■^™jun 6^1882.^^'}   Analytical  Researches  and  Investigations.  289 
yellow^  then  brown,  after  a  short  time  reddish-brown,  and  finally 
changing  to  a  dark  blood-red  color.  The  edge  of  the  liquor  becomes 
bounded  by  a  narrow  blue  ring,  which,  when  stirred  by  means  of  a 
glass  rod,  shows  blue  stripes.  The  tanacetum-tannic  acid  corresponds 
to  the  formula  C23H29O31 ;  on  boiling  with  dilute  hydrochloric  acid  it 
appears  to  become  decomposed  into  sugar  and  catechin. — Ibid. ;  from 
Pharm.  Ztschr.f.  Russ.,  21,  pp.  141,  169  and  193. 
On  Galactin.  By  A.  Muntz. — The  author  has  extracted  from  legu- 
minous seeds  a  substance  to  which  the  name  of  galactin  is  applied,  and 
which  is  considered  as  a  definite  chemical  principle.  It  is  obtained  by 
treating  powdered  lucerne  seeds  with  water  containing  a  little  neutral 
acetate  of  lead.  To  the  liquid  thus  obtained  a  slight  excess  of  oxalic 
acid  is  added,  which  precipitates  the  lead  and  the  lime,  after  which  to 
the  clear  liquid  one  and  a  half  times  its  volume  of  92  per  cent,  alcohol 
is  added.  A  white  mass  is  thus  obtained  which  remains  attached  to  the 
rod  with  which  the  liquid  is  stirred.  The  mass  is  expressed,  washed 
with  water  containing  a  considerable  amount  of  alcohol,  then  re-dis- 
solved in  water  and  precipitated  a  second  time  by  alcohol. 
When  thus  prepared,  and  dried  by  exposure  to  the  air,  it  j^resents 
the  form  of  white,  translucid  nodules,  containing  a  small  quantity  of 
mineral  matter.    It  swells  in  water,  then  dissolves  slowly,  similarly 
to  gum  arable.    The  solution  is  viscid,  but  limpid  ;  it  is  not  precij^i- 
\  tated  by  the  neutral,  but  by  basic  acetate  of  lead,  and  shows  the  same 
deportment  to  metallic  compounds  as  gum  arable.    Its  composition  is 
that  of  the  latter;  CgHjoOg ;  it  is  dextrogyrate,  and  its  rotatory  j^ower 
with  sodium  light  is  +84*6°.    When  treated  with  nitric  acid  it 
yields  a  large  amount  of  mucic  acid.    When  treated  at  the  tempera- 
ture of  100°C.  with  dilute  mineral  acids,  it  is  slowly  transformed  into 
saccharine  matters,  which,  when  brought  to  the  consistence  of  a  syrup^ 
yield  hard,  brilliant  crystals,  readily  obtained  pure  by  repeated  crys- 
tallization from  alcohol ;  there  then  remains  also  an  uncrystallizable 
sugar.    The  crystals  are  but  sj^aringly  soluble  in  cold  alcohol,  but  dis- 
solve in  boiling  alcohol,  from  which  they  are  deposited  in  the  form  of 
a  crystalline  crust.    Their  taste  is  slightly  saccharine  •  but  they  are 
very  different  from  arabinose,  a  sugar  which  is  generally  obtained  by 
treating  gum  with  dilute  acids.    In  all  their  properties  they  approach 
•^morc  closely  to  the  a  galactose  of  Fudakowsky,  which  is  obtained  by 
the  decom|)osition  of  sugar  of  milk.    A  comparison  with  galactose  has 
confirmed  the  identity  of  the  two  produ(;ts,  they  having  the  same  rota- 
19 
