426 
RESEARCHES  ON  BUCKWHEAT. 
aluminium  in  a  metallic  state  will  be  deposited  in  the  crucible. 
The  process  is  equally  applicable  to  the  production  of  mag- 
nesium. 
Sir  F.  C.  Knowles,  Bart.,  has  also  taken  out  a  valuable  patent 
for  the  manufacture  of  aluminium.    His  invention  consists  of  a 
method  of  preparing  the  cyanides  of  potassium  and  of  sodium, 
and  in  the  use  of  those  cyanides  in  the  making  of  the  aluminium. 
To  form  the  cyanides  the  patentee  combines  anhydrous  carbonate 
of  potash  or  anhydrous  carbonate  of  soda,  as  the  case  may  be, 
with  fine  charcoal,  in  such  a  proportion  as  to  convert  the  car- 
bonic acid  into  carbonic  oxide  by  the  action  of  heat,  and  to  de- 
compose the  alkali  used.    He  places  this  mixture  in  a  chamber 
with  lumps  of  charcoal,  such  chamber  being  of  fire-clay,  fire- 
brick, or  iron ;  and  then,  having  heated  the  same  sufficiently,  he 
passes  through  it  a  current  of  the  waste  gases  of  blast  furnaces 
used  in  smelting  iron  ores,  or  of  the  same  or  similar  gases  ob- 
tained intentionally  from  a  cupola  by  a  blast  of  air.  The  nitrogen 
contained  in  these  gases  combines  with  the  charcoal  to  form 
cyanogen,  and  this,  uniting  with  the  metallic  base  of  the  decom- 
posed alkali,  forms  a  vapor  of  the  cyanide  required,  which  can 
be  collected  by  sublimation  in  appropriate  chambers  and  cooled. 
To  make  the  metal  aluminium,  he  takes  one  or  other  of  the  above 
cyanides  and  the  chloride  of  aluminium,  and  by  passing  the  vapor 
of  the  chloride  of  aluminium  through,  or  otherwise  combining 
the  same  in  the  form  of  melted  chloride,  or  its  vapor,  with  the 
melted  cyanides  or  their  vapor,  he  obtains,  by  double  decomposi- 
tion, chloride  of  sodium  or  chloride  of  potassium  and  the  metal 
aluminium,  which  can  be  readily  collected  and  fused.  Pure 
alumina  may  be  added  to  the  materials  to  increase  the  yield  of 
metal  and  to  economize  the  cyanide,  and  this  he  recommends  to 
be  done  in  most  cases. — London Pharm.  Journ.,  Aprill,  1858. 
from  Mechanics'  Magazine, 
KE SEARCHES  ON  BUCK-WHEAT  CONSIDERED  AS  FOOD. 
By  M.  Isidore  Pierre. 
The  following  are  the  results  of  M.  Isidore  Pierre's  investiga- 
tions en  this  subject : — 
The  alimentary  preparations  made  with  buck- wheat  flour  form, 
