AAPJrTf,m2RM*}  On  the  Fruit  of  Magnolia  Tripetala.  149 
The  crystals  fuse  in  boiling  water  ;  when  they  are  placed  on  the 
surface  of  mercury,  having  a  thermometer  immersed  in  it,  and  a  grad- 
ual heat  applied,  they  were  found  to  fuse  at  180°  F.,  and  not  to  re- 
crystallize  when  the  temperature  falls  ;  when  the  heat  reaches  250°  to 
260°  F.  white  vapors  are  evolved,  which  at  300°  to  320°  F.  are  abun- 
dant, and  cause  coughing  when  inhaled.  When  the  crystals  are  heated 
between  two  watch  glasses  the  vapors  condense  in  minute  transparent 
globules,  like  oil,  which  readily  dissolve  in  alcohol,  and  are  obtained 
in  crystals  by  its  evaporation  ;  only  a  part  of  the  substance  can  be 
thus  obtained — at  least  one-half  of  it  remains  as  a  hard  transparent 
resin.  When  the  heat  is  increased  to  redness  this  is  consumed  with- 
out residue. 
Prof.  Emmet,  of  the  University  of  Virginia,  published  a  paper  on 
Liriodendrin,  the  bitter  principle  of  the  bark  of  the  tulip  poplar 
(Liriodendron  tulipifera),  in  April,  1831  (see  Jour.  Phila.  Coll.  Pharm. 
iii.  5)  in  which  he  describes  minutely  the  characters  of  that  substance. 
He  says  it  exists  in  an  amorphous  (resinoid)  condition,  and  a  hydra- 
ted  or  crystalline  form,  that  it  cannot  be  crystallized  from  its  hot 
concentrated,  alcoholic  solution,  the  liriodendrin  separating  as  a  trans- 
parent varnish. 
When  water  is  added  till  the  alcoholic  solution  becomes  pearl  white 
and  the  temperature  is  kept  at  40°  to  50°  F.,  crystals  are  obtained 
by  spontaneous  evaporation  ;  these  have  different  forms — rhomboidal 
plates,  plumose  or  stellated  prisms,  and  scales  like  boracic  acid.  It 
may  be  washed  with  cold  acid  and  alkaline  solutions  without  any  loss. 
When  gently  heated,  the  crystals  fuse,  slightly  effervesce  (owing  to 
the  escape  of  water),  and  then  become  olive  colored  and  amorphous. 
The  alcoholic  solutions  of  both  varieties  possess  an  intensely  bitter 
taste,  and  leave  an  impression  of  heat  upon  the  tongue.  Crystallized 
liriodendrin  is  brittle,  inodorous,  fusible  at  150°  and  volatile  at  270° 
F.,  but  only  partially  sublimable.  Caustic  potassa  in  strong  solution 
boiled  with  the  crystals  appears  to  convert  them  into  oxalic  acid, 
which  distinguishes  liriodendrin  from  the  resins.  Cold  concentrated 
muriatic  acid  has  no  action  on  it,  but  when  heated  it  effervesces,  and 
assumes  a  deep  emerald  green  color.  Iodine  imparts  to  the  crystals 
by  contact  immediately  a  bright  chrome  yellow  color,  and  forms  an  in- 
soluble grass-green  compound,  which  is  instantly  decomposed  by  ni- 
tric acid. 
Dr.  Stephen  Procter,  in  an  essay  on  the  bark  of  Magnolia  grandi- 
