STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 95 



but there are some fine granules, more or less transparent, and occa- 

 sional traces of cell structure. Under water, dopplerite remains un- 

 changed for years. Once dried, it is equally stable ; when wetted 

 again, it may soften so as to show the print of the finger nail, but 

 no farther change appears after several months. 



Muhlberg analyzed four specimens, three from Obburgen and 

 one from Aussee the original locality. In all the carbon is higher 

 while oxygen and nitrogen are lower than reported by Schrotter. 

 The difference was enough to induce Muhlberg to make additional 

 study. The material was treated with caustic potash and the dis- 

 solved substance was analyzed. It is richer than dopplerite in 

 carbon. Kaufmann finds evidence that the varying composition is 

 due to varying extent of change in the vegetable matter. Peat ex- 

 amined in thin slices shows sufficiently well the organic structure 

 but it contains bright specks, soluble in boiling caustic potash ; these 

 are very rare in young peat but are abundant as nests in mature 

 peat. This dissolved material acts as that dissolved from dopplerite. 

 The proportion dissolved by caustic potash increases with the age of 

 the peat, as shown by the following results of Kaufmann's experi- 

 ments : 25 to 30 per cent, from peat directly under the living plants ; 

 54 per cent, at 3 feet below the surface, loose ; 55 per cent, at 6 

 feet below the surface, darker, fibrous ; 65 per cent. 9 feet below the 

 surface, cofi^ee-brown, compact, comparatively heavy. Blackish- 

 brown, heavy, compact peat with black pitch-like streak yielded 

 yy per cent. 



According to Billingsley's^^^ notes, the peat of the South Marsh, 

 3 to 15 feet thick, is accompanied by a pitch-like substance, which 

 occupies the spaces between the vegetable fragments. 



Zincken cites von Tschudi (1859) to the efifect that dopplerite 

 is found in Switzerland near Bad Gonten in Canton Appenzell, 

 where, beyond the depth of 9 feet, it occurs in streaks up to 5 inches 

 thick. Humus acid flows from this and hardens to Pechkohle ; he 

 cites J. W. Herz as authority for this composition of dopplerite : 

 Water, 15.03; ash, 3.39; carbon, 5747; hydrogen, 5.32; oxygen, 



13T Cited by H. B. Woodward, " Geology of Eastern Somerset," etc., 

 1876, p. 156. 



