ON  SAPONIN. 
349 
of  13  J°,  and  the  same  quantity  of  dextrine  one  of  29 JQ  ;  so  that 
this  sugar  causes  a  greater  rotation  than  any  other  compound  of 
this  group. 
When  this  solution  was  diluted  with  water,  mixed  with  about 
10  per  cent,  of  sulphuric  acid,  and  evaporated  in  the  water-bath 
to  a  little  more  than  its  former  specific  gravity,  its  rotatory 
power  had  undergone  no  change ;  when  mixed  with  potash  and 
oxide  of  copper,  and  heated,  a  sample  gave  no  reduction  of  oxide 
of  copper ;  when  boiled  strongly  for  half  an  hour,  the  rotation 
diminished  by  about  13°,  and  a  sample  mixed  with  potash  and 
sulphate  of  copper,  and  boiled,  effected  a  partial  reduction  of 
the  peroxide  to  protoxide ;  when  boiled  for  several  hours,  so 
much  concentrated  that  a  slight  brown  tint  was  produced,  it  ro- 
tated the  plane  of  polarization  about  10°.  In  these  experiments 
the  samples  taken  out  were  included  in  the  calculation,  and  the 
same  measure  of  fluid  was  always  employed.  This  rotation 
nearly  agrees  with  that  of  a  solution  of  starch-sugar  of  corres- 
ponding strength. 
After  the  sulphuric  acid  had  been  got  rid  of  with  carbonate 
of  baryta,  and  the  filtered,  evaporated  fluid  had  been  set  aside 
for  a  considerable  time,  it  solidified  almost  completely  into  ver- 
rucose  crystals,  the  solution  of  which  was  set  in  fermentation  by 
yeast  as  quickly  as  starch-sugar.  By  long  boiling  with  dilute 
sulphuric  acid,  therefore,  the  sugar  of  ergot  is  converted  into 
starch- sugar. 
As  this  sugar  occurs  in  a  fungus  (^Sxor),  and  belongs  to  the 
group  of  cellulose,  glycose,  and  dulcose,  the  name  my  cose  appears 
to  be  the  most  suitable. — Ohem,  G-az.,  April,  1858,  from  Dericht 
der  AJcad.  der  Wiss.  zu  Berlin,  1857. 
ON  SAPONIN. 
By  M.  Von  Patr. 
In  his  investigation  of  the  seeds  of  the  Horse-chestnut,  Roch- 
leder  found  a  beautifully  crystallized,  colorless,  silvery  substance, 
which  forms  a  principal  constituent  of  the  seeds,  inasmuch  as 
the  other  non-crystalline  constituents  stand  in  a  very  simple  re- 
lation to  it.  This  substance  is  n  conjugate  compound,  giving 
products  of  decomposition  with  alkalies  and  acids,  which  stand 
