Zinc sulphide. Phosphorescent 1 gramme
Zinc sulphide. Phosphorescent 1 gramme, in sealed glass tube.
Three specimens, two of which are radioactive materials, comprising: (1) Zinc sulphide, phosphorescent. (2) Radium barium bromide, anhydrous. (3) Radium barium bromide, anhydrous.
Zinc sulphide. Phosphorescent 1 gramme, in sealed glass tube.