248 GEOLOGY OF ILLINOIS. 



this county is extracted from Dr. BLANEY'S Chemical Report, in Yol. 

 I, page 276. The specimens were collected in 1858 from mines worked 

 at that time, and -the owner's name was given instead of the locality 

 where the mines were located. The two first are an average of three 

 analyses of specimens from different parts of the seam at one locality, 

 and the last the result of only a single analysis : 



Aiken's Mine (Coal No. 4.) 



Specific gravity 1 . 3122 



Total volatile matters 36 . 9 



Coke 63 1 



100.0 

 ANALYSIS : 



Moisture 103 



Volatile combustible matters 29 . 9 



Carbon in coke 54 . 4 



Ashes 8-7 



103.3 

 R. Howard's Mine (No. 6.) 



Specific gravity 1 . 2571 



Total volatile maters 38 . 3 



Coke ... .. 61.7 



100.0 

 ANALYSIS : 



Moisture 11 . 2 



Volatile combustible matters 27. 1 



Carbon in coke 59 . 5 



Ashes 2.2 



100.0 

 Specimen from Isaac Brown's land (Seam No. 7.) 



Specific gravity 1 . 3228 



Total volatile matters 37.2 



Coke .. .. 62.8 



100.0 



ANALYSIS : 



Moisture 12 



Volatile combustible matters 25.2 



Carbon in coke 53 . 2 



Ashes . 9.6 



100.0 



These analyses show that No. 6 contains the largest amount of fixed 

 carbon, and the smallest amount of ashes, while the specimen from No. 7 

 contained a smaller per cent, of carbon and more ashes than either of 

 the others. However, the actual value of this coal cannot be fairly 

 judged from the result of a single analysis. At least three-quarters of 

 all the coal mined in the county at the present time is taken from No. 4, 

 and the others are only worked in neighborhoods where No. 4 is below the 

 surface, except at some few points where No. 6 is mined in a small way 

 for smith's coal. No. 6 is more irregular in its development than either 

 of the others, and for this reason it is generally neglected. When fully 



