Jrxs^so?™ }  The  Resin  of  Leptandra.  49  ^ 
means  of  manipulation,  and  label  the  result  "  Leptandrin."  ^  Thus,  I 
conclude  that:  '"'The  Leptandrin  of  commerce"  varies  much  in 
appearance  and  in  "sensible  properties"  from  the  fact  that  it  is  of  dif- 
ferent degrees  of  fineness  and  of  various  compositions. 
What  is  the  best  process  for  the  preparation  of  the  resin  f  Resin  of 
leptandra  exists  as  such  to  the  extent  of  six  per  cent,  (average  of  3,000 
pounds)  in  vi^ell  dried  root  of  not  less  than  one  year's  age  after  collec- 
tion. It  is  a  recognized  fact,  that  the  yield  of  resin  increases  with  the 
age  and  exposure  of  the  root  after  collection  where  water,  simply,  is 
employed  as  a  precipitant,  and  for  this  reason  the  root  of  two  or  more 
years  of  age  is  desirable.  If  the  powdered  root  be  percolated  with 
alcohol  and  the  percolate  evaporated  to  a  syrupy  consistence,  and  this 
be  poured  into  a  larger  quantity  of  cold  water,  a  semi-solid  substance 
settles.  This,  when  well  washed  and  dried,  is  the  so-called  resin.  If 
the  water  which  was  used  as  a  precipitant  of  the  resin  be  examined  it 
will  be  found  very  bitter,  in  consequence  of  the  presence  of  the  bitter 
principle,  first  noticed  by  Prof.  E.  S.  Wayne  (1856)  and  afterwards  by 
Prof.  F.  F.  Mayer  (1863).  The  latter  gentleman  ascribed  to  it  the 
properties  of  a  glucoside,  and  I  think  his  views  will  be  supported.  If 
five  per  cent,  of  sulphuric  acid  be  mixed  with  the  precipitating  liquor 
after  decantation  from  the  resin,  and  the  mixture  be  permitted  to  stand 
some  weeks,  the  bitterness  disappears,  and  a  quantity  of  resin,  similar 
in  appearance  to  the  original  precipitate,  is  produced.  If,  however,  the 
,  sulphuric  acid  and  the  precipitating  liquid  be  niixed  and  then  boiled  to- 
gether from  thirty  to  sixty  minutes,  the  reduction  takes  place  at  once, 
the  bitterness  disappears  and  resin  results  as  one  product.^ 
This  would  indicate  that  the  bitter  principle  is  a  glucoside,  and  that 
the  resin  is  a  product  of  its  decomposition,  although  I  have  not  experi- 
mented regarding  the  corresponding  production  of  glucose.  That  this 
resin  is  thus  formed  in  a  considerable  amount  may  be  seen  by  specimen 
shown,  which  is  (12  lb.)  the  result  of  a  1,000  pound  batch  of  leptandra. 
In  making  this  lot  the  overlying  liquid  was  simply  decanted  from  the 
precipitate  and  it  may  have  contained  a  small  amount  of  mechanically 
^  Leptandra  is  valued  by  many  for  its  laxative  properties.  The  principle  which 
imparts  to  the  root  this  effect  has  never  been  identified.  L. 
^  This  cannot  be  taken  as  conclusively  pointing  to  the  formation  of  the  resinous 
substance  from  the  bitter  principle.  It  may  be  that  the  resinous  matter  is  held  in  a 
state  of  minute  suspension  by  the  liquid,  or  even  is  in  actual  solution.  The  subse- 
quent manipulation  with  the  acid  solution  may  simply  throw  it  down.  L. 
