DISINFECTANTS  IN  ARRESTING  CATTLE  PLAGUE.  231 
off,  no  further  annoyance  is  felt.  Sweet  oil  rubbed  over  will 
remove  the  last  traces  of  the  acid. 
4.6.  Finding  that  medical  and  scientific  writers  were  unanimous 
in  the  opinion  that  small  internal  doses  of  carbolic  acid  were  at- 
tended with  no  injurious  effect,  I  have  recommended  the  addition 
of  small  quantities  both  to  the  food  and  water  given  to  the  whole 
of  the  stock,  sick  or  healthy,  on  the  farm.  This  has  a  two-fold 
action.  The  water  given  to  cattle  is  seldom  very  pure,  and  car- 
bolic acid  will  neutralize  any  virus  of  infection  which  may  hap- 
pen to  have  found  its  way  into  it.  Moreover,  after  drinking 
aqueous  carbolic  acid,  the  breath  smells  of  it  for  some  hours. 
Now,  it  is  very  probable  that  the  germs,  of  infection  enter  the 
animal  system  through  the  mouth  (17),  and  by  thus  loading  the 
breath  writh  the  antidote,  it  is  reasonable  to  suppose  that  these 
germs  would  be  destroyed  before  they  had  an  opportunity  of 
doing  harm.  The  vapor  of  the  acid,  diffused  through  the  air, 
will  kill  large  insects  ;  it  is  reasonable,  therefore,  to  suppose  that 
it  will  much  more  readily  destroy  microscopic  germs  when 
brought  into  contact  with  its  vapor  during  respiration.  Besides, 
it  is  not  unlikely  that  after  the  system  has  become  habituated  to 
repeated  doses  of  carbolic  acid,  it  will  acquire  additional  power 
of  resisting  the  first  attack  of  disease. 
Since  this  investigation  was  undertaken,  I  have  made  a  col- 
lection of  cases,  illustrating  the  good  effect  of  carbolic  acid  in 
arresting  the  spread  of  the  cattle  plague  in  various  parts  of 
England  and  the  Continent.  I  will  not,  however,  enter  into 
particulars,  but  confine  myself  to  those  cases  which  have  come 
under  my  own  immediate  knowledge.*  I  have  not  yet  met  with 
a  single  instance  in  which  the  plague  has  spread  on  a  farm  where 
this  acid  has  been  freely  used. 
On  the  Adulterations  of  Carbolic  Acid,  and  their  Detection. 
47.  The  official  recommendations  (50)  have  naturally  brought 
*  It  mny,  however,  be  of  interest  to  state  that  carbolic  acid  was  the  princi- 
pal substance  used  in  the  Jardiu  d'Accliinatation,  in  the  Bois  de  Boulogne,  to 
prevent  the  spread  of  the  disease  amongst  the  animals  in  that  establishment. 
According  to  the  Journal  of  the  Society  of  Arts  for  April  13,  1866,  more  than 
twenty  pounds  of  this  acid  were  used  daily,  in  washing  the  walls  and 
mangers,  and  in  sprinkling  the  floors  of  the  stables  and  enclosures,  and  it  is 
to  its  constant  use  that  the  arrest  of  the  malady  is  generally  attributed. 
