512 
Poison  Sumac. 
f  Am.  Jour.  Pharm. 
I  November,  1907. 
mass,  having  the  odor  of  the  crude  resin,  was  obtained.  This  sub- 
stance, which  amounted  to  15-5  per  cent,  of  the  original,  had  a 
sp.  gr.  of  1-05167  at  250  C./250  C.  It  slowly  hardened  at  ordinary 
temperature  and  was  not  poisonous.  By  heating  for  several  hours 
at  iio°  C.  it  yielded  a  solid,  dark-brown  mass,  which  was  insoluble 
in  all  ordinary  solvents  and  was  exceedingly  difficult  to  pulverize. 
Analysis  of  the  dried  product  gave  the  following  results : 
I. 
0*3165  gramme  gave  0*2121  gramme  H20  and  0*8683  gramme  C02. 
II. 
0*3382  gramme  gave  0*2326  gramme  H20  and  0*9295  gramme  C02. 
I. 
0*5026  gramme  gave  9*6  c.c.  N  at  230  C.  and  739  mm. 
II. 
0*5014  gramme  gave  9*5  c.c.  N  at  230  C.  and  736  mm. 
I.  II.  Mean. 
Per  Cent.  Per  Cent.  Per  Cent. 
Hydrogen  7*527  7*693  7*610 
Carbon  75*  129  74*955  75 '042 
Nitrogen  2*092  2*067  2*079 
The  undried  resin  was  soluble  in  alcohol,  chloroform,  glacial 
acetic  acid  and  partially  soluble  in  ether  and  methyl  alcohol ;  it  was 
insoluble  in  glycerol,  water  or  petroleum  benzin.  When  boiled  with 
alcoholic  KOH,  the  undried  resin  yielded  a  brown-black  soap,  soluble 
in  water,  and  a  brownish-black  insoluble  substance,  but  no  glycerol. 
Aqueous  solutions  of  this  soap  lather  considerably  when  shaken,  but 
have  no  detergent  properties.  The  properties  of  the  insoluble  sub- 
stance are  similar  to  those  of  "  oxyurushin  "  obtained  by  Tschirch 
and  Stevens28  from  Japanese  lac.  Many  attempts  were  made  to 
determine  its  saponification  number,  but,  owing  to  the  great  diffi- 
culty of  determining  the  end  reaction  with  indicators  in  the  opaque, 
red-brown,  soap  solution,  no  satisfactory  results  were  obtained. 
Numbers  were  found  varying  from  286*7  to  344'2  mg-  °f  KOH. 
Litmus,  phenolphthalein,  methyl  orange  and  alkali  blue  were  all 
tried,  both  as  external  and  internal  indicators,  but  the  exact  point 
of  neutrality  could  not  be  determined.  The  indirect  method  of 
Mclllhiney29  was  also  tried  but  without  success,  as  the  resin  soap  is 
not  completely  soluble  in  alcohol.    This  benzin-insoluble  resin  could 
28  Arch.  Pharm.,  243,  523. 
29  Jour.  Amer.  Chem.  Soc,  16,  408. 
