Oil  of  Sandalwood. 
Am.  Jour.  Pharm. 
January,  1914. 
a  statement  published  last  October  in  the  same  journal,  to  the 
effect  that  the  disease  still  continues  with  dire  results,  and  that 
in  two  districts  alone  some  70,000  sandal  trees  had  to  be  uprooted. 
In  order  to  obtain  an  idea  of  the  probable  cause  of  this  disease 
it  is  necessary  to  pay  some  attention  to  the  life  history  of  the  plant, 
so  far  as  this  is  known.  As  already  mentioned,  the  sandal  tree 
is  a  root  parasite,  obtaining  its  food  by  means  of  suckers,  which  it 
attaches  to  the  roots  of  other  trees.  It  has  been  ascertained  by 
Rama  Rao  that  there  are  at  least  144  species  of  plants  which  the 
sandal  tree  attacks  in  this  way,  as  proved  by  experiment  with  sandal- 
wood seedlings,  and  he  gives  a  list  of  252  plants  which  are  found 
growing  near  or  with  the  sandal  tree,  but  are  as  yet  not  known  to  be 
utilized  as  a  source  of  food  by  this  tree.  It  does  not  appear  to  be 
equally  nourished  by  all  of  its  host  plants,  and  the  condition  of  the 
tree  depends  upon  the  vigorous  and  healthy  state  of  its  host.  Thus 
it  is  known  that  a  plant  on  which  it  will  thrive  in  one  district  fails 
to  keep  it  in  a  healthy  state  in  another,  where  the  conditions  are 
unsuitable  to  the  healthy  growth  of  the  host  plant.  This  require- 
ment of  the  sandalwood  tree  is  well  shown  by  an  observation 
recorded  in  the  Indian  Forester,  (xxxl,  p.  191),  that  when  a  trunk 
of  Heptapleurum  was  cut  down,  the  sandal  plant  attached  to  its 
roots  began  to  wither,  but  when  new  shoots  formed  on  it  the  sandal 
plant  began  to  revive.  The  sandalwood  tree  sends  out  roots  for 
150  feet  or  more,  and  therefore  requires  a  comparatively  loose 
and  well-drained  soil  which  the  roots  can  easily  penetrate  and 
spread  in.  In  a  natural  state  it  flourishes  at  an  altitude  of  1500 
to  4000  ft.,  the  best  yield  of  oil  being  obtained  from  trees  growing 
between  2000  to  3500  ft.,  on  loose  volcanic  soil  mixed  with  rocks, 
and  preferably  ferruginous  in  character.  It  requires  to  be  shaded 
by  thickets  above  which  it  can  form  a  head  of  leafy  branches. 
Although  in  rich  soil  it  grows  more  luxuriantly,  less  scented 
wood  is  formed,  although,  as  the  tree  furnishes  more  wood,  the 
proportion  is  about  the  same.  It  is  considered  that  the  richness  of 
the  wood  in  oil  depends  more  upon  elevation  and  exposure,  since, 
although  the  tree  grows  luxuriantly  at  700  ft.,  the  wood  is  said  to  be 
totally  devoid  of  scent  at  that  altitude  (Indian  Forester,  xxvl, 
pp.  1-50,  1900). 
The  experiments  made  by  Rama  Rao  indicate  that  the  physical 
conditions  of  soil  and  drainage  affect  the  development  of  the  root- 
branching  system.    The  soil  needs  to  be  well  drained,  as  the  seed 
