.Am.  Jour.  Pliarm.  \ 
Sept.,  1881.  i 
Inulin. 
469 
C19H23NO3,  diifers  by  two  atoms  of  hydrogen  more  from  tliebaine,  of 
which  Claude  Bernard  demonstrated  the  tetanizing  power. — Pharim. 
Jour,  and  Trans.,  July  16,  1881 ;  Coniptcs  Rendus,  vol.  xcii,  May 
16,1881. 
INULIN. 
By  H.  Ktliani. 
The  author  at  the  outset  alludes  to  the  discordant  results  of  former 
researches  on  inulin  and  to  the  necessity  of  a  fresh  study  of  its  prop- 
erties and  chemical  relations.  In  order  to  prepare  it,  roots  of  the 
Dahlia  variabilis  and  Inula  helenium  were  boiled  with  water  in  the 
presence  of  sodium  carbonate.  The  liquid  obtained  was  cooled  by 
a  freezing  mixture,  and  the  separated  precipitate  was  dissolved  in  hot 
water,  filtered,  and  again  exposed  to  a  freezing  mixture.  After 
repeating  this  process  three  or  four  times,  the  inulin  is  obtained  per- 
fectly white  and  is  subsequently  purified  from  levulose  by  absolute 
alcohol,  and  finally  dried  over  sulphuric  acid. 
Inulin  obtained  in  this  way  is  a  white  powder  resembling  starch ; 
by  slow  evaporation  of  an  aqueous  solution  it  forms  "  crystal  spheres,'^ 
as  observed  by  Sachs  and  Prantl  Jahresb.,''  1870,  849).  It  is  inso- 
luble in  absolute  alcohol,  sparingly  soluble  in  dilute  alcohol  and  cold 
water,  but  very  soluble  in  hot  water.  The  author  has  confirmed  the 
formation  of  a  gum-like  and  horny  modification  of  inulin ;  the  latter 
the  author  considers  to  be  a  highly  hydrated  inulin,  which  is  con- 
verted into  solid  lumps  of  inulin  in  the  same  way  that  ferric  hydrate 
and  silicic  acid  are  converted  into  their  corresponding  anhydrous  oxides. 
Its  specific  gravity  is  1*3491,  and  its  optical  rotatory  power,  as  deter- 
mined with  a  Wild's  polaristrobrometer  =  34*6  to  36'4,  gives 
results  agreeing  with  those  of  Lescoeur  and  Morelle  (^'Jour.  Chem.  Soc,,'' 
1878,  970).  The  author  assigns  to  inulin  the  composition  0361162^^31 
(=6CgH^o05  +  Il20) ;  he  has  also  confirmed  the  observations  of  others 
that  inulin,  when  heated  with  water  in  sealed  tubes  at  100°,  is  con- 
verted into  a  sugar  which  resembles  levulose  in  chemical  and  physical 
properties.  When  oxidized  with  dilute  nitric  acid,  inulin  yields  for- 
mic, oxalic,  racemic,  glycollic  and  probably  glyoxylic  acids.  The 
.author  finds  that  glycollic  and  saccharic  acids  alone  are  formed  when 
dextrin  is  oxidized  with  dilute  nitric  acid. 
Inulin  is  slowly  oxidized  by  long  contact  with  bromine  in  sealed 
