1883. | Mineralogy. 871 
axis, and occur in narrow prisms, either as radiated aggregates or 
as fibrous masses, filling cavities in damourite or pyrophyllite. 
The crystals are ordinarily so disseminated and so small that 
they are perceived with difficulty. They frequently occur in 
fibrous masses like cyanite. In fact, they were at first thought to 
be cyanite. 
With cobalt solution a fine, blue color is obtained after heating. 
The mineral is insoluble in acid, except so far as a yellow discol- 
oration of the liquid is produced by the contained iron. Heated 
in the matrass, water is given off without decrepitation. The min- 
eral turns slightly yellow on exposure to the air. It has a fibrous 
appearance under the microscope. In its infusibility, its hardness, 
its cleavage, and, as Bertrand has shown, in its angles, the min- 
eral is similar to cyanite. 
ts composition, however, shows it to be a distinct species. 
The following is a mean of two analyses, after subtracting 16 per 
cent, of gangue: 
SiO, AlO, = _MgO,CaO,FeO H,O 
50.5 31.9 4 4.2 
giving the formula Al Oz., 2 SiO, + 3 H,0. 
Empholite appears to be a more hydrous variety of the new 
mineral davreuxite. 
Tue Cornwatt Tin orrs.—Mr. J. H. Collins contributes to the 
Mineralogical Magazine? his third paper on the tin ores of Corn- 
wall, England. The associated minerals are much the same as 
thinks.that it is a distinct species. It occurs massive, and also in 
spherical masses with radiated concentric structure, or in stellate 
groups, and sometimes in six-sided tables. Hardness, 1-2.5 ; 
Vol. v, p. 121. 
