58 GEOLOGICAL REPORT. 1T97, 98 



97. Materials for Glass. — The deposit of white pulverulent 

 silica, which has been mentioned (130,81 2 ), is of very superior 

 quality for this purpose, and being in a fine state of division, it 

 would be preferable to the sand commonly used, for rapidity of 

 fusion. The largest beads which could be fused before the blow- 

 pipe, of a mixture of this material with soda, were perfectly color- 

 less in either flame. There are portions of it which are tinged with 

 iron, but by far the larger part is of great purity, and might be 

 mined with ease, like coal, by means of horizontal galleries. 



The outcrop examined by me is in a small valley opening on that 

 of Big Bear Creek, about 1 mile S. of Eastport (TO 2 ). The 

 same stratum has been struck in wells at the latter place, and the 

 deposit is probably co-extensive, in Mississippi, with the hornstone 

 breccia itself, which overlies it, and occupies all of T. 2, R. 11 E., 

 the N. part of T. 3, and N. E. \ of T. 2, R. 10 E.— The inhabi- 

 tants designate both the white pipeclay and the silica as "chalk ;" 

 the latter may, however, be readily distinguished from the former 

 by its not affording any permanent white streak on wood ; it "does 

 not write.'' It is important to observe this difference, for the white 

 pipeclay would be utterly useless in glass-making. 



Occurring, as this material does, close to the banks of the Ten- 

 nessee river, easily mined, and preferable as it undoubtedly would 

 be to the coarse sand so often employed in glass-making, and which 

 itself is shipped to considerable distances, it would seem that the 

 exportation to the Pittsburg glass works, at least, via Tennessee 

 and Ohio rivers, could be made a profitable business. For the 

 manufacture of the soluble glass, or silicate of soda, now coming 

 into use so extensively, a more desirable material could scarcely be 

 procured. 



98. Waters of the Carboniferous Formation. — Most of those 

 occurring on its territory are derived from the overlying pebble for- 

 mation, and are remarkably pure — as also, of course, are those 

 flowing from the siliceous sandstone. The chalybeate occurring 

 at Peden's (H62), is probably derived from the laminated clays of 

 the Eutaw group. 



The Red Sulphur Spring in Tennessee (T. 1, R. 10 E.) is the 

 only prominent example I know, of a mineral water which is cer- 

 tainly derived from the rocks of this formation. It would seem 

 that any spring or well reaching the black shale underlying the 



