1. T. Furukawa, S. A. Brawer andW. B. White, to be published.
2. M. F. Mydlar et al, Phys. Chem. Glasses 11 (1970) 196.
3. M. Leventhal andP. J. Bray,ibid 6 (1965) 113.
4. G. C. Milnes andJ. O. Isard,ibid 3 (1962) 157.
5. B. M. Cohen et al, J. Non-Cryst. Solids 12 (1973) 177.