OF ARKANSAS. a1 
texture is fine, and forms a plastic mass with water. Its composition is 
shown by the following chemical analysis: 
Moisture «+. -.eee eee eee 01.10 (Silica-.-+.+-.0+ eevee ees 69.7 
Insoluble siliceous earth... 89.75 < Alumina tinged with oxide of 
Oxide of iron. ...eeeee ees 3.86 ae) | i i a 19.0 
TW se a sear) oben leee 8 Ree 88 Sina: gece ee are oe eer eree ert 2 
Magnesia Oe ee ee ee eee 33 Magnesia - sss rreseeneeenee wl 
Potash s<8a4066ioskeewe. oes 15 Potash. sock ese.saaee wage: Sy 
Carbonic acids .++++1eeees 1.00 | Soda +--+. eee. Fees ee rece .05 
Chlorine. 60.2 eaaecw eee se .60 =F 
Phosphoric acid. +. ++.+++e+ 075 | 89.75 
Water of hydration (not dri- 
ven off at 300 deg. F.,) 
trace of ammonia and loss 8.255 
100.000 
This clay contains 4.79 per cent. less alumina than the Hickman county 
clay belonging to the same geological era; about 0-701 per cent. less lime, 
and 0-34 less alkalies. It will, therefore, make a whiter ware, be less 
fusible, and less liable to crack. 
Ihave manufactured small crucibles out of this clay, and find that it 
produces an excellent and strong article. The moulded clay is not liable 
to crack in drying, without addition of silica or siliceous earth, nor during 
the burning; and the crucibles manufactured therefrom resist sudden 
changes of temperature without cracking. The burnt biscuit ware is even 
rather lighter colored than the original clay, which is of avery light cream 
color. It resists fusion at a high temperature. 
Besides being valuable for the above purposes, this clay would, proba- 
bly, be found of excellent quality for modelling, and various other uses; it 
is, therefore, well worthy the attention of the potter and the artist. 
The section at Chalk Bluffs, does not extend low enough to enable the 
observer to see what underlies this clay; but from the position of beds of 
clay of, apparently, the same age, found in other western and southern 
states, it is probably interstratificd amongst the orange and ferruginous 
sands, that are subordinate to the shell marls, which constitute the upper 
member of the quarternary; occupying, therefore, the same geological 
horizon, as the white clays at the base of the section described in the first 
volume of the geological report of Kentucky, on pages 20, 21 and 22 of 
that volume, and the corresponding clays which, I understand from Dr. E. 
W. Hilgard, geologist of Mississippi, are interstratified in the “orange 
sand,” of the state of Mississippi; on this account it is probable that ferru- 
ginous, orange-colored sands occur in this part of Arkansas still beneath 
this clay; but concealed from view under the drainage of the country. 
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