  few. 
Out  of  studies  in  immunology — the  science  dealing  with  the 
mechanism  of  contagious  diseasea — have  developed  methods  by 
which  the  body  may  be  assisted  either  to  prevent  disease-producing 
germs  from  gaining  a  foothold,  or  to  eliminate  them  after  they 
have  become  established.  • 
The  disease-producing  bacteria  are  classified  in  various  ways, 
according  to  their  functions.  For  our  present  purpose,  the  classifica- 
tion of  most  interest  is  that  which  considers  the  bacteria  according 
to  their  manner  of  causing  disease.  Thus  we  find  that  one  group 
of  bacteria  produces  definite,  soluble,  and  diffusible  poisons,  and 
that  all  the  symptoms  of  the  disease  are  directly  or  indirectly  de- 
pendent on  the  action  of  these  poisons  upon  the  tissues  for  which 
they  have  an  affinity.  The  second  group  of  bacteria,  on  the  con- 
trary, does  not  produce  soluble  and  diffusible  toxins  in  appreciable 
*  Read  at  a  meeting  of  the  American  Pharmaceutical  Association,  Phila- 
delphia Branch,  April  7,  1914. 
