a light green, and.the present, after seventy-three years 7 
sure, is a purple @élo 
seen glass in origina 
the surface, sometimes producing all the effects of ground glass; 
and secondly, by an apparent formation of an infinitesimal coating 
of oxyd on the surface, on which the play of light gives all the 
colors of the rainbow, as with the action of light on the infinites 
imal grooves of the surface of mother-of-pearl. This is simply 
surface action, whereas the action of sunlight permeates ° 
whole body of the glass, wherever the rays directly strikept 
The writer of this article, (compiled in the midst of the busy 
duties of mercantile and official life,) makes no pretension xd 
accurate scientific knowledge, but gives the results of his obser 
vations and methodical experiments on a well known ie” 
es that they may add some mite to the ae 
dge, ors may stimulate and aid those who ar 
