AsTptemberPi9iT' }  Therapeutics  and  Chemistry  of  Oxypinenes.  401 
the  animal  organization  ozonized  oil  of  turpentine  acts  more  ener- 
getically than  oil  not  ozonized."  ' 
Since  turpentine,  when  exposed  to  air,  always  absorbs  ozone  and 
oxygen,  forming  ozonide  and  other  oxypinenes,  it  is  safe  to  say  that 
when  the  therapeutical  value  of  turpentine  is  discussed — particularly 
in  the  older  literature,  to  which  the  absorbing  property  of  turpentine 
was  unknown — this  value,  in  equal  or  even  higher  degree,  pertains 
to  the  oxypinenes. 
The  oxidation  of  turpentine  in  sunlight  was  first  mentioned  by 
Sobrero  in  1851.2  Later,  H.  E.  Armstrong,  in  the  course  of  his 
studies  on  the  terpenes  and  camphor,  became  interested  in  the  ex- 
periments of  Sobrero  and  reached  the  same  conclusion  as  he,  that 
"  when  turpentine  is  exposed  to  sunlight  in  the  presence  of  moisture 
and  oxygen  a  crystalline  substance  is  formed,  which  has  a  composi- 
tion represented  by  the  formula  C10H16O2,  and  that  this  substance 
is  decomposed  when  boiled  with  dilute  sulphuric  acid,  an  oil  being 
formed  which  has  a  powerful  odor,  resembling  both  that  of  camphor 
and  that  of  turpentine." 
This  product,  which  was  named  "  Sobrerol  "  in  honor  of  Sobrero, 
is  probably  always  the  initial  product  of  oxidation  of  turpentine.3 
Sobrerol  can  also  be  prepared  from  a  cold  solution  of  pinene  in 
acetic  acid  by  the  action  of  mercuric  acid,  but  if  a  heated  solution  is 
used  the  resulting  oxidation  product  is  hydroxylketone. 
The  turpenes  have  been  used  for  therapeutical  purposes  as  early 
as  the  time  of  Hippocrates,  and  they  were  extensively  employed  by 
the  ancients.  Pliny  appears  to  have  recommended  them  in  many 
diseases  and  Aretaeus  was  also  an  enthusiastic  advocate  of  their  use. 
Ever  since  then  the  turpentines  have  continued  to  keep  their  place 
in  medical  practice.4 
Although  the  ancients  knew  nothing  of  ozone  and  its  absorption 
by  pinene,  and  that  until  1840  nothing  had  been  heard  of  this  life- 
giving  substance,  it  had,  of  course,  existed  since  the  beginning  of 
time  and  been  conducive  to  the  health  of  man. 
The  distilled  oil  of  turpentine  first  made  its  appearance  in  the 
pharmaceutical  literature  in  the  latter  part  of  the  seventeenth  cen- 
tury. In  the  Augsburg  Pharmacopoeia  of  1648  are  given  the  direc- 
tions for  its  preparation,  under  the  title  "  Oleum  Terebenthina." 
2  Compt.  rend.,  vol.  33,  p.  66. 
3  Jour.  Chem.  Soc,  London,  1890. 
4  Med.  and  Phys.  Jour.,  London,  vol.  46,  p.  186. 
