98 



GULF TERTIARY OF TEXAS. 



than that in which it naturally occurs. This does away with the inconven- 

 ience of having it crumble. Such bricks are considerably used in France and 

 Belgium* for railroad and other purposes. 



3. Lignite of a black color, in a finely powdered state, has been used in 

 England, under the name of "Cologne Earth," as the basis of a black paint. 



4. Lignite has been successfully used in place of bone-black in clarifying 

 sugar. 



ANALYSES OF TEXAS LIGNITES AND COAL. 



Lignite — Rockdale, Milam County 



Atascosa County 



Athens, Henderson County. . . . 



Rusk County. 



Calvert Bluff, Robertson County 



Shelby County 



Leon County 



Rockdale, Milam County 



Water. 



Volatile 

 Matter. 



Fixed 

 Carbon. 



Ash. 



19.925 



52.425 



22.000 



5.650 



13.285 



59.865 



18.525 



8.325 



9.100 



42.200 



1.315 



41.325 



16.825 



46.325 



31.475 



5.375 



16.475 



58.400 



18.675 



6.450 



18.260 



43.510 



29.530 



8.700 



14.670 



37.320 



41.070 



6.690 



13.800 



43.550 



36.830 



5.320 



Sul- 

 phur. 



1.235 

 2.360 

 0.625 

 1.090 

 1.330 

 2.460 

 0.250 

 1.350 



ANALYSES OF LAREDO AND EAGLE PASS COAL. 





Water. 



Volatile 

 Matter. 



Fixed 

 Carbon. 



Ash. 



Sul- 

 phur. 



Laredo Coal 



2.5 

 3.675 



51.05 

 39.42 



39.1 

 41.7 



7.35 

 15.205 



1.5 



Eagle Pass Coal 



0.81 







MINERAL SPRINGS. 



Springs are of very frequent occurrence throughout East Texas. Some- 

 times they are very pure, and almost entirely free from any mineral matter, 

 while at other times they are highly charged with iron, sulphuric acid, and 

 salts of lime, magnesia, alumina, and alkalies. Iron springs, however, are 

 by far the most plentiful of all the mineral waters, and it is an exceedingly 

 common occurrence to see chalybeate waters arising from Tertiary strata. 

 The interstratification of sand and clay beds, representing as they do alter- 

 nate permeable and impermeable layers, is peculiarly favorable to the ex- 

 istence of local springs. Water falls on the sandy surface of a hill and runs 

 down between the loose materials until it meets a clay bed. This proves im- 

 passable on account of its impervious nature, and the water, thus deflected 

 from its downward course, runs over the surface of the clay until it reaches 

 the outcrop of the bed in a hillside or river bluff, and here gushes out as a 

 spring. The ferruginous springs derive their iron from the beds through 

 which they pass. The sandy soils are often bleached on the surface, while 



* Compare First Report of Progress Geological and Mineralogical Survey of Texas, 1888, 

 p. 20. 



