216 
GLEANINGS  PEOM  THE  GERMAN  JOUENALS. 
and  finally  boiled  with  sugar  for  preserves  (Landerer,  in  Arch. 
d.  Ph.  cli.  299,  300.) 
Scammony. — -X.  Landerer  states  that  the  root  is  first  deprived 
of  its  juice  by  incisions,  and  afterwards  boiled  in  copper  vessels 
to  gain  an  aqueous  extract,  which  is  mixed  with  the  juice,  not  so 
much  as  an  adulteration,  but  to  render  its  strong  drastic  efi'ects 
milder.  He  likewise  reports  the  exportation  to  England  of  the 
root.— (Arch.  d.  Ph.  cli.  300,  301.) 
A  volumetric  estimation  of  nitrous  acid  has  been  experiment- 
ed with  by  Feldhaus.  He  uses  permanganate  of  potassa,  which  is 
added  to  an  acid  solution  of  the  nitrite,  the  nitrous  acid  of  which 
is  oxidized  to  nitric  acid,  while  protoxide  of  manganium  is 
formed  ;  the  reaction  is  completed  as  soon  as  the  acid  solution 
retains  the  color  of  the  permanganate.  The  most  suitable  tem- 
perature is  16  to  18^  C.  (61  to  65^  F.)  Spirit  of  nitrous  ether 
may  be  analyzed  in  the  same  way  if  it  is  previously  decomposed 
by  filcoholic  solution  of  potassa,  heated  to  212^^  F.,  and  largely 
diluted  with  water.  The  above  temperature  must  be  preserved, 
but  the  result  is  not  entirely  accurate,  because  the  brown  pro- 
ducts of  decomposition  produced  bj  potassa,  likewise  deoxidize 
permanganic  acid. — (Arch.  d.  Ph.  clii.  34 — 41.) 
Bitter  yeast. — Landerer  supposes  the  intense  bitterness  of  a 
yeast  of  beer  to  have  been  produced  by  nux  vomica,  but  inas- 
much as  no  experiment  confirmed  this  supposition,  there  appears 
to  be  not  the  slightest  foundation  for  it. — (Arch.  d.  Ph.  clii.  41, 
42.  ) 
Examination  of  extracts  hy  their  alkaloids. — Though  he  re- 
lates no  examples,  W.  Gundermann  recommends  the  following 
method  for  this  purpose  :  the  extract  is  rubbed  with  an  equal 
weight  of  water,  then  agitated  and  set  aside  with  four  times 
the  quantity  of  chloroform  ;  the  mixture  is  now  gently  heated  to 
separate  the  chloroform,  which  is  filtered,  and  the  residue  again 
treated  with  chloroform,  all  of  which  is  evaporated.  The  alka- 
loid is  dissolved  in  an  acid,  precipitated  by  ammonia,  redissolved 
in  alcohol,  and  evaporated  spontaneously.  Tinctures  are  previ- 
ously evaporated  to  a  syrupy  consistence. — (Arch.  d.  Ph.  clii. 
43,  44. 
