386 Dr Brewster on the Phos]phorescence of Minerals, 
Names of the Minerals, 
Colour of the 
Minerals. 
Colour and Intensity of their 
Light. 
Sulphate of strontites 
Bluish 
A fragment shone pretty bright 
lead 
Transparent 
Faint and by fits 
25 Anhydrite 
Reddish 
Faint light 
Sodalite 
Dark green 
Pretty bright 
Bitter spar 
Yellowish 
Faint white 
Red silver ore 
Red 
Pretty bright, but flitting 
Barystrontianite 
White 
Faint 
30 Arseniate of lead 
Yellowish 
Bright white 
Sphene 
Yellow 
Bright white 
Tremolite 
Whitish 
Reddish-yellow 
Mica 
Greenish 
Whitish 
from Wayeatz 
Black 
White specks 
35 
Brown 
Pretty bright 
Titanium sand 
Black 
Feeble specks 
Hornstone 
Grey 
Yellowish 
Table spar, Dognatska 
Whitish 
Yellowish 
Lapis lazuli 
Blue 
Faint 
40 Spodumene 
Greenish 
Faint 
Titanite 
Reddish 
Extremely faint 
Kyanite 
Yellowish white 
Bluish 
Calamine 
Brown 
Faint 
Augite 
Green 
Pretty bright 
45 Pelalite 
Reddish tinge 
Blue and very bright 
Asbestos rigid 
— 
Pretty bright 
Datholite 
Transparent 
Bright 
Corundum 
Browm 
Bright 
Anatase * 
Dark 
Reddish-yellow 
50 Tungstate of lime 
Yellowish- white 
Brilliant like a burning coal 
Quartz 
Very faint 
Amethyst 
The phos- 
Faint 
Obsidian 
phorescence 
Pretty bright , dirty blue 
Mesotype from Auvergne 
of these nine 
Very faint 
55 Glassy actynolite 
V minerals 
Little specks 
Ruby silver 
was obser- 
Rather bright 
Muriate of silver 
ved in the 
Blue 
Carbonate of copper 
pistol barrel. 
Very faint 
Green Telesie 
- 
Pale blue, and pretty bright 
As Mr Wedgwood has maintained that minerals can never be 
entirely deprived of this property by any number of heatings 
or by any degree of heat,” I resolved to try the experiment 
with a specimen of green fluor-spar, which was highly phos- 
phorescent. In order to prevent it from flying to pieces, as it 
always does when exposed to heat, I wrapped it tightly in pla- 
tinum foil, and exposed it for about an hour to the heat of a 
common fire. When taken from the crucible, it had entirely 
lost its green colour, but was in no way cracked or injured by 
* The phosphorescence of anatase is entirely different from that of other mine- 
rals. It appears suddenly like a flame, and is soon over. 
