Am.  Jour.  Pharrn.") 
November,  1907.  / 
Poison  Sumac. 
515 
TREATMENT   WITH  LEAD  ACETATE. 
With  an  alcoholic  solution  of  lead  acetate  the  85  per  cent,  alco- 
holic fraction  and  the  benzin-soluble  fraction,  obtained  as  above,  each 
gave  a  flocculent  light-gray  precipitate,  which  darkened  considerably 
on  standing.  By  slightly  modifying  the  method  of  fractional  preci- 
pitation used31  on  the  resins  of  Japanese  lac,  we  have  obtained 
several  fractions  from  the  benzin-soluble  portion  of  the  resin.  All 
these  fractions  were  dark,  brown-red,  poisonous  liquids,  similar  in 
appearance  to  the  original  resin. 
The  method  as  finally  adopted  was  as  follows : 
The  resin  was  dissolved  in  95  per  cent,  alcohol,  and  an  alcoholic 
solution  of  lead  acetate  added  as  long  as  a  precipitate  was  formed. 
The  precipitate  was  filtered  out,  washed  with  alcohol,  suspended  in 
fresh  alcohol  and  decomposed  by  H2S04.  The  excess  of  acid  was 
removed  by  lead  carbonate  and  the  filtrate  evaporated.  The  alco- 
holic filtrate  from  the  first  precipitate  was  treated  with  sulphuric 
acid,  then  with  lead  carbonate,  filtered,  evaporated  to  remove  alcohol 
and  shaken  out  with  ether.  Upon  evaporating  the  ether,  a  dark  red- 
brown  residue  was  obtained,  which,  when  dissolved,  in  alcohol,  was 
readily  precipitated  by  alcoholic  lead  acetate  solution.  This  preci- 
pitate was  treated  like  the  first,  and  this  process  was  repeated  until 
no  appreciable  precipitate  could  be  obtained  with  lead  acetate  solu- 
tion. As  these  fractions  were  all  so  similar  in  appearance  and  prop- 
erties, we  believe  that  no  actual  separation  was  accomplished. 
Syme  and  Acree35  state  that  they  separated  the  poison  of  poison 
ivy  from  impurities  by  extracting  its  impure  lead  compounds  with 
ether  in  a  Soxhlet  apparatus  and  decomposing  the  resultant  soluble 
extract  with  hydrogen  sulphide.  We  have  attempted  to  separate 
the  resins  of  poison  sumac  by  this  method.  Lead  compounds  were 
first  prepared  by  precipitating  an  alcoholic  solution  of  the  benzin- 
soluble,  poisonous  resin  with  a  hydro-alcoholic  solution  of  lead 
acetate.  The  lead  precipitate  was  washed  with  diluted  alcohol  by 
decantation,  thrown  on  a  filter,  further  washed  with  diluted  alcohol 
and  finally  with  hot  water.  It  was  then  placed  in  a  desiccator  over 
sulphuric  acid  until  partially  dried  (twenty-four  hours),  and  extracted 
with  ether  in  a  Soxhlet  apparatus  until  the  solvent  came  over  color- 
3*  "Japanese  Lac."  Dissertation.  A.  B.  Stevens,  p.  20,  1906. 
35  Am.  Chem.  J.,  36,  313-5- 
