274 THE IRON ORE DISTRICT OF EAST TEXAS. 



sand marl in the valleys of the lower part of Nacogdoches County, which is 

 overlaid by only a light covering of detritus from the adjacent hillsides. 

 When no such absorbent lay in the course of the oil it was carried by the 

 rivers to the sea. Ex Governor 0. M. Roberts' " Description of Texas" calls 

 attention to floating oil on the Gulf of Mexico near Sabine Pass, the natural 

 outlet of this region. 



The origin of this oil appears to have been in the lignite bed, for similar 

 oil may now be seen exuding in small quantity from the lignite and floating 

 as film on adjacent ponds and streams. The writer is of the opinion that it 

 has been produced by the gradual decomposition of vegetable matter alone. 

 This seems to be supported by the fact that no animal fossils were observed 

 in immediate association' with the lignite bed. No doubt that the decomposi- 

 tion of animal remains have in other formations contributed their quota of 

 oil, as claimed by Dufrenoy (Mm., iv, 602, 1859), J. S. Newberry (Ohio 

 Agric. Rep., 1859), and T. Sterry Hunt (Can. Nat., vi, 241, 1861; Amer. 

 Jour. Sci., ii, xxxv; Chem. News, 1863). 



fflgpffl^ . -_ 



Fig. 22. 



IDEAL SECTION OF OIL BEARING REGION IN NACOGDOCHES COUNTY. 



a, Iron ore hilL b, Lignite bed. c, Detritus, d, Oil bearing greensand marl. 



The oil is of brown color, similar to oil of tar, and contains a mixture of 

 several liquid parafins. It has been exposed and transported some distance 

 from its source by the agency of water, which will account for the loss of 

 nearly all the naptha and probably all solid paraffins. 



Both liquid and solid paraffins are produced by the oxidation and distillation 

 of organic matter, such as wood, brown coal, peat, bituminous coal, bituminous 

 shale, fatty oils, resin, and animal matter. Richenbach, in 1830, discovered 

 in wood tar a mixture of the paraffin series, and on account of its little affinity 

 for other substances he gave the solid members the name (from parum and 

 affinis). By fractional distillation he obtained a mixture of the liquid mem- 

 bers, which he named eupion. 



Most carbon compounds yield some member or a mixture of the members 

 of the paraffin series when heated with an excess of hydriodic acid. (Berthe- 

 lot, Ann. Chem. Phys. (4), xx, 392.) Cast iron when dissolved in acid pro- 

 duces a hydrocarbon containing paraffins. (Cloez, Compt. Rend., lxxxv, 1003.) 



Pennsylvania mineral oil consists mainly of the normal paraffins with a 



