164 
Bhododendron  Maximum, 
J  Am.  Jour.  Pharm. 
(       April,  1885. 
RHODODENDRON  MAXIMUM,  Linn^. 
(great  laurel.) 
Natural  Order,  Ericacece;  sub-order,  Ericinece ;  tribe,  Bhodorece. 
By  Gustav  Frank  Kuehnel,  Ph.G. 
From  an  Inaugural  Essay. 
This  plant  is  indigenous  to  the  United  States  from  Maine  to  Ohio, 
but  chiefly  in  the  mountainous  parts  of  Pennsylvania,  and  southward 
along  shaded  water  courses  in  damp,  deep  woods;  it  is  a  shrub  or  tree, 
6  to  20  feet  high,  with  handsome  flowers,  the  corolla  being  bell-shaped, 
an  inch  broad,  of  a  pale  rose  color,  or  nearly  white,  greenish  in  the 
throat  on  the  upper  side,  and  yellow  or  reddish  spotted.  The  leaves 
are  from  4  to  10  inches  long,  evergreen,  coriaceous,  alternate,  elliptical 
oblong,  or  lance  oblong,  acute,  narrowed  towards  the  base,  very  smooth, 
unequal  at  the  base,  and  with  an  entire,  somewhat  revolute,  margin, 
near  which  the  anastomosing  veins  form  one  or  two  distinct  wavy 
lines.  A  quantity  of  the  leaves  were  collected  for  me  about  the  mid- 
dle of  August  by  Mr.  Henry  C.  C.  Maisch,  a  fellow-student  and  class- 
mate, in  the  neighborhood  of  Cresson  Springs,  Pa.  These  were  care- 
fully dried,  remote  from  heat  and  direct  rays  of  the  sun,  powdered, 
and  subjected  to  an  examination  which  resulted  in  isolating  the  three 
constituents,  according  to  Prof.  Maisch,  apparently  characteristic  for 
coriaceous  leaves  of  ericaceous  plants,  viz.,  arbutin,  ericolin  and  ursone ; 
besides  these  principles,  tannin,  gallic  acid,  resin,  wax,  albumen,  color- 
ing matter  and  a  trace  of  volatile  oil  were  observed. 
A  portion  of  the  powdered  drug  was  subjected  successively  to  the 
treatment  of  petroleum  spirit,  ether  and  alcohol,  according  to  Dragen- 
dorfl. 
The  solution  in  petroleum  spirit  was  evaporated  at  the  ordinary 
temperature ;  towards  the  close  of  the  operation  a  pungent,  peculiar 
odor,  slightly  irritating,  was  perceptible,  possibly  due  to  a  little  vola- 
tile oil ;  a  soft,  semi-solid,  waxy  mass,  of  a  peculiar  resinous  odor, 
was  left  as  a  residue. 
The  etherial  liquid  was  allowed  to  spontaneously  evaporate  at  the 
ordinary  temperature,  and  the  resulting  residue  was  treated  with  water 
and  filtered.  The  filtrate  was  found  to  contain  gallic  acid,  by  treating 
with  acetic  ether,  separating  and  evaporating,  when  crystals  were  left 
which  in  solution  darkened  upon  addition  of  solution  of  iron  salt,  but 
on  being  heated  the  color  vanished ;  the  liquid  gave  no  precipitate 
with  solution  of  gelatin. 
