They are used to replace some of the silica, than which they are more fusible.
Care must be taken in these preliminary operations to avoid heating the more fusible glasses sufficiently to soften them.
Hard glass, which contains much calcium, is more apt to devitrify than the more fusible varieties.
Antimony renders iron cold short, the alloy is harder and more fusible, and approaches in character to cast iron.
Silica, also, when mixed with the other earths, renders them more fusible than is its own mixture with oxide of iron.
We are therefore compelled to make use of the property possessed by the earths, of rendering each other more fusible.
If the cementation be continued too long, the steel acquires a darkish fracture, it is more fusible, and incapable of welding.
The process of sweating out by heat the more fusible metals of an alloy.
The union of metallic surfaces by means of a more fusible metal fluxed between them.
The Chinese glaze is also the more fusible, on account of the addition of lime to the petuntse, which the French use pure.