Concentration by Weathering. — KiinhalL i6l 
For lack of considerable development of ores of a high 
class, the mineral locations here briefly described are of no 
economic importance. The false estimation in which they 
had been held arose from failure to distinguish between the 
several kinds of material selected for analysis with due refer- 
ence to their relative quantitative development. As an exam- 
ple of one mode of genesis of iron ores, however, the occur- 
rences on the Cle Elum are not without significance. 
Specimens collected by myself to represent extreme types 
of the two kinds of material, the one altered (I) and the other 
imaltered(II), both from the Boss location, have been analyzed 
by Mr. Cabell Whitehead, Chemist of the Bureau of the Mint. 
The analyses are as follows: 
1 II 
ferric Oxide 82.56 50.26 
Ferrous oxide 1.24 o.6q 
Alumina 4.08 -3-7o 
Chromic oxiile 5.20 Not determined. 
Lime 0.28 1.27 
Magnesia i.oi 1.02 
Manganous oxide 0.30 0.43 
Oxide of Nickel 0.68 Not determined. 
Silica 3.10 14.40 
Water 1.53 Not determined. 
<)Q.()8 
Metallic iron 58.77 35. 16 
According to Mr. Whitehead's analysis the comparatively 
unaltered product (II) is remarkable for its high tenor of ferric 
oxide in relation to the low percentage of ferrous oxide. The 
figures point, of course, to epigenesis of the higher from the 
lower oxide in spite of the green streak and powder of this 
])roduct. 
The occurrences above noted clearly indicate, as it seems 
to me, the differentiation of iron oxides from an amorphous 
basic aggregate through weathering action on natural sur- 
faces by residual concentration incidental to isolation and 
waste of earthy residuums. Development of prismatic cleav- 
age and exfoliation of the same oxides on cleavage planes, 
even to the minutest sub-division, are incidental phenomena. 
That the oxidation of ferrous oxide in unisilicates to the higher 
oxide through meteoric influences in so dense an aggregate 
is thus limited, except in wet places, is not difficult to explain. 
^ lie fixation of ferric oxide is proliably not disconnected from 
