GLEANINGS  FROM  GERMAN   JOURNALS.  403 
RJdnantliin. — Prof.  H.  Ludwig  has  had  occasion  to  examine 
some  rye  bread,  of  a  violet  black  color,  also  the  grain  from  which 
the  flour  had  been  made.  The  latter  contained  97*5  per  ct.  of 
the  fruit  of  cereals,  nearly  all  rye,  the  balance  being  seeds  of 
weeds,  &c.,  among  them  1-415  parts  from  Rhinanthus  alectoro- 
lophus,  Lin.  (^Alect.  Jmsutus,  Reichenbach),  to  the  presence  of 
which  the  color  of  the  bread  was  due,  and  ^om  which  the  chro- 
mogen  was  obtained.  The  crushed  seeds  were  exhausted  with 
boiling  alcohol,  the  solvent  evaporated,  the  oil  removed  by  ether, 
and  the  filtered  aqueous  solution  evaporated  to  a  syrupy  con- 
sistence, from  which  rhinanthin  crystallizes  in  stellate  prisms, 
which  are  to  be  purified  by  recrystallization  from  alcohol.  Its 
aqueous  solution  is  not  afi'ected  by  chlorine,  salts  of  iron,  lead, 
copper  and  silver  (in  the  cold),  but  is  colored  brown  by  mineral 
acids.  Its  alcoholic  solution  heated  with  muriatic  acid  yields  a 
green  blue  coloration  of  such  intensity  that  the  liquid  is  nearly 
black  in  appearance.  It  has  a  bitterish  sweet  taste  and  is  solu- 
ble in  water  and  alcohol.  Its  composition  is  CggH^gO^o.  Boiled 
with  dilute  muriatic  acid,  it  yielded  13'9,  and  in  another  experi- 
ment 26-7  per  cent,  of  dark  brown  floccules,  rhinanthogenin  ; 
composition,  C^Ji2o^8'  filtrate  contained  a  fermentable 
sugar,  of  the  composition  CigHjgO^g.  The  relation  of  the  brown 
product  to  the  intensely  blue  body,  obtained  by  alcohol  and 
muriatic  or  sulphuric  acid,  was  not  established. — Archiv  d. 
PJiarm.  1870,  June,  199-215. 
The  tannin  of  the  European  alder ^  Alnus  glutinosa,  has  been 
examined  by  F.  Dreykorn  and  E.  Reichardt,  who  found  that 
with  sulphuric  acid  it  splits  into  alnic  red  and  sugar ;  fused  with 
hydrate  of  potassa,  phloroglycin,  protocatechuic  and  acetic  acids 
are  formed  ;  on  dry  distillation,  pyrocatechin  is  obtained. — Ibid. 
215-232. 
Preparation  of  tannin. — Oscar  Rothe  proposes  the  following 
process,  which  he  has  found  well  adapted  to  Chinese  galls :  8 
parts  powdered  galls  are  macerated  with  12  p.  ether  and  3  p- 
strong  alcohol  for  two  days,  the  liquid  decanted,  the  residue 
treated  with  the  same  solvents  and  expressed.  The  liquid  is 
decanted  from  the  sediment,  mixed  with  12  p.  water,  the  alcohol 
and  ether  recovered  by  distillation,  the  aqueous  solution  rapidly 
