500 
Poison  Sumac. 
j  Am.  Jour.  Pharm. 
1  November,  1907. 
greenish-yellow  flowers,  which  appear  late  in  June  or  early  July,  are 
borne  on  long,  loose  panicles  from  the  axils  of  the  leaves.  The 
sterile  and  the  fertile  flowers  are  borne  on  separate  plants.  The 
fruit  is  a  drupe,  4  to  6  mm.  in  diameter,  unequal  sided  and  some- 
what flattened.  At  maturity  in  September  the  outer  coat  is  thin, 
more  or  less  striated,  grayish-white  and  lustrous;  the  stone  is  pale 
yellow  in  color  and  noticeably  grooved. 
The  fruit  remains  on  the  tree  until  spring.  On  wounding  the 
trees,  a  pale  cream-colored,  thick,  poisonous  juice  exudes  in  abund- 
ance.   This  begins  to  darken  at  once  and  finally  becomes  black. 
Very  little  work  has  been  done  upon  the  chemistry  of  the  poison 
of  Rhus  vernix.  A  number  of  chemists,  however,  have  worked 
upon  the  poisonous  constituents  of  Japanese  lac  {Rhus  vermciferd) 
and  of  poison  ivy  {Rhus  radicans),  and,  as  clinical  observation  has 
established  that  the  dermatitis  caused  by  any  one  of  the  venomous 
species  of  Rhus  is  similar  in  appearance  to  that  from  the  others,  it 
is  now  generally  believed  that  the  poisons  from  all  these  plants  are 
identical.  We  give  below  a  brief  digest  of  the  results  that  have 
been  obtained  by  previous  investigations  of  the  constituents  of  these 
plants. 
■  In  1 8 1 5  Dr.  Bigelow8  experimented  upon  the  juice  of  Rhus  vernix, 
and  showed  that  it  possessed  varnish-forming  properties  similar  to 
the  juice  from  Japanese  sumac.    He  says  : 
"  A  quantity  of  the  juice  was  boiled  alone,  until  nearly  all  the 
volatile  oil  had  escaped,  and  the  remainder  was  reduced  almost  to 
the  state  of  a  resin.  In  this  state  it  was  applied  while  warm  to 
several  substances,  which,  after  cooling,  exhibited  the  most  brilliant, 
glossy,  jet  black  surfaces.  The  coating  appeared  very  durable  and 
firm,  and  was  not  affected  by  moisture.  It  was  elastic  and  perfectly 
opaque,  and  seemed  calculated  to  answer  the  purposes  of  both  paint 
and  varnish."  Dr.  Bigelow  seems  to  have  done  no  further  work 
upon  the  chemistry  of  the  juice. 
In  1859  J:  Khittel9  worked  upon  poison  ivy.  He  attributed  the 
poisonous  properties  of  this  plant  to  a  volatile  alkaloid.  He  did  not 
succeed  in  isolating  any  alkaloids,  however,  so  that  his  results  were 
of  but  little  value. 
8  ''Medical  Botany,"  J.  Bigelow,  I,  101-102. 
9  Wittstein's  Vierteljahresschrift  fiir  praktische  Pharmacie,  7,  348-59  ;  abstract 
Am.  J.  Pharm.,  1858,  542-4. 
