Mr Connexx’s Description and Analysis of a Mineral. 47 
Its lustre is glistening and vitreous. Its hardness is interme- 
diate between that of fluor and that of felspar. It possesses a 
considerable degree of translucency. Its texture is imperfectly 
fibrous ; but in a few places the fibres appear diverging with con- 
siderable regularity, showing some approach to a crystalline struc- 
ture. Its specific gravity, at 67° Fahrenheit, was found to be 
2.3616: at 55°, it was 2.3622; we may take 2.362 as a mean. 
The most characteristic peculiarity of this mineral is its remark- 
able toughness and difficult frangibility. ‘To such an extent 
does this’ quality extend, that a mass of it cannot be broken in- 
to smaller fragments without great difficulty and repeated blows 
of a heavy hammer. 
The chemical characters of the mineral were as follows :— 
Exposed to heat in a glass-tube, it gave off water in considerable 
abundance, which did not affect the colour of litmus or turmeric, 
and did not stain Brazil-wood paper yellow, nor in the slightest 
degree corrode the tube. Neither was the glass in any degree 
attacked by the moisture expelled when the mineral was heated 
in an open tube with previously fused salt of phosphorus. Urged 
by the blowpipe in the platinum forceps, it did not swell up, but 
became opaque and white, and fused only on the edge, and with 
difficulty. Alone, on charcoal, the result was the same, except 
that the fusion on the edges was scarcely visible. With soda, it 
melted with effervescence into a semitransparent glass. With 
salt of phosphorus, it gave a colourless glass, showing silica as an 
opaque mass, in the midst of a clear globule, which, however. 
opalesced. on cooling, especially after the heat had been conti- 
nued some time. With borax, it fused into a transparent co- 
lourless glass. With soda, on platinum foil, no manganese re- 
action could usually be observed, although occasionally a feeble 
tint was visible. . With nitrate of cobalt, a fragment of the mi- 
neral gave no trace either of alumina or magnesia. | In order to 
ascertain whether it contained any phosphoric acid, a little of the 
mineral in powder was heated to drive off the water, and then 
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