32  Recent  Work  in  the  Sugar  Group.      {Am jJa°nu,ri£?arm- 
(2)  The  Valley,  Blue  Mountains,  N.S.W.,  collected  in  April, 
height  80-150  feet,  diam.  1-2  feet. 
The  description  of  No.  1  will  apply  here  with  the  following  excep- 
tions :  In  bulk  it  is  hardly  so  red  as  No.  1 /while  its  powder  is  of  a 
dark  buff  color.  To  cold  water  it  behaves  in  the  same  way  as  No. 
I  ;  it  is,  however,  less  turbid  and  lighter  in  color.  With  alcohol  it 
yields  a  pale  orange-brown  solution. 
RECENT  WORK  IN  THE  SUGAR  GROUP.1 
The  carbohydrates  of  the  sugar  group  and  the  compounds  related 
to  them  have  formed  the  subject  of  a  great  deal  of  the  recent  work 
of  Professor  Emil  Fischer  and  many  other  workers,  and  in  view  of 
the  frequent  publication  of  fresh  results,  it  is  desirable  to  give  a 
concise  account  of  the  more  important  portions  of  the  work  that 
has  hitherto  been  done. 
In  the  first  place,  the  nomenclature  of  the  group,  which  was 
before  obscure  and  unsystematic,  has  been  greatly  altered  and 
extended.  Sugars  which  are  simple  derivatives  of  hydrocarbons 
have  names  ending  in  -ose,  the  number  of  carbon  atoms  in  the 
molecule  being  indicated  by  the  prefix,  as  pentose,  C5H10O5,  hexose, 
C6H1206,  etc.  ;  the  source  of  the  sugar  may  be  indicated  by  a  further 
prefix,  as  glucoheptose,  manno-nonose.  Sugars  which  are  formed 
by  the  combination  of  two  or  more  molecules  of  a  simpler  sugar 
have  names  with  the  terminations  -biose,  -triose,  etc.,  to  indicate 
the  number  of  molecules  so  combined,  while  the  prefix  shows  the 
sugar  from  which  they  are  derived,  as  lactobiose,  hexatriose,  etc. 
The  names  dextrose  and  laevulose,  for  the  two  sugars  of  the  formula 
C6H1(,06,  which  are  formed  by  inversion  of  cane-sugar,  have  been 
abandoned,  since  these  substances  are  not  merely  optically,  but 
structurally  different,  and  each  can  exist  in  a  dextro-rotatory  and  a 
lsevo-rotatory  form  ;  they  are  replaced  by  the  terms  glucose  and 
fructose,  respectively.  Glucose  is  an  alcohol-aldehyde,  represented 
by  the  formula  CH^H^CHOH^CHO,  and  is  the  type  of  a  number 
of  sugars  containing  the  aldehyde  group — CHO,  and  hence  called 
aldoses;  while  fructose,  CH2OH(CHOH)3COCH2OH,  is  the  type  of 
those  containing  the  ketone  group  — CO — ,  and  therefore  called 
ketoses. 
1  Pharmaceutical  Journal  and  Transactions,  Oct.  29,  1S92,  p.  34S. 
