GLEANINGS  FROM  GERMAN  JOURNALS. 
217 
GLEANINGS  FROM  GERMAN  JOURNALS. 
By  John  M.  Maisch. 
A  new  delicate  test  for  alkalies.— 'Bcettger  recommends  for 
this  purpose  an  alcoholic  solution  of  alkanin,  with  which  Swedish 
filtering  paper  is  impregnated ;  after  drying,  the  paper  is  to  be 
kept  in  well  corked  bottles.  The  minutest  trace  of  ammonia 
turns  the  red  color  blue.  If  this  red  paper  has  been  rendered 
blue  by  a  very  dilute  solution  of  carbonate  of  soda,  the  red  color 
will  be  restored  by  minute  traces  of  free  acids. — Neues  Jahrh.f. 
Fharm.,  1869,  Mai  und  Juni,  311. 
I^ure  iodate  of  potassa,  according  to  Stas,  is  readily  obtained 
by  heating  a  mixture  of  equal  equivalents  of  chlorate  of  potassa 
and  iodide  of  potassium  in  a  retort  placed  in  a  sand  bath,  just  to 
the  temperature  of  the  fusing  chlorate.  If  the  temperature  is 
not  carried  too  high,  all  the  oxygen  of  the  chlorate  is  transferred 
to  the  iodide.  The  chloride  formed  is  extracted  by  cold  water, 
and  the  residue  is  repeatedly  crystallized  from  hot  water.  The 
iodate  thus  prepared  never  turns  yellow  on  exposure,  which  is 
always  the  case  when  iodine  is  oxidized  by  chlorate  of  potassa. 
— Ibid.y  312,  from  Journ.  f.  Pract.  Ghem.  1869,  251. 
To  detect  copper- arsenic  colors^  Puscher  recommends  the  use 
of  ammonia,  which  dissolves  them  with  a  blue  color,  and  on 
evaporation  leaves  a  dirty  yellowish-green  residue.  If  the  blue 
solution  leaves,  on  evaporation,  a  light  blue  residue,  the  material 
was  dyed  or  colored  with  a  blue  or  green  copper  compound,  free 
from  arsenic. — Ihid.^  314,  from  Bayer.  Gewerheztg^  1869,  35. 
Adulteration  of  sulphuric  acid. — J.  Fleischer  has  met  with  oil 
of  vitriol,  manufactured  in  Stettin,  in  which  sulphate  of  soda  or 
of  magnesia  had  been  dissolved  to  increase  its  specific  gravity. — 
Ihid.,  315,  from  D.  Indust.  Zeit.  1869,  208. 
Preparation  of  Oxygen  at  ordinary  temperature.  By  Prof. 
Boettger. — A  mixture  of  the  hyperoxides  of  lead  and  barium 
may  be  kept  for  any  length  of  time  without  being  decomposed. 
If  weak  nitric  acid  (of  about  9°  B.)  be  added  to  it,  pure  oxygen 
is  evolved  perfectly  free  from  ozone  and  antozone ;  the  peroxide 
of  hydrogen  which  is  first  generated,  in  its  nascent  state,  is  de- 
composed by  the  binoxide  of  lead,  water  and  ordinary  inactive 
