358 
NICKEL  LINN^ITE. 
to  free  this  material  from  arsenic  and  sulphur,  it  is  first  finely 
pulverized  and  roasted  with  pidverized  coal.  The  residue  is  dis- 
solved in  muriatic  acid,  and  the  solution  diluted  with  much  water 
in  order  to  separate  the  bismuth.  If  the  liquid  is  now  mixed 
with  hypochlorite  of  lime,  the  iron  is  oxidised  to  a  peroxide, 
when  it  may  be  precipitated  with  the  arsenic  acid  existing  in  the 
liquid.  If  the  liquid  is  to  be  freed  from  copper,  a  current  of 
hydrogen  is  conveyed  through  the  same,  and,  having  separated 
the  prcipitate  produced,  the  cobalt  is  thrown  down  by  hypochlo- 
rite of  lime.  Now  the  nickel  may  be  separated  with  milk  of 
lime.  In  subjecting  the  precipitate,  with  carbon,  to  a  red  heat, 
the  metal  may  be  obtained  in  its  pure  state.  The  manufacture 
of  "Packfong"  in  Europe  is  not  of  a  very  old  date.  The  term 
is  synonymous  with  argentum,  German-silver,  British-plate.  Its 
composition  varies  considerably,  as  may  be  seen  from  the  follow- 
ing  table  : 
I. 
II. 
III. 
IV. 
Y. 
YI. 
.  88-00  . 
.    65-0  . 
.    43-8  . 
.    40-4  . 
.    55-0  . 
.  50-0 
Nickel  
.    8-75  . 
.    16-8  . 
.    15-6  . 
.    31-6  . 
.    20-0  . 
.  25-0 
.    13-0  . 
.    40-6  . 
.    25-4  . 
.    25-0  . 
.    25  0 
,    1-75  . 
.     3-4  . 
.     2-6  . 
98-50 
98-2 
100  0 
100-0 
100-0 
100-0 
It  may  be  seen  from  this  that  an  alloy  may  be  made  with  less 
than  10  per  cent,  of  nickel ;  but  the  wearing  quality  of  the 
metal  is  decidedly  injured  by  too  great  a  reduction  in  the  quality 
of  nickel. 
I  will  remark  that  No.  1  is  the  so-called  "white  copper," 
made  in  Suhl,  Germany,  a  century  ago,  with  copper  ores  con- 
taining nickel,  and  analyzed  by  Brandes.  No.  2  is  an  alloy, 
made  at  Paris,  which  is  capable  of  receiving  a  fine  polish  or 
gilding.  Nos.  3  and  4  are  Chinese  packfong.  No.  5  is  an  alloy 
as  used  for  knife  handles.  No.  6  is  adapted  for  forks.  The 
nickel  coins  of  Switzerland,  which  have  been  in  use  in  that 
country  since  1850,  consist  of  an  alloy  of  nickel,  copper,  zinc, 
and  silver.  The  proportion  of  nickel  and  zinc  in  the  20,  10,  and 
5  centimes  pieces  is  1*25.  While  the  amount  of  copper  in- 
creases with  the  decreasing  value  of  the  coin,  the  quantity  of 
silver,  on  the  other  hand,  decreases  with  the  smaller  value.  Th 
