Intelligence  and  Miscellaneous  Articles.  547 
each  memoir  must  be  accompanied  by  a  sealed  packet  bearing  on 
the  outside  the  same  motto  as  the  memoir,  and  enclosing  the  name, 
profession,  and  address  of  the  author.  The  value  of  the  gold  medal 
is  stated  at  450  francs. 
ANOMALOUS    PRODUCTION    OF     OZONE.         BY    HENRY    H.    CROFT, 
PROFESSOR  OF  CHEMISTRY,  UNIVERSITY  COLLEGE,  TORONTO. 
About  six  years  ago,  when  evaporating  some  syrupy  iodic  acid, 
prepared  according  to  Millon's  process,  over  sulphuric  acid,  I 
noticed  that  when  the  acid  began  to  crystallize  the  air  in  the  jar 
(covering  the  drying-dish)  had  a  strong  smell  of  ozone  or  active 
oxygen.  A  couple  of  years  afterward,  on  again  making  iodic  acid, 
this  observation  recurred  to  my  mind,  and  I  carefully  tested  the  air 
in  the  jar  during  the  evaporation ;  no  trace  of  ozone  could  be  de- 
tected until  the  acid  began  to  crystallize,  when  the  smell  of  ozone 
became  immediately  perceptible,  and  all  the  usual  tests  for  that  body 
succeeded  perfectly. 
During  the  last  month  I  have  had  occasion  to  convert  two  ounces 
of  iodine  into  iodic  acid;  and  exactly  the  same  result  has  been 
observed. 
The  acid  usually  solidifies  to  opaque  verrucose  masses ;  but  on 
this  occasion  the  crystals  formed  were  clear  and  brilliant.  The 
solution  had  in  this,  as  in  all  the  former  cases,  been  boiled  down 
to  thin  syrup,  so  that  no  trace  of  chlorine  or  nitric  acid  could  pos- 
sibly have  remained  to  act  on  the  ozone  paper.  The  air  in  the  jar 
was  tested  from  day  to  day  both  by  the  smell  and  the  action  of 
iodized  starch-paper.  Even  when  a  few  crystals  began  to  form,  no 
change  was  noticed  ;  but  when  the  crystallization  set  in  fully,  the 
evolution  of  ozone  was  most  remarkable,  the  strong  smell  being 
quite  characteristic,  entirely  different  from  that  of  chlorine  or  nitric 
acid. 
I  am  quite  unable  to  account  for  this  ozonification  of  the  air  (or 
oxygen)  over  crystallizing  iodic  acid.  My  friend,  Mr.  Sterry  Hunt, 
has  suggested  that  it  may  arise  from  a  partial  deoxidation  similar 
to  that  which  produces  ozone  when  hypermanganates  are  decom- 
posed, as  observed  by  him  and  other  chemists.  As  the  crystallizing 
acid  remains  perfectly  white,  either  opaque  or  transparent,  and  as 
the  lower  oxides  of  iodine  are  of  a  yellow,  or  even  brown  colour, 
according  to  Millon,  I  cannot  accept  this  explanation  ;  and  even  if 
it  were  true,  the  phenomenon  would  be  equally  unintelligible,  a 
reduction  taking  place  during  crystallization.  I  can  offer  no  expla- 
nation of  the  simple  fact  that  air  over  crystallizing  pure  iodic  acid 
becomes  ozonized ;  but  I  think  that  the  observation  seems  to  offer 
a  wide  field  for  further  experiments,  which  I  have  unfortunately  not 
the  time  to  carry  out. — Silliman's  American  Journal  for  June  1872. 
