:274 ON THE FORMATION OF ROCKS. (June> 



19. Hock' Salt, including all the attendants of Clay-beds, 

 Gypsum, Sandstone, &c. 



20. Gypsum, horizontally stratified, including Clay, Sul- 

 phur, Crystals of Quartz or Aragonites, &c. &c. in 

 which no remains of organic matter may yet have 

 been found. 



21. Sandstone, with an ochry, ferruginous cement, called 

 by Werner, Rothe tode Liegend, with all its accom- 

 panying stratifications of limestone, thin strata of Coal, 

 Gypsum, &c. &c. having organic matter disseminat- 

 ed, though rare. 



The above rocks are gefterally stratified horizontally, 

 qr following the dip or inclination of those on which they 

 rest, but lying deep under the surface, and their period 

 of formation, prior to the date of our observations, prevents 

 their mode of aggregation from coming within the obser- 

 vation of our senses; and must depend on rational or posi- 

 tive analogy. 



22. Graywacke, rolled masses of rocks cemented by a 

 clay slate, more or less apparent, or by a slaty fibrous 

 cement, having some resemblance to a Chlorite Slate: 

 the last mentioned generally found near the primitive. 



23. Graywacke Slate, small rounded particles of rocks, 

 enveloped in a slaty base, accompanied and alternat- 

 ing with Calcareous Shist, &c. &c. 



24. Sandstone of transition, fine grained, having general- 

 ly a siliceous cement: in the fresh fracture, resembling 

 quartz, but in a state of decomposition the granular 

 texture appears. 



25 y Limestone of transition, generally a small crystalline 

 grainj with small veins and seams of calcspar, hav- 



