508 
Poison  Sumac. 
(Am.  Jour.  Pharm. 
I  November.  1907. 
have  found  the  symptoms  of  poisoning  by  Rhus  vernix  similar  in 
all  respects  to  those  caused  by  Rhus  vernicifera. 
SEPARATION  OF  THE  RESINS  FROM  THE  LAC. 
A  large  sample  of  the  strained  lac  was  agitated  with  three  vol- 
umes  of  95  per  cent,  alcohol  and  poured  on  a  filter.  A  brownish 
residue  remained  undissolved,  which  became  darker  on  further  expo- 
sure to  the  air.  This  residue  was  again  shaken  with  alcohol  and 
the  process  repeated  until  the  filtrate  became  colorless.  The  insol- 
uble portion  was  then  washed  with  ether  and  dried  in  the  air.  It 
was  a  reddish. brown  powder,  only  partially  soluble  in  water.  The 
alcoholic  filtrate  was  evaporated  under  reduced  pressure.  It  gave  a 
dark,  amber-red,  oily  liquid.  These  residues  were  reserved  for  fur- 
ther study. 
To  determine  the  composition  of  the  lac  by  solubility,  we  employed 
a  modification  of  the  method  used  by  Ishimatsu  for  Japanese  lac. 
The  method  used  is  as  follows  :  Five  grammes  of  the  strained  lac 
were  transferred  from  a  weighing  bottle  to  a  mortar,  triturated  with 
95  per  cent,  alcohol,  allowed  to  settle  five  minutes,  and  the  super- 
natant solution  decanted  through  a  tared  Gooch  crucible  containing 
a  mat  of  asbestos  at  least  1-5  centimeter  in  thickness.  More  alcohol 
was  then  added  to  the  residue  in  the  mortar  and  the  trituration  and 
decantation  repeated.  The  insoluble  residue  was  then  transferred  to 
the  Gooch,  washed  twice  with  strong  alcohol,  once  with  ether,  dried 
at  ioo°  C.  and  weighed.  The  percentage  insoluble  in  alcohol  was 
calculated  from  this.  To  determine  the  portion  insoluble  in  water 
the  dried  residue  in  the  Gooch  crucibles,  together  with  the  upper 
layers  of  asbestos,  was  transferred  to  a  mortar  and  repeatedly 
triturated  with  hot  water.  The  mixture  was  passed  through  the 
Gooch  in  which  the  alcoholic-insoluble  residue  was  first  weighed,  the 
residue  washed  with  hot  water,  dried  at  ioo°  and  weighed.  The 
residual  weight  represents  the  portion  insoluble  in  water  (or  alcohol) 
and  the  loss  in  weight  the  portion  soluble  in  water.  The  deter- 
minations were  made  in  duplicate  and  in  triplicate,  the  results 
usually  being  very  concordant.  From  the  tabulated  results  given 
below  it  will  be  seen  that  the  composition  seems  to  vary  somewhat 
in  different  months  and  also  from  different  parts  of  the  tree,  though 
the  number  of  determinations  made  was  insufficient  to  establish  the 
