252  Tasteless  Iodide  and  Chloride  of  Iron.  \^Sg$fl^ 
ON  THE  TASTELESS  IODIDE  AND  CHLORIDE  OF  IRON  * 
New  York,  April  18th,  1873. 
Editor  American  Journal  of  Pharmacy: 
Dear  Sir: — If  you  ask  me  what  kind  of  combination  citrate  of 
potassa  can  form  with  sesqui-iodide  of  iron,  I  will  answer  frankly 
that  I  cannot  say  with  certitude  ;  it  is  probably  a  combination  similar 
to  the  medicinal  pyrophosphate  of  iron  or  the  green  scales  of  sesqui- 
phosphate  of  iron  and  citrate  of  potassa  I  sent  you  last  year.  That 
they  form  a  combination  does  not  admit  of  any  doubt,  for  the  physi- 
cal and  chemical  changes  are  such  as  would  not  be  presented  by  a 
simple  mixture.  But,  be  the  combination  what  it  may,  I  believe  the 
new  salt  represents  exactly  the  results  of  what  happens  in  the  stomach 
when  protoiodide  of  iron  is  administered.  Protoiodide  of  iron  cannot 
be  absorbed  as  it  is,  for  no  protosalt  of  iron  is  ever  found  in  the  ani- 
mal system  ;  when  ingested  into  the  stomach  it  must  change  in  whole 
•or  in  part  into  sesqui-iodide,  which,  combining  with  the  citrates,  tar- 
trates, oxalates,  malates  or  lactates,  etc.,  always  present  in  human 
food,  becomes  ready  for  absorption.  The  balance  of  the  iodide  of 
dron  is  probably  eliminated,  like  all  unabsorbed  substances  (I  leave 
acetates  purposely  out  of  the  list,  for  acetic  acid  is  monobasic,  and 
this  class  of  compounds  seem  to  be  limited  to  the  salts  of  polybasic 
vegetable  acids).  This  explains  also  why  protoiodide  of  iron  is  best 
administered  just  before  a  meal ;  for  the  food  supplies  the  stomach 
with  both  the  oxygen  and  the  vegetable  salts  necessary  for  the  diges- 
tion of  the  ferrous  compound. 
The  new  iodide  of  iron,  according  to  this  theory,  ought  to  be  more 
•effective  and  more  uniformly  so  than  the  protoiodide,  for  it  comes  all 
ready  for  absorption,  while  the  old  salt,  being  absorbed  only  with  the 
help  of  other  variable  substances,  will  vary  more  or  less  in  its  effects, 
besides  interfering  with  the  natural  functions  of  the  stomach. 
Experiments  made  by  Dr.  Lalanne,  of  this  city,  have  confirmed 
this  view  and  have  served  to  determine  the  medicinal  dose  of  the  new 
combination.  This  was  necessary  on  account  of  the  entirely  different 
•character  of  the  new  and  the  old  form  of  iodide  of  iron.  It  has  been 
found  that  from  one  to  three  grains  of  the  salt  have  the  same  medi- 
cinal effect  as  an  average  dose  of  the  U.  S.  Pharmacopoeia  syrup  of 
*The  above  portion  of  a  private  letter  touches  upon  several  interesting  and 
important  points,  and  is  published  with  the  consent  of  the  author  upon  the 
request  of  the  Editor  of  the  American  Journal  of  Pharmacy. 
