TURQUOISE.
| To 1100 |
lbs.
| flint batch add |
| 90 |
" |
phosphate of lime, |
| 15 |
" |
arsenic, |
| 15 |
" |
calcined brass dust. |
VIOLET.
| To 100 |
lbs.
| flint batch add |
| 1 |
" |
calcined brass, |
| 1½ |
" |
zaffre. |
Receipts for window-glass are as numerous as
for flint. The following are in general use in England, so says
Gillender:--
CROWN GLASS.
| Sand, |
1400
| lbs. |
| Quick lime, |
480
| " |
| Sulphate of soda, |
560
| " |
| Charcoal, |
25
| " |
PLATE GLASS.
| Sand, |
300
| lbs. |
| Sulphate of soda, |
450
| " |
| Quick lime, |
100
| " |
| Nitre, |
25
| " |
| Charcoal, |
5
| " |
DIAMOND GLASS.
Four pounds of borax, one pound of fine sand;
reduce both to a subtile powder, and melt them together in a closed
crucible set in an air furnace, under a strong fire, till fusion is
perfect. Let it cool in the crucible, and a pure, hard glass, capable
of cutting common glass like a diamond, which it rivals in brilliancy,
is produced.
|
