226         DISINFECTANTS  IN  ARRESTING  CATTLE  PLAGUE. 
yeast,  and  by  no  ordinary  amount  of  washing  and  exposure  to 
the  air  could  it  be  removed. 
XVII.  Strychnine  was  added  to  a  mixture  of  yeast  and  sugar 
solution  in  full  fermentation.  No  visible  effect  was  produced, 
the  evolution  of  carbonic  acid  continuing  as  brisk  as  before. 
The  above  experiments,  some  of  which  were  performed  by  my 
friend  Mr.  Spiller,  prove  conclusively  that  carbolic  acid  has  a 
special  action  on  the  fermentation  induced  by  organized  matter ; 
it  not  only  arrests  it  instantly  when  in  progress,  but  it  prevents 
the  development  of  future  fermentation. 
38.  The  action  of  the  tar  acids  was  now  examined  on  certain 
chemical  bodies,  which  are  supposed  to  act  by  fermentation,  in 
order  to  see  if  they  were  influenced  in  the  same  manner. 
XVIII.  A  solution  of  diastase  (infusion  of  malt)  was  mixed 
with  thick  starch  paste,  and  a  one  per  cent,  solution  of  carbolic 
acid.  On  gently  heating  for  a  short  time,  the  starch  was  con- 
verted into  dextrine,  as  completely  as  if  no  carbolic  acid  had 
been  present. 
XIX.  Amygdalin  was  mixed  with  synaptase  (emulsion  of 
sweet  almonds)  in  the  presence  of  carbolic  acid.  The  formation 
of  the  essential  oil  took  place  with  apparently  the  same  readi- 
ness as  if  carbolic  acid  had  been  absent.* 
The  foregoing  results  show  that  carbolic  acid  has  no  action  on 
purely  chemical  ferments.  These  consist  of  definite  nitrogenous 
compounds  acting  simply  by  chemical  affinity,  and  therefore 
ought  not  to  be  classed  with  true  ferments,  which  are  living 
bodies.  It  therefore  appears  that  carbolic  acid  acts  by  attacking 
vitality  in  some  mysterious  way,  and  where  an  effect  is  merely 
due  to  so-called  catalytic  force,  it  exerts  no  interfering  action. 
39.  The  action  of  carbolic  acid  on  vitality  was  then  tested  in 
other  ways  : — 
XX.  Cheese  mites  were  immersed  in  water,  where  they  lived 
for  several  hours.  A  few  drops  of  a  solution  of  carbolic  acid 
containing  1  per  cent,  added  to  the  liquid,  killed  them  instantly. 
XXL  An  aqueous  solution  of  carbolic  acid  was  added  to  water 
*  These  last  two  experiments  are  confirmatory  of  a  statement  in  Dr. 
Lemaire's  work  "  Sur  l'Acide  Phenique." 
