312 
ON  LUPULINE. 
the  hops,  their  bitterness  and  aroma,  are  due.  It  has  been  in- 
vestigated by  D.  Ives,  of  New  York,  and  by  Payen  and  Cheva- 
lier.   (Also  by  Dr.  Rudolph  Wagner.) 
Lupuline  furnishes  both  volatile  and  non-volatile  bodies  to 
boiling  water.  When  distilled  with  water,  an  acid  and  an  essen- 
tial oil  pass  over  as  volatile  constituents.  The  non-volatile  sub- 
stances are  an  organic  acid  and  nitrogenous  bitter  matter,  both 
of  which  are  soluble  in  water.  The  author  has  not  investigated 
these  any  further. 
The  volatile  acid,  determined  by  the  analysis  of  the  salts  of 
silver,  baryta  and  copper,  is  valerianic  acid,  of  which  lupuline 
contains  about  one  per  cent. 
The  volatile  oil  is  lighter  than  water,  becomes  resinified  in  the 
air,  and  acquires  acid  properties.  The  boiling-point  rises  from 
284°  to  572°  F.  By  fractional  distillation,  the  author  separated 
it  into  two  different  oils.  One  boils  between  802°-320°  F.,  the 
other  at  572°  F.  Both  have  the  constitution  C22  Hlst>2;  they 
turn  the  plane  of  polarization  to  the  right,  and  do  not  solidify 
at  0°  F.  Concentrated  sulphuric  acid  dissolves  them  with  a  red 
color  ;  they  are  again  separated  by  water,  and  the  sulphuric  acid 
then  furnishes  with  baryta  a  salt  of  a  conjugate  sulpho-acid ; 
nitric  acid  converts  them  partly  into  resin  and  partly  into  vale- 
rianic acid.  If  let  fall  in  drops  upon  hydrate  of  potash,  they 
are  converted  into  a  hydrocarbon  of  the  formula  C10  Hs,  with 
formation  of  carbonic  and  valerianic  acids.  If  this  hydrocarbon 
be  deducted  from  the  oil,  C22  H18  O2—  C'°  H8=Cla  Hlfl  O2,  the 
latter  expresses  the  valerole  which  Gerhardt  prepared  from  va- 
lerianic acid.  The  hydrocarbon  of  the  oil  of  hops,  however,  fur- 
nishes no  Borneo  camphor,  and  it  also  has  a  smell  more  like  that 
of  thymene. 
The  large  quantity  of  resin  contained  in  lupuline  renders  it 
difficult  to  obtain  valerole  from  it.  The  solid  resinous  mass  left 
after  exhaustion  with  water  consequently  still  contains  much  of 
this  substance.  If  it  be  distilled  with  lime,  taking  care  that  it 
is  not  carbonized,  Chancel's  aldehyde  of  valerianic  acid  goes 
over;  its  composition  is  C:o  H10  O2.  It  boils  at  194°  F.,  and  is 
rendered  brown  and  resinous  by  potash,  and  very  readily  reduces 
salts  of  silver.  Its  specific  gravity  was  0-8009  at  68°  F  Lon- 
don Chem.  Gaz.  from  Comptes  Rendus. 
