Am'sipt.a56arm'}     Formaldehyde  and  its  Condensation.  441 
syrup,  dissolved  in  alcohol  and  treated  with  ether,  which  precipitates 
the  sugar  as  a  tenacious  mass.  The  crude  product  was  purified  by 
partial  precipitation.  When  dried  at  90°,  it  forms  a  gum-like  mass, 
and  could  not  be  obtained  in  the  crystalline  form.  It  has  an  intensely 
sweet  taste,  like  that  of  cane-sugar  syrup,  which  it  generally  resem- 
bles in  its  behavior,  as  for  instance  towards  phenylhydrazine.  It  is 
sparingly  soluble  in  alcohol,  insoluble  in  ether.  When  heated  at 
119— 120°,  it  gives  up  the  elements  of  water,  and  yields  a  compound 
of  the  formula  C6H10O5,  having  an  intensely  bitter  taste.  Formose 
gradually  loses  its  reducing  power  for  Fehling's  solution,  when 
digested  with  a  2  per  cent,  solution  of  sulphuric  acid ;  warm  strong 
hydrochloric  acid  decomposes  it  with  formation  of  humous  sub- 
stances. It  is  more  readily  decomposed  by  alkalis  than  dextrose.  It 
reduces  an  alkaline  solution  of  potassium  ferricyanide  to  ferrocyanide, 
and  precipitates  metals,  such  as  gold,  palladium,  etc.,  from  solutions 
of  their  salts.  Like  dextrose  and  levulose,  it  gives  a  red  coloration 
when  warmed  with  an  alkaline  picric  acid  solution  ;  it  also  decolorizes 
a  solution  of  sodium  sulphindigotate  in  presence  of  sodium  carbonate. 
Other  color  reactions  are  described.  Formose  is  quickly  acted  on  by 
bromine,  yielding  oxalic  and  trihydroxybutyric  acids.  The  action  of 
nitric  acid  and  of  nascent  hydrogen  was  also  tried,  but  without  any 
very  definite  results. 
Yeast  was  found  to  have  no  action  on  formose  carefully  freed  from 
formic  acid.  When  a  5  per  cent,  solution  is  kept  for  three  weeks 
with  5  c.c.  of  hay  water,  1  per  cent,  of  peptone,  precipitated  calcium 
carbonate,  and  O'l  per  cent,  of  hydrogen  dipotassium  phosphate  at 
the  ordinary  temperature,  a  small  quantity  of  lactic  and  less  succinic 
acid  are  formed.  Mould  spores  act  on  formose  with  separation  of  a 
substance,  which  rotated  polarized  light  5°  to  the  right. 
Compounds  of  formose  with  baryta,  sodium  chloride,  etc.,  were  pre- 
pared. The  phenyldrazine-compound,  C18H22N403,  formed  by  the 
union  of  phenylhydrazine  (2  mols.)  and  formose  (1  mol.)  with  elimi- 
nation of  3  mols.  OH2,  is  described.  Formose  resembles  the  glucoses 
and  differs  essentially  from  Carius'  phenose  (Annalen,  cxxxvi,  324), 
which  is  possibly  an  aromatic  compound. 
The  substance  obtained  by  Butlerow  by  the  addition  of  lime-water 
to  a  boiling  solution  of  "  trihydroxymethylene,"  and  described  by  him 
as  methylenitan  with  the  provisional  formula  C7H14Ofi,  is  also  formed 
by  the  action  of  lime  at  70-90°  on  formose;  it  is  a  mixture  consist- 
