22 M. Rose’s Analyses of several Species of Mica. 
acid, by exposing it to the fire. That which contains about a 
per cent, of it, loses its lustre and becomes matted, while that 
which contains only traces of it assumes a metallic lustre. The 
following are the results of M. Rose’s analyses of three kinds of 
mica. 
1. Mica of Broddho near Fahlun. 
Silex, 46.10 
Oxide of Iron, 8.65 
Alumine, 31.16 
Oxide of Manganese, 1.40 
Potash, 8.39 
Fluoric Acid^ 1.12 
Water, 0.87 
98.13 
2. Mica from Kimito in Finland. 
• Silex, 46.358 
Oxide of Iron, 4.533 
Alumine, 36.800 
Oxide of Manganese, 0.02 
Potash, 9.22 
Fluoric Acidy 0.76 
Water, 1.04 
98.713 
3. Mica from the Iron Mine qfUto. 
Silex, 47.5 
Oxide of Iron, 3.2 
Alumine, 37.2 
Oxide of Manganese, 0.9 
Potash,. 9.6 
Fluoric Acid, 0.56 
Water, *..1.39 
100.35 
Stockholm, ) 
Sept 21. 1820. j 
