246 W. Crookes—Radiant Matter. 
it from below upward. On darkening the room you see the 
diamond shines with as much light as a candle, phosphores- 
cing of a bright green. 
Next to the diamond the ruby is one of the most remark- 
able stones for phosphorescing. In this tube is a fine collec- 
phoresce with about the same col 
_, vow the ruby is nothing but crystallized alumina with 4 
little coloring matter. In a paper by Ed. Becq 
* Annales de Chimie et de Physique, 3rd series, vol. Ivii, p. 50, 1859. 
