No.  III.  One  hundred  parts  of  sand,
50  of  potash,  6  of  air-slaked  lime,  and

1  of  cobaltic  oxide.
Sapphire  Blue  is  obtained  by  adding
from  I  to  3  per  cent,  of  cobaltic  oxide.
Azure  Blue  is  produced  with  an  ad-
dition of  1  per  cent,  of  cupric  oxide.
Golden  Topaz  Glass  is  produced  by
adding  ^  per  cent,  of  uranic  oxide  to  a
crystal-glass  composition.
Green  Glass ^  No.  I.  Fifty  parts  of
sand,  15  of  soda,  5  of  chalk,  1  of  salt-
petre, 5  to  10  of  ferric  oxide,  and  3  to
10  of  cupric  oxide.
No.  II.  Thirty-seven  and  a  half  parts
of  sand,  12.5  parts  of  soda^  6  of  chalk,  2
of  saltpetre,  2  to  5  of  feme  oxide,  and

2  to  5  of  cupric  oxide.
GLASS— COMPOSITION  OF,  ETC.
145


No.  III.  Sixty  parts  of  sand,  20  of
soda,  6  of  chalk,  1  of  saltpetre,  0.d  to  1
part  of  chrome  ^reen.
No.  IV.  One  hundred  parts  of  sand.
50  of  potash,  8  of  air-slaked  lime,  and
2  of  chrome  green.
No.  V.  One  hundred  parts  of  sand,
85  of  miniuiu,  38  of  potash,  4  of  oxide
of  antimony,  and  2  of  cobaltic  oxide.
Hyalite  Glass,  No.  I.  One  hundred
parts  of  sand,  66  of  potash,  8  of  air-slaked
lime,  6  of  arsenious  acid,  5  of  cobaltic
oxide,  5  of  pyrolusite,  and  5  of  ferric
oxide.
No.  II.  One  hundred  parts  of  sand,
82  of  minium,  38  of  potash,  8  of  salt-
petre, 4  of  cobaltic  oxide.  4  of  pyrolu-
site, 6  of  iron  scales,  and  6  of  copper
scales.
Orange  Glass  is  obtained  by  adding
2  per  cent,  of  ferric  oxide  and  §  per
i?ent.  of  pyrolusite  to  the  composition
v^r  yellow  glass,  which  see.
