128 TRANSACTIONS OF THE ILLINOIS 



determine if they couid be used as a material from which to obtain oil or 

 illuminating gas, and found them to contain as follows : 



CINCINNATI SHALES WHITNEY. 



Volatile combustible matter 14.12 



Fixed carbon 6.84 



Incombustible residuum 78 29 



Moisture 75 



100.00 



He states that the residuum consists of mainly a silicious shale, highly 

 impregnated with bitumen. (Iowa Rep., vol. I, fol. 359.) Shales, as a 

 rule, are generally unfertile ; they form a cold, wet, close soil ; the shales 

 in question are no exception to the rule. In the cut made by the I. C. 

 R. R., at Scales Mound, twenty years ago, about forty feet in thickness 

 of these shales were thrown out. The pile is there to-day, ten to fifteen 

 feet deep, fifty feet wide, and one thousand feet long ; nothing grows 

 upon it ; it is as bare of vegetation as the rock-pile on the north side of 

 the cut. It contains no plant food. 



The Galena limestone is a Magnesian limestone, containing carbon- 

 ate of lime, 43. ; carbonate of Magnesia, 39.40; silex, 14.50; aluminia 

 and loss, 3.10. 



Prof. D. D. Owen, in his report to U. S. Doc. 407 — I have ana- 

 lyzed with care the soils of the mining region. The specimens 

 were taken from localities widely apart, from six inches below the 

 surface, with one exception, from wild lands. The analysis of the fifteen 

 specimens are given separately by Doctor Owen. We have combined 

 them, and give the average : 



SOIL FROM MAGNESIAN LIMESTONE REGION. 



Organic matter (soluble) in Alkali 4.80 



" " (insoluble) " 5.13 



Salts of Lime, Magnesia, and Aluminum 3.70 



Salts of Alumina and Iron i.oo 



Silicic eous residuum 82.50 



Loss by baking 2.87 



100.00 

 Specific gravity, 1.84. 



Prof. Owens states that the soluble portion of organic matter is sup- 

 posed to be that which is already prepared to become food tor plants. 

 The insoluble portion is that which, by the action of water, air, and other 

 influences, will become so. Thus the amount of soluble organic matter 

 in the analysis is that which indicates present fertility, and that of insol- 

 uble organic matter that which measures durability of soil. The conclu- 

 sions drawn from the above analysis of virgin soil, thirty years ago, have 



