32  Antiseptic  Value  of  Chemical  Preparations.  {Am  ji0nuy\£lfrm' 
of  iodoform  checked  the  growth  of  tubercle  bacilli  in  blood  serum, 
but  as  the  growth  of  these  bacilli  is  but  slow,  he  cannot,  as  yet, 
decide  whether  in  this  case  also  the  result  is  due  to  the  reducing 
power  of  the  germs. 
As  a  rule,  the  more  a  bacteria  culture  stinks,  the  more  certainty  is 
there  that  the  germs  are  rapid  decomposers,  and  that  iodoform  will 
check  their  growth.  Thus,  it  is  not  on  the  staphylococcus  of  laudable 
pus  that  iodoform  acts  to  any  great  extent,  but  on  the  germs  that  in 
stinking  pus  we  find  alongside  the  staphylococci. 
It  has  been  held  that  iodoform  acts  on  the  ptomaines,  but  to  this 
theory  Behring  is  opposed.  Iodoform  acts  before  the  ptomaines  are 
produced,  and  besides,  these  very  ptomaines  of  themselves  hinder  the 
development  of  pus. 
Carbolic  acid,  once  the  sovereign  antiseptic,  naturally  led  us  to  think 
that  iodoform  would  behave  in  a  similar  fashion,  and  hence  the  mis- 
takes. As  a  disinfectant,  carbolic  acids  have  the  advantage  of  acting 
almost  equally  well  in  checking  in  almost  all  circumstances  the  growth 
of  germs.  In  the  presence  or  absence  of  albumen,  in  acids  or  alkalies, 
against  aerobic  or  anaerobic  bacteria,  carbolic  acid  acts  almost  equally 
powerfully.  This  is  due  likely  to  its  molecule,  difficult  to  break  up, 
and  very  prone  to  piece  itself  together  again.  In  oils  and  in  alco- 
holic and  resinous  substances  it  is  inert,  but,  as  in  wound  discharges, 
etc.,  it  quits  these  and  slips  into  the  water  of  the  discharge,  it  is  prac- 
tically active,  although  in  these  media. 
Perchloride  of  mercury,  used  by  Bergman  (1878)  for  impregnating 
dressings,  and  described  and  praised  by  E.  Koch  (1881)  as  the  strongest 
i  and  best  antiseptic,  did  not  in  practice  come  up  to  the  exact  figures  given 
by  Koch,  and  the  reproach  thrown  out  was  that  "  the  human  body  was 
no  test  tube.'7  Koch's  experiments  regarded  the  antiseptic  value  of 
the  perchloride  as  tested  by  its  action  on  the  germs  in  broths  and  gel- 
atin. It  was  next  discovered  that  the  perchloride  varied  in  its  action 
in  albuminous  and  non-albuminous  media,  in  concentrated  and  weak 
solutions  and  at  different  temperatures.  It  might  have  been  discov- 
ered also,  adds  Behring,  that  albuminous  media,  in  which  bacteria  are 
already  developed,  have  the  property  of  reducing  the  perchloride  of 
mercury  to  calomel,  and  even  to  metallic  quicksilver.  Of  course  the 
antiseptic  action  is  gone.  Here  we  have  an  antiseptic  differing  entirely 
from  iodoform  in  its  method  of  action.  After  these  general  remarks, 
our  author  gives  in  long  detail  the  results  of  his  numerous  elaborate 
