166 . III. DIST. CHAR. Soil. 



also., are sometimes continuous or unstratified. Soil* 

 of this description seldom contain organic remains. 



B. 135. A STRATIFIED SOIL (Solum stra- 

 tarium) is divided into beds or strata. 



The soils of this division are either regularly or 

 irregularly separated into beds. 



Regularly (regularitcr) when the strata preserve 

 their parallelism and, consequently, their respective 

 thicknesses, throughout the extent of the soil which 

 they collectively form. 



Irregularly (irregular it er) when the parallelism 

 of the strata is not preserved. This may arise from 

 the diminished or increased thickness of the beds, in 

 particular parts of the soil and, sometimes, from 

 the difference which takes place in the dip and 

 course^ of the strata. 



Obs. Stratified soils consist either of one species 

 of stone, separated into strata by seams ( semi-strata ) 

 of clay or other matter ; or, of beds of various sub- 

 stances alternating with one another ff. 

 c. Materials. 



According to which the soil is either calcareous, 

 argillaceous, or siliceous. 



A. 136. A CALCAREOUS SOIL (Solum cal- 

 careum) is one in which the chief mass of its earths 



f Vide p. 170. note. 



\ f Mountains which consist of one kind of stone are called, 

 by Kirwan, unigenous ; those formed from strata of different sub- 

 stances, potygenous. 



