43 



observations which he will have been enabled to make, he 

 will readily acquire a knowledge of the great leading 

 characteristics of the country, of the value of which he will 

 soon be sensible. 



The lines of junction where dissimilar rocks unite and 

 crop out together, exhibit a soil which is likely to be 

 marked by more fertility than other contiguous lands, not 

 similarly circumstanced. The greater the number of 

 mineral substances a soil contains, it is generally the 

 better. The incombustible remains of plants show how 

 various are the ingredients which vegetable growth ex- 

 tracts from the soil. 



An observer should, however, be prepared to notice many 

 deviations from the general rule, that the character of the 

 soil is determined by the nature of the subjacent formation. 

 When a district is geologically sterile, occasional splendid 

 exceptions are noticed, and rich alluvial soil may be found, 

 of great depth and fertility : this is probably the bed of 

 some ancient river, or a basin filled by the precious deposit 

 of waters that have long ceased to flow. 



Rocks are divided into two great classes stratified and 

 unstratified. The former lie in beds, or strata, one above 

 the other ; the latter exhibit no such appearance of alter- 

 nate layers, but appear in large masses of uniform texture, 

 without any regular stratification. Those primitive rocks 

 sometimes attain a great elevation, and are frequently 

 characterized by their barrenness. The secondary rocks, 

 on the other hand, are more extensively distributed over 

 the country ; and some of them, as the sandstone and lime- 

 stone formations, are distinguished by their fertility. 

 Limestone may be considered the great material selected 

 by the Divine Architect to construct Ireland. It occurs 

 in every county except Wicklow. It is the prevail- 

 ing formation in the central counties, from Dublin to 

 Galway; appears in snowy cliffs along the maritime coasts 

 of Antrim, as the dark-coloured calp of county Dublin, 

 and furnishes marbles in Kilkenny, Armagh, Galway, 

 Carlow, &c., in every variety of shade and beauty. 



