Glass Manufacturing:
See also Ceramics.
The blue tint of the common poison bottle is got by the addition of black oxide of cobalt to the molten glass; the green tint of the actinic glass bottle is obtained in the same way by the addition of potassium bichromate, which is reduced to the basylous condition, and the amber tint is produced by the addition of impure manganese dioxide, a superior tint being produced by suphur in one form or another. The formulas for various kinds of bottle glass, which indicate the general composition of almost all glasses, are:
White Glass for Ordinary Molded Bottles.—
| Sand | 64 parts by weight |
| Lime | 6 parts by weight |
| Carbonate of sodium | 23 parts by weight |
| Nitrate of sodium | 5 parts by weight |
White Flint Glass Containing Lead.—
| Sand | 63 parts by weight |
| Lime | 5 parts by weight |
| Carbonate of sodium | 21 parts by weight |
| Nitrate of sodium | 3 parts by weight |
| Red lead | 8 parts by weight |
Ordinary Green Glass for Dispensing Bottles.—
| Sand | 63 parts by weight |
| Carbonate of sodium | 26 parts by weight |
| Lime | 11 parts by weight |
A mixture for producing a good green flint glass is much the same as that for the ordinary white flint glass, except that the lime, instead of being the purest, is ordinary slaked lime, and the sodium nitrate is omitted. Sand, lime, and sodium carbonate are the ordinary bases of glass, while the sodium nitrate is the decolorizing agent.