26 
ON  THE  CHEMICAL  HISTORY  OF  LUPULIN. 
niunicates  its  odor,  this  solution  is  quickly  acidified  on  exposure 
to  the  air.  The  oil  is  soluble  in  alcohol  and  ether,  at  2°  F.  it 
thickens  but  retains  its  transparence,  and  its  circular  polarization 
is  right  handed. 
Sulphuric  acid  colors  it  red  and  unites  with  a  portion  forming 
a  copulated  acid  whose  baryta  salt  is  soluble  in  water.  Nitric 
acid  colors  it  purple  at  first,  but  if  heated  slightly  it  reacts 
quickly  with  the  production  of  valerianic  acid  and  resin.  A 
concentrated  solution  of  potassa  when  mixed  with  the  oil  and 
exposed  to  the  air  forms  valerianate  of  potassa  and  a  resinous 
matter.  Fused  potash  transforms  it  into  carbonate  and  valerian- 
ate of  potassa  with  the  disengagement  of  hydrogen  and  a  li- 
quid hydro-carbon.  This  reaction  with  potassa  is  important, 
because  after  many  unsuccessful  attempts  and  a  great  number  of 
analyses  it  is  this  which  has  developed  the  true  nature  of  this 
essence  and  placed  it  beside  the  oil  of  valerian.  By  repeated  rec- 
tification from  potassa  M.  Personne  obtained  light  oil  having  the 
formulae  C10  II8,  which  boils  at  320°  F.  and  which  is  isomeric 
with  the  borneen  of  oil  of  valerian.  The  action  of  potassa  fusa 
on  oil  of  lupulin  (or  hops)  consists  in  eliminating  the  liquid  hy- 
dro-carbon C10  H8,  and  in  retracing  an  oxygenized  body  which, 
like  the  oil  of  valerian,  it  transforms  into  carbonic  and  valerianic 
acids,  and  which  is  isomeric  with  valerol. 
The  crude  oil  C56  Hi6  O6  may  be  considered  as  a  mixture  of 
the  body  C10  Hs  with  a  body  C12  H10  O2  thus ;  3  (C12  H10  O2)  +  2 
(C10  IIs).  Whilst  the  purified  oil  obtained  between  the  tempe- 
ratures of  300  and  320°  may  be  viewed  as  C22  II1S  O2  =  C12 
H10  Q2  +  Q10  H8. 
When  the  solid  residue  of  lupulin,  left  after  distilling  the  oil, 
is  dried  and  exhausted  with  alcohol,  it  affords  a  resinous  sub- 
stance which  is  transformed  into  valerianic  acid  by  the  action 
of  potassa.  On  mixing  this  solid  residue  with  slacked  lime,  and 
distilling  at  a  temperature  below  that  necessary  to  char  it,  a 
brown  oily  liquid  is  obtained,  having  a  penetrating  odor.  This 
oil,  when  rectified,  furnishes  a  liquid  boiling  at  194°  F.,  having  a 
penetrating  ethereal  odor,  scarcely  soluble  in  water,  very  solu- 
ble in  alcohol  and  ether,  and  without  action  on  litmus.  The  den- 
sity of  this  liquid  is  0.8009. 
This  body  absorbs  oxygen  from  the  air  very  readily  and  ra- 
