38 
TRANSACTIONS OF THE TEXAS ACADEMY OF SCIENCE. 
tine; Nos. 13 and 14, mulatto soil and subsoil from Cherokee county; 
and 15 the red soil resulting from the decomposition of glauconitic beds 
in Lee county. All of them are rich in potash and phosphoric acid. 
ll* 
12* 
13+ 
14+ 
15* 
Insoluble matter. 
92.943 
79.954 
72.09 
59.14 
74.983 
Soluble silica. 
1.009 
1.251 
.23 
.25 
3.8S5 
Potash.. 
.111 
.067 
.10 
.23 
.718 
Soda. 
.093 
.060 
.39 
.46 
.131 
Lime. 
.147 
.168 
.28 
.16 
.258 
Magnesia. 
.077 
.012 
.22 
.30 
.530 
Manganese. 
.051 
.170 
.032 
Iron. 
1 .614 
8.478 
16.99 
25.73 
9.333 
Alumina. 
1.470 
6.078 
2.78 
3.14 
5.301 
Phosphoric acid. 
.193 
.194 
.23 
.44 
.102 
Sulphuric acid. 
.020 
.006 
1.54 
.31 
.028 
Water and organic’. 
2.201 
4.109 
6.10 
10.39 
4.717 
99.929 
100.547 
100.95 
100.55 
100.018 
* Cotton Production, Tenth Census, p. 25. 
t First Annual Report Geol. Sur. Tex., p. 37. 
Lignitic Beet.— Three principal varieties of soil mark this the great¬ 
est of all the Tertiary belts. 
1st. A coarse white to light gray sandy soil, which stretches from Cass 
county on the east to Carrizo Springs in Dimmit county on the west, 
and which through the greater part of its extent supports a fine growth 
of oak and hickory. While as soils these sands are not of much value, 
their importance is nevertheless very great, as they form the catchment 
area for water which may be had south of them for many miles, by wells, 
either shallow or artesian. 
2nd. Light gray, brown and chocolate sands and sandy loams, with 
stiffer loams in the prairies. These are derived from the sands and clays 
accompanying the lignite deposits. 
3rd. Black shelly to sticky soil, derived from the limy clays at the 
base of the Tertiary and usually forming a prairie country. 
The lignitic soils are usually rich in phosphoric acid and often contain 
large percentages of potash, but this element is at times deficient. The 
anatyses given are No. 16, sandy upland soil from Wood county; Nos. 
17 and 18, light sandy soil and subsoil from Smith county; and 19 and 
20 gray sandy upland soil and subsoil from Robertson county. 
