AxovJe°mbef,hiam-}  Technical  Chemistry.  547 
utilizing  a  new  but  unpublished  process.  Storer's  method  proposed, 
but  not  yet  installed  on  a  commercial  basis,  applies  the  old  Hunt 
and  Douglass  copper  method  to  nickel  ores,  treating  nickel  oxide 
at  high  temperature  with  a  strong  solution  of  ferrous  chloride. 
In  the  treatment  of  lead,  tin,  silver,  mercury  and  zinc  ores, 
changes  during  the  year  seem  to  have  been  unimportant.  Several 
methods  have  been  proposed  for  treating  the  low-grade  argen- 
tiferous blende-galena  ores,  so  common  in  Colorado,  but  none  has  as 
yet  stood  the  test  of  successful  commercial  application. 
The  output  of  gold  has  been  further  increased  by  the  installation 
of  many  new  cyanide  works,  much  of  the  material  treated  in  these 
mills  being  the  tailings  from  old  amalgamation  plants  or  of  aban- 
doned dump  heaps.  Electrolyzing  the  cyanide  solutions  in  this  pro- 
cess is  becoming  more  common.  The  Sulman-Teed  method  of 
adding  a  small  quantity  of  cyanogen  bromide  to  the  lixiviating  solu- 
tion is  claimed  to  effect  increased  gold  extraction,  especially  in 
arsenic-bearing  ores,  but  it  is  also  asserted  by  many  that  the  loss  of 
cyanogen  by  this  method  is  too  great  for  success,  and  more  time 
must  be  allowed  for  further  evidence.  A  method  of  assisting  the 
free  access  of  the  oxygen  probably  necessary  to  the  solution  of  gold 
by  cyanide  solutions,  which  consists  in  violently  agitating  the  ore 
with  the  solution  by  means  of  air  introduced  into  the  mixture, 
under  considerable  pressure,  has  been  patented  and  is  now  being 
largely  advertised  under  the  name  of  the  "  Pneumatic  Process." 
A  possible  serious  objection  to  the  use  of  this  method  is  that  an 
increased  loss  of  cyanide  may  occur  from  excessive  oxidation  and 
decomposition  by  carbonic  dioxide.  During  the  years  immediately 
following  the  marked  success  of  the  cyanide  process  in  South 
Africa,  the  tendency  was  to  introduce  this  method  for  all  sorts  of 
ores  and  under  all  sorts  of  conditions,  whether  adapted  to  success  in 
this  way  or  not.  Now  the  proper  limitations  of  the  use  of  cyanide 
solutions  are  better  understood,  and  the  chlorination  process  is  again 
receiving  more  attention,  so  that  the  two  methods  are  now  begin- 
ning to  assume  their  proper  and  normal  relation  to  each  other.  In- 
creasing amounts  of  gold  and  silver  are  being  recovered  by  matting 
the  ores  with  copper-  and  sulphur-bearing  material,  Bessemerizing 
this  matte  to  blister  copper,  and  electrolyzing  the  product. 
In  several  industries  the  year  has  been  marked  by  the  beginning 
of  that  vast  shifting  of  location  from  coal  to  water-power  situations 
