622  Properties  and  Uses  of  Sozoiodol.  {^'^■ilZ'S^^'"'' 
much  more  soluble  in  warm  water,  and  slightly  soluble  in  glycerin 
and  alcohol.  From  this  body  sozoiodolic  acid  and  all  the  other  salts 
are  prepared.  The  free  acid  crystallizes  from  water  in  the  form  of 
needle-shaped  prisms;  it  is  freely  soluble  in  water,  alcohol,  and  gly- 
cerin. With  regard  to  the  position  of  the  iodine  atoms,  Herr  Oster- 
meyer,  the  discoverer  of  the  body,  considers  that  they  are  in  close 
proximity  to  the  hydroxyl  group.  Various  salts  have  been  prepared  ; 
the  chief  which  have,  however,  been  therapeutically  investigated,  are 
those  of  sodium,  potassium,  zinc,  and  mercury.  The  sodium  salt  is  much 
more  soluble  than  that  of  potassium  ;  it  contains  two  molecules  of 
water,  and  is  soluble  in  cold  water  and  glycerin  to  the  extent  of  6  per 
cent.  The  zinc  salt  is  somewhat  more  soluble.  The  mercury  salt  oc- 
curs in  the  form  of  a  fine  yellow  powder ;  it  is  almost  insoluble  in 
water,  but  pretty  freely  soluble  in  sodium  chloride  solution.  Besides 
these  compounds,  salts  of  aluminium,  magnesium,  lead,  barium,  silver, 
and  ammonium  have  been  prepared.  Sozoiodolic  acid  and  its  salts  are 
effective  antiseptics.  Langgaard^  states  that  an  admixture  of  from  0*5 
to  1  per  cent,  to  gelatine  cultivations  restrained  the  development  of 
streptococcus  pyogenes  aureus.  The  free  acid  being  more  powerful  than 
the  salts,  an  addition  of  2  per  cent,  completely  restrained  the  develop- 
ment of  the  organisms ;  upon  bacteria  of  putrefaction  and  moulds  the 
action  is  not  so  powerful.  Therapeutically,  sozoiodolic  acid  and  its 
salts  have  been  used  chiefly  in  cutaneous  diseases  and  in  affections  of 
the  nose  and  pharynx.  In  the  former  Dr.  Oscar  Lassar  reports  most 
successful  use  of  the  drug,  both  pure  and  with  admixture,  as  dusting 
powder,  and  in  the  form  of  paste,  with  zinc,  starch,  vaselin,  and 
lanolin.  He  states  that  it  is  of  most  decided  service  in  eczema, 
herpes  squamosum,  herpes  tonsurans,  and  impetigo.  He  has  also  used 
it  in  ulcers  and  simple  wounds  with  most  gratifying  success.  He 
states  that  a  10  per  cent,  paste  is  most  successful  in  the  treatment  of 
mycoses.  As  a  dressing  for  sores  sozoiodol  with  talc  is  most  valuable, 
in  many  respects  competing  with  salicylic  acid,  and  unlike  that  substance, 
not  causing  artificial  inflammation  when  applied  in  a  concentrated 
state.  The  use  of  sozoiodol  in  affections  of  the  nose  and  pharynx  is 
reported  on  by  Dr.  M.  A.  Fritsche.^  He  has  had  most  satisfactory 
results  in  the  use  of  the  drug  in  cartarrh,  in  which  the  secretion  has  a 
tendency  to  thicken  and  dry,  e.  g.,  laryngitis  sicca,  rhinopharyngitis, 
1  Therap.  Monaish.,  9, 1>88,  p.  433. 
3  Therap.  Monatsh.,  6,  1888. 
