170 . Ill, DIST. CHAR. Soil. 



b. 154. MINERAL SEATS (Seeks minerales) con- 

 sist of mineral matter, and are distinguished accord- 

 ing to their structure and materials. 

 * In structure, 



The mineral seat is either a mass, stratum, or 

 rift. 



A Mass ( Massa) is a body of earth, stone, &c. 

 having no determinate or regular extension. 



Obs. The mass is not the seat in which extrane- 

 ous fossils are usually lodged, but they sometimes 

 occur in it. 



A Bed or Stratum f (Stratum ) is a body of 

 earth or stone, &c. in length and breadth indefi- 

 nitely extended ( mostly in an horizontal or inclining 



Germany, Italy, &c. &c. are also noted for this formation. Mr. 

 Kirwan, however, justly remarks, that " everal lakes, or other 

 waters, that anciently possessed a petrifying power, have since lost 

 it, by having imparted the greater part of the stony particles they 

 contained to such substances as were capable of retaining them.'' 

 G. Ess. p. 14. 



f* Many geologists of the Weraerian school use the terms beds 

 and strata with the following distinction. Beds, when the soil 

 consists of different substances alternating with each other. Stra- 

 ta, when the soil, though divided into beds, is composed only 

 of one species of stone, or other mineral substance. We do not, 

 however, see the utility of this discrimination ; and in one case, it 

 evidently produces a confusion in the use of the term stratified, 

 or necessarily limits its employment to descriptions of unigenom 

 soils ; since it would certainly be improper to call a mountain, or 

 other extent of soil, stratified, in which no strata, according to 

 the above distinctions, were present. 



