142  ESSENTIAL  OIL  OF  VALERIAN. 
and  we  have  in  the  receiver  a  thickish,  slightly  colored,  neutral 
oil,  containing  an  abundance  of  solid  camphreous  matter,  -which 
gives  it  a  strong  smell  like  hay.  This  oxygenated  oil  is  the 
valerol. 
Exposure  to  air  thickens  and  resinifies  it,  but,  contrary  to  the 
assertion  of  Gerhardt,  does  not  develop  any  acid.  It  is  the 
same  with  other  oxidising  agents,  such  as  bichromate  of  potassa 
and  binoxide  of  manganese,  the  influence  of  neither  producing 
any  reaction  on  litmus. 
Valerol  absorbs  a  good  deal  of  ammoniacal  gas  without  form- 
ing a  salt,  another  proof  that  it  does  not  contain  the  acid.  It 
continues  to  boil  from  210°  to  430°,  showing  that  it  has  no 
fixed  boiling  point. 
The  stearoptene  of  valerian  (C^H^Og) — the  crystalline  cam- 
phreous matter  which  we  have  found  in  the  valerol — condenses 
in  great  abundance  in  the  neck  of  the  retort.  At  the  same 
time  a  little  water  is  disengaged,  most  likely  from  that  part  of 
the  valerol  which  is  resinified.  There  remain  in  the  retort  a 
green  resin  (C2  H20O)  and  some  valerianate  of  potassa,  but  I  have 
never  found  this  salt  in  the  residue  of  the  rectification  of  valerol 
over  potassa.  In  the  latter  case  no  oxidising  agent  can  produce 
any  other  than  the  elements  we  have  mentioned,  viz.  the 
steareoptene  of  valerian,  resin,  and  water.  MM.  Gerhardt  and 
Cahours  are,  therefore,  in  error  when  they  say  that  valerol  be- 
comes changed  into  valerianic  acid. 
The  foregoing  may  be  considered  as  an  exact  analysis  of  oil 
of  valerian,  100  parts  of  which  contain  : — 
Valerene  25 
Valerianic-acid        ....  5 
{Steareoptene  of  valerian  18  \ 
Resin  .        .        47  V  70 
Water  •        .  5j 
100 
The  preceding  facts,  I  believe,  prove  :  1.  That  the  essential 
oil  does  pre-exist  in  the  fresh  plant ;  2.  That,  fresh  or  old,  it 
always  contains  about  5  hundredths  of  valerianic  acid  ;  3.  That 
rectified  over  potassa  it  is  perfectly  neutral ;  4.  That  it  con- 
tains two  oils  :  the  one  a  hydrocarbon  (C20H16)  or  valerene, 
