416 
Qiiiniiir  TofJate  (uid  Bromafc 
( Am.  Jour.  Phariu 
"(     August,  1882. 
method  of  repmsentatioii  the  molecule  is  constituted  as  follows^ 
K— I. 
Although  potassium  iodide  is  a  saturated  and  a  stable  body,  three 
or  four  atoms  of  oxygen  may  be  combined  with  it  so  as  to  form  potas- 
sium iodate  (KIO3)  or  potassium  periodate  (KIOJ.  In  the  latter  salt 
only  two  of  the  atoms  of  oxygen  are  in  union  with  the  potassium  and. 
iodine,  six  oxygen  bonds  satisfying  each  other,  K — () — O — O — O — I.. 
In  this  compound  there  are  three  atoms  of  oxygen  in  excess  of  the 
number  re(piisite  to  saturate  the  iodine  and  potassium ;  hence  we  may 
term  potassium  periodate  a  superoxidized  compound. 
Periodic  anhydride  is  a  more  striking  example  of  a  superoxidized 
body.  It  is  composed  of  tAvo  atoms  of  iodine  combined  with  seven  of 
oxygen,  I — O — O — O — O — O — () — O — I.  In  this  compound  only 
two  of  the  fourteen  oxygen  bonds  are  in  combination  with  the  iodine.. 
It  may  of  .course  be  said  that  iodine  is  a  septivalent  element,  but  in 
atom-iixing  power  it  acts  in  general  like  other  monads. 
If  we  hold  that  iodine  ajid  l)romine  are  m<jnads,  then  the  higher 
terras  of  their  oxygen  series  may  be  regarded  as  in  reality  unsaturated 
molecules.  They  contain  oxygen  atoms  combined  only  with  other 
oxygen  atoms.  Such  compounds  are  unstable.  They  are  all  decom- 
posed by  simple  heat  at  comparatively  low  temperatures. 
When  superoxygenated  compounds  are  introduced  into  the  system^ 
it  might  be  expected  that  their  oxygen  being  loosely  combined  would 
unite  readily  with  elements  of  the  blood.  It  is,  hoAvever,  stated  that 
potassium  chlorate  passes  through  the  body  unchanged.  It  is- open  to 
doubt  whether  or  not  the  whole  of  the  chlorate  taken  appears  subse- 
quently in  the  urine.  It  has  been  alleged  that  quinine  passes 
unchanged  through  the  body,  but  it  is  now  known  that  only  twx)-thirds 
of  the  quinine  taken  into  the  stomach  can  be  detected  subsequently  in 
the  urine.  Even  if  all  the  potassium  chlorate  taken  were  found  after- 
wards in  the  uriiie,  that  would  not  be  positive  proof  that  the  potas- 
sium chlorate  had  not  been  partially  deoxidized  and  reoxidized  in  its 
passage  through  the  system.  Besides  drugs  produce  powerful  catalytic 
effects  Avithout  undergoing  themselves  any  chemical  changes. 
Potassium  iodate  appears  to  act  more  powerfully  upon  the  system, 
than  potassium  iodide.  I  know  a  person,  accustomed  to  take  ten  grain 
doses  of  potassium  iodide  Avithout  experiencing  any  unpleasant  symp- 
toms, Avho  cannot  take  even  five  grains  of  the  iodate  Avithout  being- 
attacked  by  coryza. 
