352 
Essential  Oil  of  Lime  Leaves. 
/  Am.  Jour.  Pharm. 
I       July,  1886. 
taneous  processes,  partly  yielding  compounds  of  the  two  acids,  not 
decomposed  by  water  and  dissolving  therein,  partly  giving  substances 
decomposed  by  water,  which  converts  them  into  the  insoluble  sub- 
stances described  in  the  present  paper. — Jour.  Chem.  Soc,  1886,  p. 
442.— J.  Buss.  Chem.  Soc,  1886. 
ON  THE  ESSENTIAL  OIL  OF  LIME  LEAVES  (CITRUS 
LIMETTA).    Preliminary  Notice. 
By  Francis  Watts,  F.C.S., 
Chemist  to  the  Montserrat  Company,  Montserrat,  W.  I. 
The  leaves  and  young  shoots  of  the  lime  tree  yield  a  fragrant  yellow 
oil  by  distillation  with  water  or  in  a  current  of  steam.  About  230 
c.c.  were  prepared  for  the  purpose  of  the  present  investigation. 
The  oil  is  moderately  soluble  in  rectified  spirit  of  wine,  and  has  a 
sp.  gr.  =  0-8777  at  33°  (water  at  4°  =  1).  When  agitated  with 
soda  solution,  no  appreciable  diminution  of  volume  was  observed. 
The  oil  was  submitted  to  fractional  distillation,  and  the  several 
fractions  were  agitated  with  a  strong  solution  of  sodium  bisulphite. 
It  began  to  distil  at  about  170°,  and  the  portion  which  passed  over 
at  this  temperature  did  not  combine  with  the  bisulphite.  It  consisted 
of  a  hydrocarbon.  On  the  other  hand,  the  fraction  obtained  at  220- 
230°  formed  a  crystalline  mass  with  the  bisulphite.  But  as  this 
fraction  had  no  action,  or  but  very  slight  action,  on  silver  nitrate,  it 
was  inferred  that  it  consisted  of  a  ketone,  rather  than  an  aldehyde. 
About  one-third  of  the  original  oil  boils  at  a  temperature  above 
280°,  has  a  viscid  consistence,  and  exhibits  a  green  fluorescence.  It 
has,  in  fact,  the  appearance  of  colophene,  and  may  possibly  have  been 
produced,  at  least  in  part,  by  the  action  of  heat  in  the  course  of  dis- 
tillation. 
Erom  the  lowest  fractions,  after  digesting  with  sodium,  a  hydro- 
carbon was  separated,  boiling  at  176-177°,  inactive  to  polarized  light, 
and  having  a  refractive  index  at  30°  of  1*4611  for  red  light.  This 
compound  unites  with  hydrogen  chloride,  forming  a  hydrochloride 
which  melts  at  49-50°  in  an  atmosphere  of  hydrogen  chloride.  It 
also  gives  Riban's  color  reaction  with  ferric  chloride.  Except  with 
regard  to  its  action  on  polarized  light,  this  hydrocarbon  resembles  the 
citrenes. 
From  the  action  of  sodium  on  the  lower  fractions  of  the  original 
