FEATHER-ALUM — GILPIN. 175 
Art. IT].—FErATHER-ALUM (HALOTRICHITE) FROM GLACE Bay, 
Care Breton. By E. Gitein, F.G. S., F. RS. C, 
CuriEF INSPECTOR OF MINES. 
(Read March 9th, 1885.) 
DvRING a yisit to the Glace Bay Coal Mines, in Cape Breton 
County, I had specimens of Melanterite, or Green Vitriol, and a 
few pieces of a white fibrous mineral brought to me from some 
heaps of shale and slack coal, which were being removed from 
the pit. The former mineral is not unfrequently met with, the 
latter being new to me I made two analyses of it, and thought 
that the results might interest some of the members of the 
Institute. 
The mineral is of a white colour, turning brown on exposure, 
and of a delicate fibrous structure. It is soluble in water and 
The analyses gave : 
Vrotoxide‘of Irom.) .<.51- 16.570 

PATNI TINA Peg actene S<i% dene Cotes Ou Mel 
SlphuaricvAcid .5), irises syste 39.715 
AS ore ey estar ee a a oe 35.097 
SHCA ee Sepsis ats Genk. teetels Traces 
Ma omesinen duit. «.csteraaticrs ee odo 
Terraeer a eee eat) ooo ete pa oid LO. 
100.513 
This analysis, while not agreeing exactly with any given in 
Dana’s mineralogy, would apparently place the mineral in the 
Halotrichite group. 
The following table shews the composition of a number of 
specimens of Halotrichite compared with that of the mineral 
under consideration, 
