Am'Mayri9i5arm'}    Some  Studies  on  the  Oxy-pinenes.  201 
Although  its  medical  properties  were  not  recognized  or  rather 
mentioned,  ozonide  of  pinene  was  well  known  to  chemists  more  than 
ten  years  before  Dr.  Day's  recommendation  of  them.  So,  for  in- 
stance, does  Leopold  Gmelin,  in  his  standard  work,  "  Handbook  of 
Chemistry,"  London,  1850,  vol.  14,  p.  256,  state:  "  Oil  of  turpentine 
absorbs  oxygen  gas,  acquiring  new  properties,  and  being  converted 
into  ozonized  oil  of  turpentine.  In  this  compound  part  of  the  ab- 
sorbed oxygen  appears  to  be  more  intimately,  a  second  part  less  in- 
timately, combined,  inasmuch  as  the  latter  may  be  transferred  to  new 
bodies  and  still  exhibit  the  properties  of  free  oxygen.'' 
This  is  in  perfect  accordance  with  our  modern  conception  of 
pinene  ozonide,  which  is  that,  in  contact  with  water,  only  so  much 
oxygen  is  given  up  to  the  formation  of  peroxide  of  hydrogen  as  is 
not  required  to  form  pinene  aldehyde  and  pinene  aldehyde-peroxide. 
A  little  later,  or  1857,  William  Allen  Miller,  in  his  text-book 
"  Elements  of  Chemistry,"  vol.  3,  "  Organic  Chemistry,"  says :  "  Oil 
of  turpentine  absorbs  oxygen  from  the  air  with  formation  of  certain 
proportions  of  ozone." 
Chas.  T.  Kingzett,  in  the  Journal  of  the  Chemical  Society,  London, 
1874,  vol.  12,  p.  511,  takes  up  these  assertions  and  tries  to  disprove 
them.  He  claims  that  what  really  happens  when  oil  of  turpentine 
absorbs  oxygen  from  the  air — which  fact  he  admits — is  the  formation 
of  monohydrated  oxide  of  turpentine  (C10H16O.H2O) . 
Hardly  a  year  later,  in  the  same  journal,  vol.  13,  p.  210,  he  re- 
tracts this  view  and  considers  the  oxidation  product  of  oil  of  turpen- 
tine to  be  C10H16O4,  which  when  boiled  with  water  forms  peroxide 
of  hydrogen. 
This  almost  exactly  coincides  with  the  formula  of  some  oxy- 
pinene  which  has  recently  been  examined  by  the  author  and  found 
to  have  the  empirical  formula  C10H16O4^5.  This  oxy-pinene  is  un- 
questionably a  mixture  of  pinene  ozonide  and  the  aldehyde  and 
ketones  of  pinene,  whereas  pinonic  acid  can  easily  be  proved  to  be 
absent. 
The  nature  of  ozone  was  in  dispute  for  more  than  twenty  years 
after  its  discovery  by  Schoenbein.  On  one  side  it  was  said  that  it 
was  "  electrified  oxygen,"  on  the  other  that  it  could  not  be  formed 
except  in  presence  of  water,  and  that  it  therefore  must  be  an  oxy- 
compound  of  hydrogen. 
In  his  remarkable  prize-essay,  June,  1861  (printed  in  Boston 
Medical  and  Surgical  Journal,  September,  1864),  Dr.  E.  S.  Gaillard 
