202 STEVENSON— INTERRELATIONS OF THE FOSSIL FITELS. 



wholly similar material were observed by D. White at Hoyt, Texas ; 

 the same observer has described the cannel-like material of the 

 Lester bed in Arkansas, very rich in oils and in gas of high candle- 

 power; it is rich also in spores and pollen exines. Tertiary "oil 

 shale" of high grade is reported from New Zealand. The mode of 

 occurrence and the chemical as well as physical constitution indicate 

 very close relationship to the Lebertorfs. Pyropissite presents some 

 problems not yet wholly solved, though they have attracted attention 

 from many students ; but there appears to be little evidence to sup- 

 port the hypothesis that it is merely the resin of the original plants, 

 concentrated by physical agencies during transportation of the more 

 or less converted peat or brown coal ; while there is much to suggest 

 that it is related to the Lebertorfs. The condition is different in the 

 case of dysodil or Blatterkohle ; that is without doubt of sapropelic 

 origin. It occurs in lenses, sometimes at the bottom, at others in the 

 upper portion of a bed, while, occasionally, it forms the whole mass. 

 This contains abundant remains of aquatic animals, spores, pollen 

 and, at times, is rendered almost worthless by the great proportion 

 of diatomaceous earth. 



Haidinger, in studying the Faserkohle from the Haring deposit, 

 discovered that it contained a material, which he believed was intro- 

 duced when in the condition of dopplerite, a soluble constituent of 

 peat; D. White in several publications has maintained that the jeti- 

 fied wood, so abundant in the xyloid Tertiary coals of the United 

 States, owes its character to the infiltration of dissolved products of 

 vegetable decomposition. Glockner reached the same conclusion re- 

 specting the "Glanzkohle" of Zittau. Von Giimbel regarded the 

 " Carbohumin " or cementing material of brown coal as merely dop- 

 plerite which had passed over to the insoluble condition. Doppler- 

 ite, as the analyses show, is not a true mineral but is a mixture of 

 various humic or humic and ulmic compounds, which after losing 

 an indefinite proportion of water, is so changed that it cannot regain 

 plasticity even by prolonged submergence in water. The zittavite 

 of Glockner appears to be a wholly similar substance; the terms 

 dopplerite, Carbohumin and zittavite indicate the geological horizons 

 of the occurrence. 



