206  Some  Studies  on  the  Oxy-pinenes.    { Am  Ma°Juri9p15arm- 
alcohol,  ether,  and  chloroform,"  and  in  general  does  his  description 
of  this  oxidation  product  of  turpentine  tally  exactly  with  the  one 
Harries  definitely  identified  as  ozonide  of  pinene. 
That  the  oxidizing  of  turpentine  by  ozone  was  not  entirely  un- 
known by  this  time  seems  to  appear  from  the  discussion  of  a  paper 
read  by  Colonel  W.  J.  Engeldue  to  the  Society  of  Chemical  Industry 
on  December  5,  1898,  in  which  Mr.  W.  F.  Reid  remarks :  "  For  ages 
turpentine  has  been  used  as  an  oxygen-carrier,  and  it  is  not  surprising, 
therefore,  that  it  was  now  found  to  be  a  useful  carrier  for  ozone  " ; 
and :  "  When  ozone  passed  through  turpentine  white  vapors  were 
given  ofT  of  an  intensely  active  character."  Here  again  we  meet  the 
white  vapors  described  by  Dr.  Bertram  H.  Waters. 
After  Schoenbein  had  discovered  ozone  he  began  the  study  of 
the  absorption  of  oxygen  by  turpentine  from  the  atmosphere,  and  has 
given  the  result  of  his  investigations  in  a  series  of  articles  (Journ. 
pr.  Ch.,  vols.  52,  53,  54,  66,  and  67;  Ann.,  vol.  102,  and  Jahr.,  1851, 
1859,  and  i860),  in  which  he  advances  the  theory  that  the  oxygen 
is  transformed  by  the  turpentine  to  ozone,  and  ascribes  its  chemical 
properties  to  this  fact. 
This  theory  is  hotly  contended  by  a  number  of  chemists,  such  as 
Berthelot  {Jahr.,  1859,  and  C.-B.,  1861)  and  Houzeau  {Jahr.,  i860), 
who  claim  that  oxygen  can  be  absorbed  by  turpentine  only  in  the 
presence  of  water,  and  then  forms  a  peroxide  of  pinene.  This 
view  is  supported  by  Kingzett  {Journ.  of  Chem.  Soc,  vol.  27 ;  Pharm. 
Journ.,  Ber.,  3,  vols.  5,  6,  9,  and  20;  Ber.,  vol.  29,  and  Jahr.,  1876), 
who  tries  to  prove  that  the  oxidation  takes  place  by  the  turpentine 
first  forming  peroxide  of  camphene  and  then  peroxide  of  hydrogen 
and  oxy-pinene  according  to  the  reaction  C10H16O4  +  2H20  =  H202 
+  C10H16O4. 
Closely  allied  to  this  point  of  view  are  the  opinions  of  Bradsky 
{C.-B.,  1882),  Schaer  {Ber.,  vol.  6),  and  Papasogli  {Jahr.,  1876,  and 
C.-B.,  1888).  They  all  fail,  however,  to  explain  why — if  this  is  the 
case — the  oxy-pinene  formed  gives  reactions  which  the  peroxide  of 
hydrogen  does  not;  for  instance,  liberates  iodine  from  potassium 
iodide. 
In  order  to  explain  away  this  troublesome  fact  another  hypothesis 
was  advocated  by  Engler  and  Wild  {Ber.,  vol.  30),  Engler  and 
Weissburg  {Ber.,  vol.  31),  Engler  {Ber.,  vol.  33),  Engler  and 
Frankenstein  {Ber.,  34),  and  particularly  in  a  monograph  by  Engler 
and  Weissburg,  "  Uber  die  Auto-oxidation." 
