334 
Current  Literature. 
Am.  Jour.  Pharm. 
July,  1913. 
reply  to  our  enquiry  from  which  we  have  extracted  the  following 
interesting  information. 
The  Styrax  tree  which  grows  on  Doi  Sootep  and  which  is  fairly 
common  at  600  to  1200  M.  altitude  in  evergreen  jungles  particu- 
larly in  that  type  of  forest  where  Quercus  Junghuhnii  predominates 
and  where  the  soil  consists  of  a  stiff  red  clay  overlain  by  a  thick 
layer  of  humus,  was,  from  flowering  material  only,  believed  to  be 
S.  Benzoin  (Kew  Bull.,  191 1,  p.  409).  The  receipt  of  fruiting 
specimens  showed,  however,  that  it  was  not  Benzoin  but  a  new 
species1  closely  allied  to  S.  suberifolius  and  since  described  as 
S.  benzoides  {Kew  Bull.,  1912,  p.  267).  S.  benzoides,  on  Doi  Soo- 
tep, grows  rapidly  and  attains  a  height  of  12-15  m-  and  a  girth  of 
about  9  dm.  but  most  of  the  trees  are  smaller  though  in  other  parts 
larger  trees  are  reported.  Several  Kamus,  natives  of  the  Luang 
Prabang  region  from  which  most  of  the  gum  comes,  have,  without 
a  leading  question,  identified  the  Doi  Sootep  tree  as  ton  kum  yan, 
kum  yan  being  the  Lao  and  Siamese  name  for  gum  benzoin.  It 
must  be  admitted  that  small  specific  differences  might  not  be  noted 
by  the  natives  though  they  are  often  acute  observers  of  such  points 
particularly  where  economic  plants  are  concerned. 
Dr.  Kerr's  belief  that  this  tree  is  the  source  of  the  Siamese 
gum  benzoin  has  been  confirmed  by  the  receipt  at  Kew  of  a  small 
sample  of  the  gum  collected  from  the  Doi  Sootep  trees  which  in 
smell,  taste  and  fumes  is  identical  with  commercial  Siamese  gum 
benzoin.  Though  the  gum  is  only  casually  collected  in  the  Chieng- 
mai  district  yet  nearly  every  tree  examined  on  Doi  Sootep  had  been 
notched  and  in  some  cases  completely  felled.  In  the  majority 
of  cases  the  cuts  were  very  old  and  on  most  trees  no  gum  at  all 
was  observed  but  on  a  few  there  was  a  small  incrustation  of  gum 
along  the  cuts.  The  largest  piece  of  gum  obtained  weighed  about 
2.5  grammes  and  was  found  in  a  hole  made  by  some  wood-borer. 
It  was  a  homogeneous,  transparent,  pale  amber  piece  with  the  char- 
acteristic odor  of  Siam  benzoin. 
The  principal  method  of  collecting  the  gum  is  by  making  V- 
shaped  incisions  through  the  bark.  The  gum  runs  slowly  into 
bamboo  joints  placed  at  the  bottom  of  the  V,  and  is  not  collected 
until  a  few  weeks  after  the  incision  is  made.  This  is  generally 
done  during  the  hot  season.  Gum  is  also  frequently  found  in  holes 
made  by  wood-borers  and  sometimes  on  or  in  the  ground  at  the 
foot  of  the  trunk.   The  quality  of  the  gum  is  the  same  by  whatever 
