DISINFECTANTS  IN  ARRESTING  CATTLE  PLAGUE. 
431 
make  the  walls  of  the  building  permanently  damp,  and  fitted  to 
foster  the  vitality  of  virus-cells,  should  they  fall  upon  them. 
27.  A  plan  of  fumigation  by  chlorine  has  recently  been 
recommended  which  appears  to  possess  another  disadvantage. 
It  is  based  upon  the  decomposition  of  chlorate  of  potash  by 
hydrochloric  acid.  This  reaction  does  not  evolve  pure  chlorine, 
but  a  gas  called  euchlorine  (supposed  to  be  a  mixture  of  chlorine 
and  chloric  oxide.)  The  properties  of  this  gas  are  different 
from  those  of  chlorine,  and  nothing  is  known  about  its  special 
value  as  a  disinfectant.  It  is  dangerously  explosive,  the  act  of 
transferring  it  from  one  vessel  to  another,  or  even  the  warmth  of 
the  hand,  being  sometimes  sufficient  to  shatter  the  vessel  to 
pieces  with  a  loud  report. 
28.  If  commercial  chloride  of  lime  is  used  as  the  source  of 
chlorine,  there  is  the  additional  disadvantage  that  the  compound 
into  which  it  changes — chloride  of  calcium — is,  as  before  men- 
tioned, (21,  26),  very  deliquescent,  and  will  leave  the  floors,  walls, 
and  especially  the  wood-work  washed  with  it,  permanently  damp  ; 
whilst,  if  thrown  in  the  solid  state  on  the  floor,  it  rapidly 
attracts  moisture,  and  becomes  unpleasantly  wet.  It  also  com- 
municates a  disagreeable  odor  to  the  hands  when  it  is  touched. 
It  is  one  of  the  things  most  easily  adulterated,  and  it  would  be 
scarcely  possible  to  supply  an  ordinary  consumer  with  a  test  by 
which  he  could  ascertain  its  strength  and  purity. 
29.  Ozone. — This  powerful  agent  attacks  all  kinds  of  organic 
matter  with  intense  energy.  But  as  in  the  case  of  chlorine,  the 
specific  substance  which  we  most  want  to  destroy  would  be  nearly 
the  last  to  go  ;  and,  as  it  would  be  almost  impossible  to  generate 
ozone  in  quantity  in  an  infected  shed,  its  energies  would  in  most 
cases  be  spent  in  doing  useless  work.  When  much  ozone  is 
present  in  the  air  it  acts  hurtfully  on  the  respiratory  organs. 
Owing  to  the  extremely  poisonous  nature  of  phosphorus,  and 
its  ready  inflammability,  danger  would  arise  from  the  production 
of  ozone  by  the  slow  combustion  of  this  element.  In  the  hands 
of  ordinarv  farm  servants  serious  accidents  from  fire  would  be 
constantly  occurring. 
Antiseptics. 
30.  Oxidizing  disinfectants  produce  their  effect  by  actually 
