THE VEGETABLE MATTER OF ILLINOIS COAL BEDS 761 



larger proportion of fixed carbon than the bright bands. A number 

 of proximate analyses of mineral charcoal compared with those 

 of average coals from the same beds are given in Table I. It will 

 be seen from this table of analyses that the mineral charcoal 

 generally contains but little, if any, more ash than the average 

 coal of the bed in which it occurs. 



TABLE I 



f'ROxiMATE Analyses of Mineral Charcoal and Average Coals from the 



Same Seams 

 {a) Charcoal Samples; (5) Average Samples 



Water 



Volatile 



Matter 



Fixed 

 Carbon 



Ash 



Ash in Charcoal 



above or below That 



in Average Sample 



Iff. 

 ll). 

 2a. 



2b. 



3b. 

 4a. 

 4b. 

 Sa- 

 5b. 

 6a. 

 6b. 

 ya. 

 7b. 

 8a. 

 8b. 

 ga. 

 9b. 



19.77 

 39.26 

 20.36 

 37.80 

 12.40 

 34-97 

 14-32 

 28.01 

 9.92 

 16.85 

 88.36 

 20.76 

 20.98 

 17. II 

 10.49 



17-85 

 23.96 



34-91 



72.13 



55-83 

 71.07 

 54-46 

 75-34 

 57.00 

 64.03 

 49.24 

 81.37 

 69-58 

 87-64 

 71.70 



70-37 

 70.74 

 84.01 



72.15 

 64.28 

 52-03 



6-93 



2. 24 



7.82 



4-78 



9.87 



5-67 



21.13 



17. 21 



8.16 



10.13 



3-15 



5-33 



8.08 



10.60 



4-65 



8.39 



10.18 



10. 72 



+4 

 +3 

 +4 

 +3 

 — I 



Nos. 1-8, analyses by McCreath, Second Geological Survey of Pennsylvania, Vol. MM, pp. 1-107; 

 moisture at 225 degrees F. 



No. 9, analyses Illinois Geological Survey, Herrin (No. 6) coal, Williamson County, Illinois; mois- 

 ture air-dried. 



After discussing the original amount and the composition of 

 the ash contained in living species of such types of coal plants as 

 lycopods, ferns, and equiseta, Stevenson^ concludes that "one should 

 expect to find in ordinary [pure] coal not much less than 6 per cent 

 of ash, or even more, in which silica and alumina should predominate 

 greatly." He thinks it probable that coals containing less inor- 

 ganic matter than the plant substance should have yielded have 



^ J. J. Stevenson, "The Formation of Coal Beds," Proc. Am. Phil. Soc, LII 

 (1913), 107. 



