176 FEATHER-ALUM — GILPIN. 
Locality. Sulphuric Alumina. Ferrous. Water. 
Acid. Oxide. 
Moorfield... .36.03 10.91 9.37 42.03 
Hurlet..... .35.60 7.12 13.56 43.71 
Sl iit. SOIR 5.20 20,70 43.20 
Bur ont.s. ss Dore 2.85 19.35 438.58 
Freyenwalde 43.90 15.25 7.50 33.10 
Glace Bay.. .39.71 9.13 16.57 35.09 
It would be interesting to know how much time was occu- 
pied in the formation of this mineral at the Glace Bay Mines, 
some of the fibres being one-third of an inch in length. It can, 
however, only be remarked that the gallery in which it occurred 
had been excavated about twelve years ago. 
Another hydrous sulphate, found as a product of decomposition 
in Coal Mines, is known as Alunogen. 
The following analysis of a specimen occurring asan efflor- 
escence at the Scotia Mine in Cumberland County, is taken from 
the report of the Canadian Geological Survey for the year 
1878-79. 

Sulphumie: Acids... . 36°935 
Aumann, oct: ede e ase sic ae 13.479 
Ferrie Oxide i: pice as ge 2.888 
Ferrous Oxide, 8.0.0.4 os <e 157 
aU RI ct beta lotecttisee te oe 45.109 
MM. Satins otoacoustic tates 140 
IMAOMESTRS sie ici jae ani vies sl 138 
Potashis c Siemon reser: aie 087 
PSION ew yer eave ovene siege 131 
iasolwbles 2). 25 oa « sae h Zao 
99.299 
Some years ago a hydrous sulphate of Alumina and Magnesia 
of similar origin was found on Silurian Slates at Newport, and 
was shown by the late Professor How to be identical with 
Pickeringite, a mineral up to that time known only in Peru. 
