558 
MANNITE  FROM  THE  LEPTANDRA  VIRGINICA. 
action,  save  the  extraction  of  a  portion  of  coloring  matter  from  it. 
Boiling  alcohol  dissolved  it  completely,  from  which  it  separated 
upon  cooling,  in  a  crystalline  spongy  mass  of  a  yellow  color. 
The  whole  quantity  I  had  (some  two  ounces)  was  then  dis- 
solved in  boiling  alcohol  along  with  animal  charcoal.  The  so- 
lution passed  through  the  filter  perfectly  free  from  color,  and 
the  whole  bulk  of  the  filtrate  upon  cooling  set  in  a  mass  of 
crystals,  which  were  left  to  dry  in  the  dish  so  as  not  to  disturb 
or  break  the  soft  delicate  crystals.  In  crystalline  form  they 
were  identical  with  those  of  mannite,  and  like  it,  soluble  in  boil- 
ing alcohol,  from  which  it  separated  upon  cooling ;  had  a  pecu- 
liar sweet  taste,  and  the  watery  solution,  with  the  addition  of 
yeast,  after  standing  in  a  warm  place  for  some  days,  exhibited 
no  signs  of  fermentation.  That  this  substance  is  mannite  I 
think  does  not  admit  of  a  doubt,  as  it  has  its  crystalline  form, 
sweet  taste,  soluble  in  water  and  in  boiling  alcohol,  from  which 
it  is  deposited  again  upon  cooling,  and  does  not  undergo  fer- 
mentation when  its  solution,  mixed  with  yeast,  is  exposed  to  its 
fermenting  action. 
The  occurrence  of  mannite  in  vegetable  infusions,  or  the  ex- 
pressed juices  of  roots,  etc.,  has  been  before  observed,  particu- 
larly in  that  of  the  dandelion,  by  Messrs.  Smith,  of  Edinburgh, 
and  demonstrated  by  them  not  to  exist  in  the  original  solution, 
but  to  be  the  result  of  a  fermentive  action  upon  the  starchy 
portion  of  the  juice,  (a  true  lactic  fermentation,)  as  the  occur- 
rence of  mannite  was  always  accompanied  with  that  of  lactic 
acid.  But  in  the  present  instance,  the  occurrence  of  mannite 
from  an  alcoholic  tincture  of  the  root  must  be  traced  to  a  differ- 
ent source,  as  alcohol  has  no  solvent  action  upon  starch,  or  gum, 
consequently  neither  could  be  present  in  the  watery  solution, 
left  after  evaporating  away  the  alcohol  and  the  addition  of  water 
to  precipitate  the  resin. 
The  only  plausible  supposition  of  the  formation  of  mannite  in 
this  solution  seems  to  me  to  be,  that  the  root  of  the  Leptandra 
must  contain  sugar,  which  was  taken  up  by  the  alcohol  along 
with  extractive  matter,  which  two  substances,  after  the  evapora- 
tion of  the  alcohol  and  precipitation  of  the  resin,  have  been  left 
standing  exposed  for  some  time,  and  have  undergone  a  fermen- 
tation resulting  in  the  production  of  mannite  and  lactic  acid. — 
(  (Jin  cin n  ati)  Druggist. 
