150 
OREIDE,  A  NEW  BRASS. 
A  NEW  DECOLORIZING  AGENT. 
M.  Ch.  Mene,  chemist  of  the  metallurgical  establishment  at 
Greuzot,  has  recently  made  various  experiments  which  seem  to 
prove  that  hydrated  alumina  may  be  substituted  for  animal  char- 
coal for  the  decoloration  of  liquids.  He  prepared  hydrated 
alumina  by  decomposing  alum  by  carbonate  of  soda.  Then  filter- 
ing and  washing  this  alumina  mixed  in  excess  with  different  color- 
ing matters  in  ebullition,  tincture  of  litmus  or  carmine,  syrups, 
and  molasses,  he  found  it  to  give  rise  to  colored  lakes,  which  fall 
to  the  bottom,  while  the  liquor  becomes  entirely  colorless.  For 
decolorizing  the  syrups  of  sugar,  they  use  in  the  establishments 
large  tubes  of  sheet  iron,  capable  of  containing  from  li  to  2 
tons  of  animal  charcoal ;  the  liquid  brought  into  contact  with 
this  charcoal  percolates  it  very  slowly  ;  if  the  charcoal  were  re- 
placed by  alumina  completely  insoluble  and  tasteless,  the  opera- 
tion of  decoloration  would  be  reduced  to  a  simple  cooking, 
followed  by  a  filtering  through  a  simple  cloth.  15  grammes  of 
alumina,  replaced  250  grammes  of  animal  charcoal  in  the  de- 
coloration of  a  quart  of  water,  colored  by  10  grammes  of  litmus  ; 
for  a  solution  of  sugar  colored  by  molasses,  7  grammes  of  alu- 
mina were  equivalent  to  125  of  animal  charcoal.  The  revivifica- 
tion of  the  alumina  will,  moreover,  be  much  easier  than  that  of 
the  charcoal. — Oomos.  in  Journ.  Franklin  Inst.,  Jan.,  1858. 
OREIDE,  A  NEW  BRASS. 
"MM.  Mourier  and  Valient,  of  Paris,  have  succeeded  in 
making  an  alloy  which  imitates  gold  sufficiently  near  to  merit 
the  name  Oreide.  The  properties  are  as  follows : — pure  copper 
100  parts  by  weight ;  zinc  17  ;  magnesia  6  ;  sal-ammoniac  3-6  ; 
quick  lime  1-80;  tartar  of  commerce  9.  The  copper  is  first 
melted,  then  the  magnesia,  salammoniac,  lime,  and  tartar  in  pow- 
der added  little  by  little  ;  the  crucible  is  briskly  stirred  for  about 
half  an  hour,  so  as  to  mix  thoroughly ;  and  then  the  zinc  is  added 
in  small  grains  by  throwing  it  on  the  surface,  and  stirring  until 
it  is  entirely  fused;  the  crucible  is  then  covered  and  fusion  main- 
tained for  about  85  minutes  ;  the  crucible  is  then  uncovered, 
