208  Some  Studies  on  the  Oxy-pinenes.  {Km^r\^vm' 
In  the  same  year  P.  Fenaroli  and  E.  Molinari  each  published  ac- 
counts of  oxidation  by  ozone,  but  without  giving  the  decomposi- 
tion products,  in  Annuario  della  Societa  Chimica  de  Milano.  The 
real,  systematic  investigation  of  the  ozonides,  however,  was  begun  a 
year  later,  when  Harries  described  the  preparation  of  ozonides  in 
two  different  ways  {Ber.,  vol.  37,  1). 
The  first  method  is  to  let  the  ozone  act  directly  on  the  substance 
without  any  solvent  and  in  the  cold — the  temperature  is  kept  low 
and  moisture  excluded  by  a  current  of  carbon  dioxide — and  the 
second  to  act  on  the  substance  to  be  oxidized  in  a  solution  in  presence 
of  water. 
He  finds  that  in  the  first  case  peroxide  of  hydrogen  is  not  formed, 
whereas  in  the  second  case  it  is  invariably  formed.  In  the  same 
volume  of  the  Berichte  are  two  articles  by  Harries  and  A.  S.  Oza 
and  Harries  and  Richard  Weil,  which  fully  establish  that  the  ozone 
molecule  enters  into  the  combination  with  different  hydrocarbons  and 
fatty  acids  of  the  oleic  series  by  direct  addition,  and  are  entirely  dis- 
tinct chemical  compounds,  with  a  different  linking  from  any  other. 
In  an  exhaustive  article  published  in  Liebig's  Annalen  der  Chemie, 
entitled  "  Ueber  die  Einwirkung  des  Ozons  auf  organische  Verbin- 
dungen,"  1907,  (vol.  343,  pp.  311-374),  Harries  gives  a  full  account 
of  his  work  on  the  ozonides.  He  is  now  able  to  state  that  the  ozonides 
in  general  are  "  heavy  oils  or  water-glass  like,  almost  colorless  liquids 
of  more  or  less  explosive  character,"  and  that  their  formation  takes 
place  in  the  following  way  : 
\c  =  c/  +  o  =  o  =  Nc  -  c( 
and  that  when  they  come  into  contact  with  water  they  are  decom- 
posed into  aldehydes  or  ketones  and  peroxide  of  hydrogen  in  the  fol- 
lowing manner : 
>c  -  c< 
I  +H20  =  NC0  +  0C</  +  H202 
In  this  dissertation,  "  Zur  Kentniss  der  Dialdehyde  und  Ketoalde- 
hyde,"  Kiel,  1905,  Hans  Tuerk  takes  advantage  of  this  fact  pointed 
out  by  Harries,  and  proves  its  correctness  by  preparing  a  large  num- 
ber of  aldehydes  direct  from  the  ozonides. 
