DISINFECTANTS  IN  ARRESTING  CATTLE  PLAGUE. 
225 
ON  THE  APPLICATION  OF  DISINFECTANTS  IN  ARREST- 
ING THE  SPREAD  OF  THE  CATTLE  PLAGUE. 
Report  to  Her  Majesty's  Commissioners. 
By  William  Crookes,  F.R.S.  • 
(Continued  from  page  439,  vol.  xxxviii.) 
37.  It  became  now  a  matter  of  considerable  interest  to  ascer- 
tain in  what  way  carbolic  acid  acted  in  arresting  decomposition, 
and  the  following  experiments  were  made,  with  the  object  of 
clearing  up  this  point : — 
XIII.  Albumen  was  mixed  with  four  times  its  bulk  of  water, 
and  a  one  per  cent,  solution  of  pure  carbolic  acid  was  added  to 
it.  No  change  took  place  for  the  first  few  minutes,  but  after  a 
little  time  a  white  cloudiness  was  formed,  which  gradually  col- 
lected together  into  a  coagulum.  On  separating  this,  and 
exposing  it  freely  to  the  air,  it  entirely  resisted  putrefactive 
decomposition.  The  solution  strained  from  the  coagulum  still 
contained  carbolic  acid  and  uncoagulated  albumen. 
XIV.  The  same  experiment  was  repeated  with  pure  cresylic 
acid.  This  acid  has  still  less  affinity  for  albumen,  the  mixed 
solutions  remaining  clear  for  nearly  half-an-hour. 
It  is  evident,  therefore,  that  the  tar  acids  do  not  owe  their 
special  action  to  their  coagulating  powers  on  albumen,  for  the 
last  two  experiments  show,  contrary  to  the  generally  received 
opinion,  that  their  affinity  for  this  body  is  but  slight. 
XV.  A  few  drops  of  carbolic  acid,  added  to  half  a  pint  of 
sugar  syrup  and  yeast  in  full  action,  immediately  put  a  stop  to 
the  fermentation. 
XVI.  Fresh  brewer's  yeast  was  washed  with  the.  solution  of" 
one  per  cent,  of  carbolic  acid,  and  then  with  water.  Its  power 
of  inducing  fermentation  in  a  solution  of  sugar  was  entirely  de- 
stroyed, although  no  perceptible  change  in  the  appearance  of  the 
yeast  cells  could  be  detected  under  the  microscope.  This  expe- 
riment was  repeated  several  times,  and  always  with  the  same 
result,  although  when  the  yeast  was  simply  washed  in  water  it 
readily  induced  fermentation. 
The  odor  of  carbolic  acid  adhered  most  pertinaciously  to  the 
15 
