AUSTRALIAN  MEDICINAL  PLANTS. 
73 
ture  in  the  vegetation.  Our  Alps,  however,  enrich  us  also  with 
a  thick-rooted  gentian  (6r.  Diemensis,  Griesebach),  certainly  as 
valuable  as  the  officinal  Gentiana  lutea;  and  in  the  spring  Subcea 
ovata,  R.  Br.,  and  S.  albidiflora,  F.  Mull.,  might  also  be  collected 
on  account  of  their  bitterness.  The  bark  of  the  Australian  sassa- 
fras tree  (Atherospermum  moschatum,  Forst.)  has  already  ob- 
tained some  celebrity  as  a  substitute  for  tea.  Administered  in  a 
greater  degree  of  concentration  it  is  diaphoretic  as  well  as  diuretic, 
and  has  for  this  reason  already  been  practically  introduced  into 
medicine  by  one  of  our  eminent  physicians.  Isotoma  axillaris, 
Lindl.,  surpasses  all  other  indigenous  Lobeliacece  in  its  intense 
acridity,  and  can  be  therefore  only  cautiously  employed  instead 
of  Lobelia  inflata.  The  root  of  Malva  Behriana,  Schlect. 
scarcely  differs  from  that  of  Althcea  officinalis,  and  the  salep  root 
might  be  collected  from  many  Orchidece.  Few  may  be  aware 
the  Cajepet  Oil  of  India  is  obtained  from  trees  very  similar  to 
our  common  Melaleucas ;  and  that  even  from  the  leaves  of  the 
Eucalypti  an  oil  can  be  procured  of  equal  utility.  The  Sandrac, 
exuding  from  Callitris,  or  pine  tree,  the  balsamic  resin  of  the 
grass  trees,  and,  moreover,  the  Eucalyptus  gum,  which  could  be 
gathered  in  boundless  quantities,  and  which  for  its  astringent 
qualities  might,  here  at  least,  supersede  the  use  of  kino  or  cate- 
chu, will  probably  at  a  future  period  form  articles  of  export. 
Several  Acacias  are  of  essential  service,  either  for  their  dura- 
ble wood,  or  for  the  abundance  of  tannin  in  their  bark,  which 
has  rendered  them  already  useful,  or  their  gum  ;  but  the  latter 
is  even  excelled  in  clearness  and  solubility  by  that  obtained 
from  Pittosporum  acacioides,  A.  Cunningh.  This  species,  as 
well  as  many  other  plants  of  the  same  order,  is  distinguished  by 
a  surprising  yet  apparently  harmless  bitterness — a  quality  that 
warrants  our  expecting  considerable  medicinal  power,  and  which 
deserves  so  much  more  attention,  as  till  now  we  know  nothing  of 
the  usefulness  of  the  Pittosporew,  although  this  order  extends 
over  a  greater  part  of  the  eastern  hemisphere. 
The  Australian  manna  consists  in  a  saccharine  secretion,  con- 
densed chiefly  by  the  cicades  from  a  few  species  of  Eucalyptus, 
but  is  chemically  very  differently  constituted  to  the  Ornus  manna, 
and  much  less  aperient.    All  our  splendid  Diosmeo? — a  real  orna- 
