202  Marrubiin  and  its  Dichlorine  Derivative.  {AmAprii?i897arm' 
"  On  the  addition  of  water  to  the  alcoholic  solution,  the  marru- 
biin separates  as  an  oily  liquid,  and  the  mixture  becomes  milky;  on 
adding  some  alcohol  and  allowing  the  solution  to  rest,  the  marrubiin 
crystallizes  out  in  needles. 
"When  heated  on  platinum  foil,  marrubiin  melts  to  a  colorless 
liquid ;  more  strongly  heated,  it  gives  off  white  fumes  of  a  biting 
and  irritating  odor,  and  finally  burns  away  completely  without  leav- 
ing any  ash. 
"  When  heated  in  a  glass  tube  closed  at  one  end  it  distills  over  in 
oily  drops  without  leaving  a  residue,  developing  at  the  same  time 
mustard-oil-like,  piercing  fumes. 
"  The  melting  point  of  marrubiin  lies  at  1600  C;  on  cooling  it 
solidifies  to  a  beautiful,  radiating,  crystalline  mass. 
"  Marrubiin  is  not  a  glucoside.  Concentrated  sulphuric  acid  dis- 
solves it  rapidly,  with  a  brown-yellow  color.  On  the  addition  of 
water  the  color  disappears  with  the  separation  of  gray  flakes. 
"  Concentrated  hydrochloric  acid,  whether  hot  or  cold,  has  no  effect 
on  marrubiin. 
"  Cold  concentrated  nitric  acid  does  not  affect  it,  but  on  heating 
dissolves  it  with  a  yellow  color. 
"  Tannin  does  not  precipitate  a  solution  of  marrubiin. 
"  By  the  action  of  alkalies,  cold  or  warm,  marrubiin  is  not  per- 
ceptibly affected. 
"  Ammoniacal  silver  nitrate  solution,  on  being  boiled  with  mar- 
rubiin, is  only  slightly  reduced.  Marrubiin,  consequently,  is  not  an 
aldehyde-like  body. 
"  Marrubiin  is  not  precipitated  by  metallic  salts,  namely,  ferric 
chloride,  when  applied,  did  not  produce  any  change. 
"In  its  properties  marrubiin  stands  nearest  to  coumarin,  C18H604; 
to  cinnamei'n  (meta-cinnamei'n)  ==  C32H1404  =  C14H70,  C18H703 
(benzoyl-cinnamate) ;  and  to  styracin  ==  C36H1604  =  C18H90,  C18H703 
(cinnamyl-cinnamate)." 
In  addition  to  the  foregoing  results  quoted  from  him,  Kromayer 
remarks  that  marrubiin  is  the  first  instance  of  a  crystalline  separated 
bitter  principle  from  a  plant  belonging  to  the  Labiatae,  a  family 
which  is  so  rich  in  ethereal  oils,  and  that  all  the  characters  of  mar- 
rubiin indicate  its  intimate  relation  to  the  ethereal  oils. 
In  1863  Harms  published  a  second  communication  on  the  prop- 
erties of  marrubiin,  in  Archiv  der  Pharmacie,  No.  116,  p.  141. 
