22 A. R. Leeds—Contributions to Mineraiogy. 
The amount of nickel in this iron is exceptionally large. In 
comparing all the analyses conveniently accessible, I find only 
one other meteoric iron showing so much nickel. That o 
Greenville, Tenn., by Clark, has Ni 17-10 Co 2°04=19°14, which 
is the highest before recorded, so far as I can discover. That 
of Tazewell County, Tenn., by Smith (this Jour., H, xix, 155), 
has Ni 14°62 — 15°02 and Co 0-48 to 0°50 ; that of Cape of Good 
Hope, by Uricochoea (Rammelsberg, Mineralchemie, pp. 919-920), 
contains Ni 15:09 and Co 2°56 = 17°65, almost identical with 
the sum of Ni and Co in the Shingle Springs=17°777 per cent. 
The Clairborne, Ala., iron, analyzed by Jackson (this Jour., 
I, xxxix, 335, and quoted by Gmelin, v, 395 of Cavendish ed.), 
gave him Ni 24°708—27°708, but this was subsequently reduced 
by A. A. Hayes (this Jour., I, xlviii, 153) to Ni 12°665 per cent. 
Very few of the analyses have obtained over 10 per cent of Ni, 
and an average of this element in some 80 analyses compared 
by me, is not over seven and a quarter per cent. 
Art. V.—Contributions to Mineralogy ; by ALBERT R. LEEDS, 
Prof. of Chemistry in the Stevens Institute of Technology. 
I. A Hydrous Unisilicate approaching Pyrosclerite. 
Occurs at the so-called Magnesia Quarries, from which the 
deweylite, at one time largely employed in the manufacture of 
Epsom salts, was quarried, in the Bare Hills, Md. Since this 
mineral, in common with the other hydrous unisilicates of a 
similar character, is to be regarded as most probably one of the 
results of a process of alteration which has operated powerfully 
upon the rock masses constituting the Bare Hills, it is important 
to mention exactly its method of oceurrence, which I do from 
a personal examination of the locality. It is found in a nearly 
vertical seam several inches wide, between walls of deweylite 
on one side and tale on the other: the deweylite graduates into 
albite; the tale is bounded by common serpentine with folia, 
whose surfaces are normal to the line of contact with the tale. 
H.=15-—2. G.=2°558. Color grayish, inclining in some 
places to bronze-yellow. Golden luster on fresh cleavage sur- 
face. Translucent in thin folia; transmitted light, brownish- 
sided Brittle. Orthorhombic. Largest crystals from this 
ocality 3™™- long in the direction of the macrodiagonal. Basal 
cleavage eminent. Optically biaxial. Heated in closed tube 
ields much water of a neutral reaction, and exfoliates vigorously. 
he folia are pearly-white and opaque. Decomposed by hydro- 
* A brief notice of this meteoric iron was published by Prof. O. U. Shepard, in 
this Journal for June, 1872. 
