120 
ON  ALUMINIUM. 
ALUMINIUM — THE  PROGRESS  IN  ITS  MANUFACTURE. 
By  W  J.  Taylor. 
|From  the  Proceedings  of  the  Academy  of  Natural  Sciences  of  Philada.,  January,  1857.] 
The  use  of  sodium  in  the  reduction  of  metals  from  their 
chlorides,  as  has  been  so  successfully  accomplished  within  the 
last  two  years,  may  be  justly  considered  a  great  progressive  step 
in  science. 
Aluminium  has  been  the  first  in  which  this  process  has  been 
perfected.  What  the  other  metals  are  which  will  be  reduced 
successfully  from  their  chlorides  by  the  use  of  sodium,  the  future 
will  determine.  Some  facts  concerning  the  early  history  of 
aluminium,  the  progress  made  in  its  manufacture,  and  the  nu- 
merous uses  to  which  it  can  be  applied,  will  not  be  uninteresting. 
Much  confusion  existed  in  the  minds  of  the  early  ajchymists 
regarding  the  oxide  alumina.  They  knew  of  an  alum  which  was 
brought  from  the  East,  which  they  regarded  for  a  long  time  as 
sulphuric  acid  combined  with  an  earth.  Stahl  and  others  also 
mistook  this  earth  for  lime.  Geoffroy,  in  1728,  pointed  out  its 
existence  in  clay  ;  Marggraff,  in  1754,  proved  it  to  be  a  substance 
having  a  separate  existence  and  peculiar  characters.  To  Oerstedt 
belongs  the  credit  of  first  preparing  the  chloride  of  aluminium, 
from  which  compound  Wohler,  in  1827,  succeeded  in  first  elimi- 
nating the  metal.  Wohler  first  obtained  aluminium  in  the  form 
of  a  grey  powder,  by  heating  gradually  in  a  porcelain  crucible 
over  a  spirit  lamp  equal  volumes  of  metallic  potassium  and  chlo- 
ride of  aluminium;  other  chemists,  by  slight  modifications  of  this 
process,  have  obtained  aluminium  in  the  form  of  the  grey  pow- 
der, as  first  obtained  by  Wohler.  # 
To  M.  Sainte  Claire  Deville  belongs  the  credit  for  first  improv- 
ing the  process,  so  as  to  produce  aluminium  in  such  quantities 
that  its  characters  as  a  metal  could  be  fully  investigated.  M. 
Ste.  Claire  Deville  used  in  his' process  sodium  as  a  substitute  for 
potassium.  (It  requires  39  parts  of  potassium  to  produce  the  same 
reductive  effect  as  23  parts  of  sodium.)  At  the  time  of  his  first 
experiments  sodium  was  worth  one  hundred  dollars  per  pound ; 
he  so  improved  the  process  for  making  this  metal  as  to  reduce 
the  price  to  ninety  cents  per  pound. 
At  this  time  the  chloride  of  aluminium  was  regarded  with 
