DALLAS COUNTY. 
87 
spread distribution on both sides of East Cypress and Cooks creeks 
and of West and East Tulip creeks has already been mentioned. In 
addition to the places at which good clays are already known, there 
is no doubt that they will also be found on the west side of Moro 
Creek and on the higher lands skirting the west side of Saline River 
in Dallas County. 
ANALYSES OF CLAYS. 
Analyses of clays in Dallas County are given in the following tabic: 
Analyses of Dallas County clays. 
Clays analyzed." 
Silica. 
Alum- 
ina. 
Ferric 
oxide. 
Titanic Tj 
oxide. lAme - 
Magne- 
sia. 
Soda. 
Pot- 
ash. 
Loss 
on ig- 
nition. 
Sand 
in air- 
dried 
clay. 
Cheatham clay 
72.82 
66.42 
71.27 
68.03 
62. 343 
66. 336 
50. 653 
60.700 
64. 734 
62. 166 
52. 269 
13.72 
21.19 
16.86 
17.19 
20. 631 
18. 966 
25. 450 
21. 567 
16.569 
26. 096 
32. 207 
1.267 
1.956 
2. 378 
3.589 
4.082 
2.008 
6.481 
5.000 
3.796 
.341 
1.781 
2.54 
1.02 
1.75 
1.49 
1.556 
1.869 
2. 591 
.447 
1.234 
1.302 
1.505 
0.63 
1.13 
.73 
.81 
.173 
.256 
.167 
.469 
.837 
.051 
.086 
0.75 
.82 
.77 
1.00 
.668 
.225 
.604 
1.583 
1.535 
Trace. 
.028 
1.08 
1.26 
.46 
.54 
.325 
.800 
.242 
.297 
1.395 
.252 
.341 
0.96 
""/u" 
1.00 
.729 
.379 
.742 
1.526 
1.685 
.364 
.271 
5.76 
7.76 
6.54 
6.31 
9.339 
8.130 
13. 100 
8.608 
7.334 
9.067 
11. 170 
50. 30 
37.28 
30.50 
Green's clay 
Tail's clay 
35.80 
16.73 
Crowder clay 
Clarks Creek clay. . . 
Ramsey clay 
Wormac's clay 
Little Cypress 
Creek kaolin 
Kilmer kaolin 
17.23 
3.46 
15. 25 
25. 14 
67.94 
38.57 
a The exact locations of the clays are stated in the preceding pages. 
Of the preceding eleven analyses the first four were made by W. C. 
Riley and the remaining seven by L. R. Lenox. It will be noticed that 
the clays analyzed by Doctor Riley show a much higher percentage 
of sand than those analyzed by Professor Lenox. The determination 
of the percentage of sand is at best only approximate and is a matter 
of individual judgment, and this accounts for the different percent- 
ages found. In two clays, which have to all appearances an equal 
amount of sand, the percentage of sand in the one as determined by 
Doctor Riley is about twice as great as the percentage in the other as 
determined by Professor Lenox. In comparing the sand contents of 
the clays this should be borne in mind. 
Each of the clays analyzed contains a considerable amount of 
titanic acid and smaller quantities of sulphuric and phosphoric acids. 
Neither of these substances is taken into consideration in the formula 
devised by Bischof for calculating the refractoriness of clays, so that 
in determining the refractoriness of the clays analyzed these constitu- 
ents have been disregarded. It is highly probable, however, that they 
exert some influence on the fusing point of clays. 
Several of the clays showing the largest percentages of titanic acid 
were washed and their coarser and heavier parts were examined under 
a microscope. Owing to the fragmentary condition of the particles 
it was not possible to identify any of them except the quartz. 
