Phosphorescence in a Photoelectric Cell of Fused Quartz

While using a quartz spectrograph and a fused quartz photoelectric cell, a large leak was observed immediately after shutting off the exciting light. This was apparently due to a phosphorescence of the fused quartz. Only a few seconds exposure sufficed to give the saturation value. The current decreased according to the regular law of decay of phosphorescence reaching zero in about one minute