80 
IODIDE  OF  CADMIUM. 
^infrequently  becomes  brown  from  liberation  of  free  iodine ;  now 
although  these  inconveniences  may  be  removed  by  proper  man- 
agement and  care  as  to  the  purity  of  the  drug,  nevertheless  I  am 
disposed  to  look  upon  the  salt  when  mixed  with  fatty  substances 
as  not  very  readily  absorbed  by  the  skin,  and  consequently  not 
well  adapted  to  produce  the  peculiar  local  effects  of  iodine,  which 
it  is  often  so  advantageous  to  obtain  ;  for  it  must  be  remembered 
that  iodine  is  not  always  used  simply  for  its  rubefacient  or  coun- 
ter-irritant action. 
The  ointment  of  iodide  of  lead  likewise  possesses  certain  objec- 
tionable qualities.  Although  not  irritant  to  the  skin,  still  it 
stains  the  cuticle  yellow.  And  again,  I  consider  the  long-con- 
tinued use  of  lead  is  undesirable  ;  for  we  know  that  it  is  apt  to 
induce  many  injurious  effects  when  absorbed  into  the  system,  lead 
cachexia,  colic,  and  different  forms  of  paralysis,  as  wrist  drop, 
&c.  ;  these  may  occur  even  when  very  minute  quantities  are  in- 
troduced, and  such  absorption  might  readily  take  place  when  the 
preparations  are  employed  for  any  lengthened  period  around 
diseased  joints,  or  over  enlarged  glands. 
%  I  believe,  however,  that  iodide  of  cadmium  possesses  all  the 
valuable  qualities  of  iodine,  iodide  of  potassium,  or  iodide  of  lead, 
when  applied  externally,  and  at  the  same  time  it  is  free  from  the 
various  noxious  properties  of  these  preparations.  The  salt  occurs 
in  the  form  of  mother-of-pearl-looking  plates  or  six-sided  tables, 
quite  white  and  transparent,  unaltered  in  the  air,  very  readily 
soluble  both  in  water  and  alcohol,  consisting  of  equal  equivalents 
of  iodine  and  cadmium,  or  69.46  per  cent,  of  iodine  and  30.54 
per  cent,  of  cadmium.  It  is  readily  distinguished  by  giving  the 
blue  color  with  starch  and  chlorine,  and  the  characteristic  yellow 
precipitate  with  sulphuretted  hydrogen.  It  forms  a  perfectly 
white  and  soft  ointment,  producing  but  little  local  action  upon 
the  skin,  and  appearing  to  be  readily  absorbed  when  properly 
applied  with  friction. 
Under  the  use  of  an  ointment  of  this  salt,  consisting  of  one 
part  of  the  iodide  to  eight  parts  of  lard,  I  have  witnessed  in  many 
cases  enlarged  scrofulous  glands,  rapidly  reduced  to  their  normal 
dimensions,  great  relief  likewise  given  in  various  forms  of  nodes, 
and  have  also,  in  several  instances,  seen  much  advantage  from 
its  application  to  joints  affected  with  chronic  forms  of  inflamma- 
