^y  holding  the  auricle  in  this  position  with  one  hand  and  manipulating
^^e  speculum  with  the  other — a  metallic  conical  speculum  is  the  most
desirable — every  part  of  the  canal  wall  and  drum  membrane  may  be  clearly
^een.    Note  the  size  of  the  canal  and  any  acute  inflammatory  swelling  or
chronic  induration.     The  cartilaginous  portion  of  the  canal  comprises  a
little  over  one-third  of  the  whole  length  of  the  meatus.    Its  junction  with
the  bony  meatus  is  the  most  frequent  site  of  furunculosis.    In  young  chil-
dren the  cartilaginous  meatus  comprises  about  two-thirds  of  the  whole
extent  of  the  canal.      When  a  furuncle  is  of  deep  origin  pus  may  burrow
beneath  the  periosteum  inward  toward  the  tympanic  cavity,  occluding
the  osseous  meatus  entirely  and  giving  rise  to  most  excruciating  pain.    The
pain  within  the  ear  and  swelling  extending  even  back  of  the  auricle  may
be  confused  with  acute  mastoiditis.     In  furunculosis  the  most  acute  pain
is  apt  to  be  elicited  by  pressing  upon  the  tragus,  or,  if  there  be  postauricular
tenderness,  it  will  likely  be  superficial;    in  mastoiditis,  however,  the  pain
may  be  slight  superficially  and  intensified  by  deep  pressure  over  the  mas-
toid, and  pain  is  not  apt  to  be  elicited  on  pressure  over  the  tragus.
When  the  cartilaginous  portion  of  the  canal  is  occluded  by  swelling,
gently  insert  a  tightly  rolled  pledget  of  cotton  dipped  in  a  solution  com-
posed of  camphor  and  carbolic  acid,  equal  parts,  and  allow  it  to  remain  a
few  minutes.  The  swelling  is  thus  sufficiently  reduced  to  allow  the  intro-
duction of  a  small  speculum  for  the  examination  of  the  deeper  canal  and
tympanic  membrane.  This  solution  also  produces  partial  anaesthesia  of
the  membrane,  thus  allowing  a  more  thorough  examination.
228  MEDICAL  DIAGNOSIS.
