DISINFECTANTS  IN  ARRESTING  CATTLE  PLAGUE. 
229 
tation  that  some  of  the  virus  cells,  supposed  to  be  floating  about 
in  the  atmosphere,  would  be  arrested  by  the  wool. 
The  suction  was  continued  for  ten  minutes.  One  piece  of  the 
infected  wool  was  then  exposed  for  half  an  hour  to  the  vapor 
of  carbolic  acid.  Two  apparently  healthy  calves  were  selected, 
and  an  incision  being  made  beneath  the  skin,  these  pieces  of 
wool  were  respectively  inserted  in  each.  The  animal  thus  in- 
oculated with  the  infected  wool,  which  had  been  exposed  to  car- 
bolic acid,  remained  perfectly  well,  but  the  other  animal  took 
the  disease,  and  died  in  a  few  days. 
I  place  this  upon  record,  although  I  do  not  attach  much  im- 
portance to  it,  as  the  experiment  was  made  at  a  farm  where  the 
plague  was  raging ;  and  it  is  quite  possible  that  the  calf  which 
died  did  not  take  the  disease  from  the  wool.  Unfortunately, 
time  would  not  permit  me  to  verify  this  experiment  so  as  to 
place  its  results  beyond  doubt.  It  is  likewise  desirable  to  inocu- 
late with  the  virus  itself,  collected  from  the  eyes,  &C,  of  diseased 
animals,  mixed  with  different  quantities  of  carbolic  acid.  There 
can  be  but  little  doubt  that  the  issue  would  prove  satisfactory. 
44.  I  first  employed  carbolic  acid  on  a  large  scale  early  in 
December  last.  Considerable  experience  suggested  to  me  the 
best  way  of  proceeding,  and  I  consider  that  the  results  have 
proved  that  my  views  were  correct.  A  detailed  account  of  the 
various  experiments  is  given  in  the  next  part. 
I  had  two  objects  in  view ;  firstly,  to  apply  the  energetic  dis- 
infecting powers  of  sulphurous  acid  for  the  purpose  of  purifying 
the  cattle  sheds  two  or  three  times  a  week ;  and  secondly,  to 
trust  to  carbolic  acid  as  a  permanent  means  of  protecting  the 
animals  from  extraneous  infection.  Sulphur  fumigation  and 
carbolic  acid  agree  very  well  together,  and  somewhat  assist  each 
other's  action  ;  whereas  oxidizing  disinfectants,  used  either  with 
carbolic  acid  or  sulphurous  acid,  are  inoperative  ;  the  energies 
which  should  be  directed  to  the  destruction  of  infection  being 
exhausted  in  neutralizing  each  other.  When  dealing  with  such 
an  overwhelming  amount  of  putrefying  and  putrescible  organic 
matter  as  is  met  with  in  a  farm-yard,  it  is  of  paramount  import- 
ance to  economize  as  much  as  possible  the  disinfectant.  I  have 
already  shown  that  chlorine  and  ozone  are  very  wasteful  agents. 
