STEAROPTINE  OF  OIL  OF  MONARDA  PUNCTATA. 
201 
bic  prisms,  composed  of  transparent  plates.  It  melts  at  118°  F. 
and  boils  at  426°  F.,  after  which  the  temperature  may  gradually 
be  reduced  to  82°  F.,  when  it  solidifies  upon  slight  agitation. 
When  a  small  portion  of  eleoptene  is  present,  the  temperature 
may  be  reduced  much  lower  before  crystallization  takes  place. 
According  to  the  analysis  of  M.  Arrpe,  monarda  camphor  (a 
name  which  is  more  applicable  to  this  stearoptene,)  is  composed 
of  C10  H7  0,  being,  as  he  infers,  an  oxide  of  a  compound  radi- 
cal C10  H7 ;  three  equivalents  of  which  radical,  together  with 
an  equivalent  of  oxygen,  he  supposes  to  be  the  constitution  of 
the  eleoptene ;  a  formula  which  makes  it  isomeric  with  cam- 
phrone.  By  the  addition  of  two  equivalents  of  oxygen  to  the 
eleoptene,  there  will  be  formed  three  equivalents  of  the  stearop- 
tene. This  may  explain  the  complete  transformation  of  the  oil 
into  the  camphor  product. 
That  this  solid  substance  is  formed  by  the  absorption  of  oxy- 
gen we  may  prove  experimentally.  If  a  fresh  and  unexposed 
specimen  of  the  oil  be  deprived  of  moisture,  which  is  present  in 
the  distilled  oils,  and  exposed  to  a  low  temperature  in  an  atmos- 
phere of  its  own  vapor,  it  solidifies,  but  resumes  its  fluidity  at 
ordinary  temperatures.  Oil  of  monarda  exposed  to  the  air  or 
to  oxygen  at  32°  F.  soon  begins  to  deposit  the  stearoptene, 
which  is  accelerated  by  the  presence  of  moisture.  It  does  not 
appear  that  it  absorbs  the  water,  as  when  a  portion  has  been 
kept  over  that  fluid  in  a  graduated  tube  so  contrived  that  it  was 
supplied  with  dry  air,  a  large  portion  of  the  camphor  was  de- 
posited, but  the  water  remained  the  same  in  quantity. 
When  either  the  oil  or  stearoptene  is  treated  with  strong 
nitric  acid,  it  is  converted  into  a  resinous  matter.  This  resin 
maintained  at  a  boiling  temperature,  and  treated  with  portions 
of  nitric  acid  until  dissolved,  is  wholly  transformed  into  oxalic 
acid.  When  we  come  to  examine  the  products  of  decomposition, 
we  find  that  the  proportion  of  carbon  in  the  ultimate  product  is 
much  less  than  in  the  oil  which  was  used.  From  the  percentage  of 
oxalic  acid  obtained,  we  may  infer  that  an  equivalent  of  the  oil  is 
converted  into  two  equivalents  of  oxalic  acid,  six  equivalents  of 
carbonic  acid,  and  seven  equivalents  of  water,  with  oxygen 
derived  from  the  nitric  acid,  thus:  C10  H,  0+017  =  2C2  03+ 
6C02+7HO. 
