Eighteen  hogs  were  vaccinated  by  the  serum-simultaneous  method,
serum  in  doses  of  5  c.  c,  10  c.  c,  15  c.  c,  and  20  c.  c.  being  used  in  con-
junction with  2  c.  c.  of  disease-producing  blood.  Of  these  18  hogs  2
became  sick;  none  died.
Four  hogs  were  injected  with  disease-producing  blood  alone;  aU
became  sick;  3  died,  and  1  was  killed  when  in  a  moribund  condition.
Eight  hogs  were  injected  wath  serum  alone  and  all  remained  well.
Only  6  of  the  vaccinated  hogs  were  later  exposed  to  infection;  1  of
these  died,  but  without  exhibiting  either  before  death  or  at  autopsy
positive  signs  of  hog  cholera.  Of  3  pen  checks  which  were  exposed  at
the  same  time  as  the  6  vaccinated  hogs,  1  died  of  hog  cholera,  the
other  became  sick  but  recovered,  while  the  third  check  did  not  become
plainly  ill.
As  a  result  of  the  experiments  with  the  first  drawing  of  serum  from
hog  1274,  we  may  conclude  that —

(1)  The  serum  when  given  in  sufficient  dose  will  protect  non-
immunes from  a  simultaneous  injection  of  a  fatal  dose  of  disease-
producing  blood.
(2)  The  serum-simultaneous  injections  in  which  the  largest  dose  of
hyperimmune  serum  was  used  seemed  to  afford  quite  as  com})lete
protection  from  hog  cholera  when  exposure  took  place  three  weeks
after  vaccination  as  was  afforded  by  the  injection  of  disease-producing
blood  with  a  smaller  dose  of  serum.
(3)  An  insufficient  dose  of  serum  with  disease-producing  blood  ap-
peared to  result  in  more  or  less  permanent  injury  to  tlie  hogs  treated
in  that  manner.
Seri'm  from  Immune  1297  {Si,o\v  Method).
Experiment  XV. —  First  drnirimj  of  nerum.
