26  Modern  Surgical  Dressings.  {AjanuaryPi897.m' 
These  bacteria  are  widely  distributed. 
"  There  is  no  well-defined  dividing  line  between  pathogenic  and 
non-pathogenic  bacteria." — Sternberg. 
It  would  be  impossible  in  the  manipulation  of  dressing  material 
to  separate  or  remove  harmless  bacteria  from  those  which  may  be 
virulent.  Therefore,  in  its  practical  application  the  fulfillment  of 
the  law  demands  that  surgical  dressings  shall  be  free  from  all  forms 
of  bacteria. 
All  antiseptic  agents  do  not  possess  the  power  to  destroy  or  kill 
organisms.  Therefore,  dressings  impregnated  with  antiseptics  will 
not,  of  necessity,  meet  the  demand.  Hence,  in  the  preparation 
of  surgical  dressings,  the  law  must  be  construed  to  mean  that,  what- 
ever may  be  the  material  and  whatever  may  be  the  methods  by 
which  it  may  be  prepared,  in  order  to  meet  the  requirements  of 
surgery,  the  fundamental  principle  governing  its  production  must 
provide  that  it  shall  be  free  from  all  micro-organisms. 
The  Infection  of  Dressings. — The  materials  which  enter  into  sur- 
gical dressings,  such  as  absorbent  cotton,  gauze,  wool,  are  those 
which,  in  themselves,  reach  after,  absorb  and  hold  bacterial  life. 
Every  person  and  every  object  with  which  the  dressing  may  come 
in  contact  in  the  course  of  its  preparation,  are  liable  to  transfer  to  it 
infection.    Infection  through  air  is  a  possible  factor. 
Micro-organisms  are  readily  disseminated  through  the  air  by  the 
medium  of  dust.  The  air  of  a  crowded  room  is  always  laden  with 
bacterial  life.  In  hospitals,  the  air  is  infected  through  the  dis- 
charges of  patients.  The  air  of  a  physician's  office  cannot  be  kept 
free  from  infected  dust.  The  dust  on  the  drug-store  counters,  tables 
and  shelves  will  always  furnish  a  luxuriant  bacterial  garden. 
Wherever  people  move  about,  they  must,  of  necessity,  transfer  soil 
and  create  dust.  If  they  move  from  infected  centres,  as  do  the 
inmates  and  attendants  at  hospitals,  the  visitors  to  the  doctor's 
office  or  the  patrons  of  a  drug  store,  they  spread  infected  dust. 
Dressings  may  also  become  infected  through  the  water  used  in 
their  preparation.  The  water  used  upon  the  dressings  should 
always  be  that  which  is  boiling  or  which  has  been  thoroughly  boiled. 
A  greater  source  of  infection  arises  from  contact  with  the  person 
who  handles  the  dressing  in  the  course  of  its  preparation.  Here 
the  clothing  of  the  operator  is  a  possible  germ  carrier  ;  his  body  is 
swarming  with  bacteria  numerous  in  species,  in  uncountable  num- 
