362 
DISINFECTANTS  IN  ARRESTING  CATTLE  PLAGUE. 
dice,  by  destroying  the  foul  odors  which  are  the  usual  accompani- 
ments of  infection,  whilst,  antiseptics  have  little  or  no  action  on 
these  gases.  I  hope  to  succeed  in  showing  that  this  fallacious 
mode  of  estimating  the  relative  value  of  disinfectants  and 
antiseptics,  is  one  which  does  great  injustice  to  the  latter. 
15.  Cleanliness,  ventillation,  and  good  drainage  have  been 
spoken  of  as  comprising  all  that  is  required  to  preserve  cattle 
from  the  plague.  This  is  not  correct.  Due  attention  to  these 
points  will  certainly  tend  to  preserve  the  animals  in  better 
health,  and  will  render  them  more  fitted  to  sustain  the  exhaust- 
ing action  of  the  disease ;  but  ventillation,  cleanliness,  and 
drainage  are  unavailing  against  the  importation  of  the  germs  of 
disease  from  adjacent  herds.  These  measures  are  of  value  as 
they  remove  what  might  otherwise  become  nurseries  for  infec- 
tion. A  germ  from  without,  falling  on  to  a  clean  dry  stall,  is 
likely  soon  to  die  ;  but  if  it  meet  with  moisture  and  dirt,  its 
vitality  may  be  fostered,  and  the  chance  of  its  coming  into  con- 
tact with  a  healthy  animal  so  much  the  more  increased  (10.) 
Cleanliness,  drainage,  and  ventillation  are  admirable  adjuncts  to 
disinfection,  but  it  is  not  safe  to  trust  to  them  alone  to  ward  off 
the  plague.  Ventillation,  by  allowing  a  greater  number  of  cubic 
feet  of  air  per  minute  to  pass  over  the  animals,  may  be,  in  fact, 
the  means  of  conveying  the  infection  to  them.  A  moderately 
ventillated  shed,  in  which  antiseptics  are  yfreely  employed,  has 
been  proved  to  be  a  place  far  safer  for  cattle  than  an  open  field  ; 
although  when  the  animals  have  caught  the  disease  the  mortality 
appears  to  be  less  when  they  are  turned  out  into  an  open  field 
than  when  they  are  kept  in  sheds. 
16.  Dr.  Angus  Smith,  by  his  exhaustive  examination  of  dis- 
infectants, has  rendered  it  unnecessary  for  me  to  search  amongst 
the  numerous  classes  of  possibly  useful  bodies  for  those  likely  to 
be  of  practical  value.  His  results  I  accept  in  the  full  conviction 
that  they  are  correct ;  and  I  proceed  to  investigate  the  respec- 
tive merits  of  the  comparatively  small  number  of  agents  available 
for  disinfection. 
17.  At  the  outset  it  is  necessary  to  strike  off  at  once  a  whole 
class  of  valuable  agents  which  will  not  meet  the  requirements  of 
the  case.    It  appears  to  have  been  satisfactorily  proved  that  the 
