J68 & III. DIST. CHAR. Soil 



d. Particular Products. 



According to which the soil is said to be 



A. 149. CARBONIFEROUS (Solum carboni- 

 ferum ) bearing or producing coal. 



B 148. FERRIFEROUS ( Solum ferriferum) 

 producing iron. 



&c. &c. 

 c. Parts. 



The parts of the soil, which have immediate rela- 

 tion to extraneous fossils, are the tract) seat, and 

 matrix. 



A. 149. THE TRACT ( Tractus} is the super- 

 ficial part of the soil forming in some determinate 

 extent on the earth 's surface. 



A tract is distinguished according to the soil 

 of which it is a part (v. p. 155.) ; and as being 

 either general or partial. 



a. 150. A GENERAL TRACT (Tractus generalis) 

 is one which runs through a large extent of country, 

 and is bounded by several tracts of a different 

 nature. 



b. 151. A PARTIAL or INCLUDED TRACT (Tractus 

 inclusus} is generally of small extent, and always 

 inclosed or surrounded by one tract only, of a dif- 

 ferent kind. 



Obs. Carboniferous soils often form partial tracts: 

 the rock on which they have been deposited rising 

 on all sides of the coal land, and constituting its 

 boundary by a circular tract of one formation. 



