T. Gaffield on the action of Sunlight on Glass. 245 
the interesting fact, that, even after a single day’s exposure toa 
uly sun, the change of color will, in some instances of the 
ence. 
“So remarkable was the change in a week, affecting nearly all 
the light-colored glasses, that he commenced a third experiment 
e * - . 
Specimen, which, after repolishing, still exhibited the same 
ello 
y iow color. alled colorless win- 
and hue from the 
