A Note on the Influence of some Batch Constituents on the Colour of Glass

JSGT 1935 V19 T040-T042

It sometimes happens that when one branches from the broad road of routine into a fork, the way is not always so smooth as the entrance might indicate. An example of this was experienced in the conversion of an ordinary soda–lime–silica glass into a glass in which some lime was replaced by barium oxide (to the extent of about 2–2½%) in order to give a softer glass without increasing the soda content. Since barium produces colourless salts, the way seemed clear and free from complications. It soon became evident, however, that all was not well with the colour of the glass. The glass steadily became more and more green despite efforts to adjust the selenium short of panic measures.

E. J. C. Bowmaker