522 
Poison  Sumac. 
f  Am.  Jour.  Pbarm. 
I  November,.  1907. 
Pfaff38  states  that  he  found  3  6  per  cent,  of  crude  "  toxicodendrol  " 
in  the  fruit  of  Rhus  toxicodendron,  but  does  not  give  the  amount  in 
Rhus  vcrnix,  though  we  are  led  to  believe  that  he  found  it  in  the 
fruit  of  this  species.  He  says  :  "  It  (toxicodendrol)  was  found  in  all 
parts  of  the  plant — stems,  branches,  roots,  leaves  and  fruits — its 
amount,  however,  varying,  the  fruit  and  leaves  containing  most. 
The  oil  was  found  in  Rhus  toxicodendron  as  well  as  Rhus  venenata  " 
[Rhus  vernix).  For  the  extraction  of  his  "  toxicodendrol  "  we  be- 
lieve that  Pfaff  must  have  employed  fruit  which  had  been  collected 
in  a  green  state  or  contaminated  with  other  parts  of  the  plant,  for 
we  have  repeatedly  examined  the  fully  ripened  fruit  of  both  these 
species  and  have  been  unable  to  find  any  traces  of  poison  in  either. 
As  before  stated,  we  have  found  19-21  per  cent,  of  fat  in  the  fully 
ripened  fruit  of  Rhus  vernixy  and  from  the  mature  fruit  of  Rhus  radicans 
(deprived  of  their  pericarps)  we  have  obtained  33-4  per  cent,  of  a 
greenish-white,  solid  fat,  which  closely  resembles  that  from  sumac 
fruit,  but  is  slightly  softer  and  less  brittle.  Its  specific  gravity  is 
0-9577  at  250  C./250  C. ;  saponification  value,  238-55  mg.  KOH  ; 
and  its  iodine  absorption  number  30-119.  When  purified  by  one 
crystallization  from  hot  alcohol  it  is  a  hard,  brittle,  white,  solid  fat, 
similar  in  appearance  to  that  obtained  by  similar  treatment  from  the 
crude  fat  of  the  sumac,  although  slightly  softer  and  less  brittle. 
The  purified  fat  melts  at  420  to  42  5  0  C.  (uncorrected).  Meyer39  states 
that  the  wax  from  Rhus  toxicodendron  {R.  radicans}  melts  under  all 
conditions  at  420  C,  and  is,  therefore,  probably  a  pure  substance. 
We  have  found  that  the  crude  fat  as  extracted  from  the  fruit  is  not 
a  pure  individual  substance,  since  a  single  crystallization  from  alcohol 
not  only  yields  a  product  that  is  much  whiter,  harder,  and  more 
brittle  than  the  crude  fat,  but  lowers  its  iodine  number  from  30-1  to 
15-8.  Probably  its  iodine  number  could  be  lowered  still  further  by 
repeated  crystallizations.* 
38  Jour.  Exp.  Med.,  2,  188. 
39  Arch.  Pharm.,  25,  120. 
*  Read  before  the  Scientific  Section  of  the  American  Pharmaceutical  Asso- 
ciation, September,  1907. 
