Am  Au^'Sarm'}  Botany  and  Chemistry  of  Essential  Oils.  405 
Rhodinol,  isomeric  with  geraniol,  is  the  elaeoptene  contained  in 
rose  oil,  and  may  be  represented  by  a-propyl  <r-propylcrotonylene- 
methylcarbinol — 
CH2 :  CPrCH  :  CH  CHPr-CH2OH 
These  bodies,  though  of  same  empirical  composition  as  the  cam- 
phors, differ  greatly  from  them,  but  they  are  very  closely  allied  to 
each  other.  They  exist  in  plants  of  widely  different  orders,  and, 
no  doubt,  further  research  will  prove  them  to  be  contained  in  other 
oils.  Closely  allied  with  them  in  the  oils  are  the  alkyl  salts  of  these 
alcohols — generally  the  acetate. 
Geraniol  acetate,  C10H17CH3CO2,  occurs  in  oils  of  lemon,  berga- 
mot,  linaloe  and  lavender  ;  and  aurantiol  acetate,  either  identical  or 
isomeric  with  the  above,  in  oil  of  petit  grain.  These  we  should 
expect  to  be  fragrant  bodies,  recalling  the  alkyl  salts  of  amyl  and 
valerian,  and  in  A.  nobilis  we  have  amyl  and  butyl  tiglinates  and 
angelicates  with  other  alkyl  salts.  This  I  think  is  a  fair  and  general 
account  of  the  bodies  belonging  to  the  aliphatic  series,  and  before 
passing  to  the  phenol  compounds,  I  shall  give  an  example  of  the 
constituents  of  an  oil  showing  how  my  generalization  applies. 
Oil  of  bergamot  {Citrus  Bergamia)  contains  : 
40  per  cent,  limonene  1 
(t        •,.      ,.       V  terpenes  described  under  that  head. 
10  dipentme  j  r 
25       "       geraniol — alcohol  CxoHi  80. 
20       "       geraniol  acetate. 
5       "       bergaptene.  * 
Bergaptene  is  a  body  supposed  to  be  the  lactone  of  bergaptenic 
acid,  a  body  allied  to  coumann,  and  would  be  represented  thus : 
CH    —   C— COCH3^C— CH— CH 
II  II  II 
CH— O— C— CH=      C— O—  CO 
Bergaptene. 
We  see,  therefore,  in  this  oil  the  terpenes,  alcohol  and  alkyl  salt, 
and  another  body  in  very  small  quantity  and  possibly  formed  from 
others. 
1  now  pass  on  to  those  constituents  which  belong  to  the  benzene 
group  proper,  though  thymol  described  under  camphors  really 
comes  under  this  category,  but  most  of  them  may  be  regarded  as 
derived  from  benzene  rather  than  paracymene. 
