The Function of Arsenic in Potash-Lead Oxide-Silica Glasses

JSGT 1927 V11 T065-T076 

In a previous paper on the function of arsenic in making soda–lime–silica glasses we have seriously called into question some of the views current about its action. In the case of the soda–lime–silica glasses, we have definitely shown that between 75and 100% of the arsenic added is usually retained in the glass in commercial melting's, and we shall show in later papers that even high temperature melting and the presence of reducing agents do not very seriously diminish the amount of arsenic unless the reducing agent is present in very considerable excess. The rate of melting of soda–lime–silica batches not containing nitre was not found to be assisted by the addition of arsenic, and in so far as the refining process is regarded as being dependent on the mechanical action of the arsenious oxide escaping as vapour, the view that it assists refining is untenable, because the arsenic remains in the glass.

S. English, Edith M. Firth & W. E. S. Turner