Am.  Jour  Pharm.  )  CciVamclizatioil    ill    Rkws's  Test. 
April,  1910.  J 
157 
hydroxide  lias  exactly  the, same  action  as  potassium  hydroxide. 
Milk-sugar  is  also  strongly  browned  by  the  alkalies,  and  decomposed 
with  the  formation  of  lactic  acid.10 
The  exact  mechanism  of  these  changes  has  not  been  worked 
out.  but  Gaud  17  has  thrown  light  on  parts  of  the  process.  He  was 
able  to  establish  the  formation  of  lactic  acid,  oxybenzoic  acid,  oxalic 
acid,  and  two  isomeric  dioxyphenylpropionic  acids,  also  "  melas- 
sique  "  acid  and  "  glucique  "  acid  constituting  the  greater  part  of 
the  "resin"  formed  when  copper  oxide  is  also  present  with  the 
alkali.  These  two  complex  acids  had  previously  been  described  by 
Mulder  in  a  paper  entitled  "  Researches  on  Bodies  of  a  Humus 
Nature. "  ]S  According  to  Gaud,  some  of  the  glucose  undergoes  a 
dehydration  and  condensation  under  the  action  of  the  alkali  with 
the  formation  of  the  complex  "  glucique  "  acid. 
2C6H12Ob  =  3H20-C12H1809 
This  acid  is  unstable  and  breaks  down  into  pyrocatechinol  and 
Sfluconic  acid : 
CioHlsO,j 
HC 
HC 
CH 
CH 
COH 
COH 
CH2OH 
CHOH 
CHOH 
I 
CHOH 
CHOH 
COOH 
The  gluconic  acid  separates  into  glyceric  acid  and  lactic  acid : 
CHX>H 
CHoOH 
CHOH 
I 
CHOH 
I 
CHOH 
I 
CHOH 
I 
COOH 
> 
CHOH 
COOH 
CH, 
I 
CHOH 
I 
COOH 
3  Nencki  and  Sieber,  Journ.  fur  prak.  Chem.  (2),  24,  498,  1881. 
r.Gaud,  Compt.  rend.,  119,  p.  604,  1894. 
s  Liebig's  Annalen,  36,  p.  243,  1840. 
I 
