ON  THE  CHEMICAL  HISTORY  OF  LUPULIN. 
25 
Volatile  acid  of  Lupulin. — After  separating  the  volatile  oil, 
the  distilled  water  was  saturated  with  carbonate  of  soda  and 
evaporated  to  dryness.  The  dry  mass  dissolved  in  a  little  water 
was  treated  with  sulphuric  acid  mixed  with  an  equal  weight  of 
water,  which  formed  sulphate  of  soda,  and  liberated  a  brown  oily 
liquid  which  floated  on  the  saline  solution,  and  which  emitted  a 
penetrating  odor  of  butyric  and  valerianic  acid. 
Submitted  to  distillation.,  this  oily  liquid  commences  boiling  at 
266°  F.,  and  the  temperature  becomes  stationary  at  347°  F.  for 
some  time,  and  finally  rises  to  356  and  392°.  By  repeated  rec- 
tifications the  boiling  point  becomes  stationary  at  347°  and  the 
liquid  distills  without  alteration. 
This  acid,  obtained  in  a  state  of  purity,  is  a  slightly  oleagi- 
nous liquid  very  fluid,  colorless,  a  strong  and  persistent  odor  of 
valerianic  acid  ;  its  taste  acid  and  pungent ;  it  produces  a  white 
spot  on  the  tongue  like  the  strong  fatty  acids  ;  it  is  not  solidified 
at  4°  F.,  and  burns  with  a  sooty  flame.  Its  density  at  59°  F. 
is  0.9403. 
Burnt  with  oxide  of  copper  it  gave  C  58.64  II  9.91  0  31.45 
which  is  equivalent  to  the  formula  C10  H10  O4  or  C10  H9.  031-  HO. 
Both  the  silver  and  baryta  salts  of  this  acid  were  analysed  and 
afforded  results  corresponding  to  the  above.  The  acid  in  lupu- 
lin  is  therefore  valerianic  acid,  a  fact  corroborated  by  the  odor 
of  the  lupulin. 
Volatile  oil  of  Lupulin  This  volatile  oil,  in  its  crude  state, 
is  an  oleaginous  liquid,  more  or  less  fluid  according  to  the  age  of 
the  lupulin  yielding  it,  and  is  lighter  than  water.  It  has  always 
an  intense  yellowish  green  or  fine  green  color  ;  its  «dor  recalls 
that  of  the  hop,  but  does  not  resemble  that  of  valerianic  acid, 
unless  the  oil  has  become  oxidized  by  exposure. 
When  heated  it  commences  to  boil  at  282°  F.,  and  boils  for 
some  time  between  300  and  320°  F.,  after  which  the  boiling 
point  rises  to  572°  F.  Heat  acts  injuriously  on  the  oil,  a  part 
being  changed  in  the  process  of  rectification. 
That  portion  of  the  purified  oil  obtained  between  300  and 
320°  is  a  very  fluid  liquid,  having  a  light  amber  color,  an  odor 
which  does  not  recall  that  of  the  hop,  and  a  density  of  0.8887. 
It  has  no  acid  reaction,  but  exposed  to  the  air  it  becomes  acid 
and  resinous :  it  is  but  slightly  soluble  in  water,  to  which  it  com- 
