22 GEOLOGICAL RECONNOISSANCE 



The quaternary beds of the northern part of Greene county afford, lo- 

 cally, a yellow ochre suitable both for a pigment and a dye-stuff. 



One of the localities, where I had an opportunity of viewing it in place, 

 is about one mile west of south of the " Pine," between the Gainsville and 

 Pocahontas road, near township 21 north, range 8, east of the 5th princi- 

 pal meridian. It is exposed here in a steep bank, near the bottom of a 

 hollow where a spring branch takes its rise on the north side of the ridge, 

 3 to 4 miles from Levi Boyd's farm. It lies a considerable distance under 

 the main upper gravel bed which shows itself in various places near the 

 top of this ridge and beneath underlying beds of pink, variegated, and fer- 

 ruginous sands. Its original color at the bank is a yellow, but by exposure 

 to heat, it acquires a red color, in which condition it has been used, by 

 some of the inhabitants of this part of the county, as a dye-stuff for woolen 

 goods. 



Its chemical composition is presented in the following analysis: 



Water (hygrometric) 2.99 C Silica 68.64 



Insoluble silicates 81.00<( Alumina tinged with oxide 



-. 



of iron 10.00 



Lime .44 



Magnesia .18 



Potash 1.20 



Soda ■ trace 



Peroxide of iron 10.00 



Protoxide of iron .78 



Oxide of manganese .20 



Alumina • 1.65 



Lime .45 



Magnesia .14 



Potash .31 80.46 



Carbonic acid .70 



Chlorine .02 



Phosphoric acid .14 



Sulphuric acid trace 



Water of hydration, loss, and 



ammonia 1 .70 



100.00 



This ochre contains seven and a half per cent of iron: it has a good 

 body and color; better than that of the French spruce yellow, and could be 

 used as a pigment for brick work, and outside work, even without washing, 

 as the texture is fine, and there is very little grit in it when carefully 

 selected. When burnt, it acquires a light red color; this change appears 

 to be due, more to the loss of its water of hydration, than to the peroxida- 

 tion of the fraction of a per cent of protoxide of iron, which it contains. 

 For the purposes of dying, it it used, by the country people, in its burnt 

 condition. 



At the " Pine," near by, diggings have been attempted in search of an 

 ore, supposed to contain silver; but with no success. The gravel and sand 



