MINERALOGY OF ST ANDREW'S. 146 



passes distinctly into sandstone, by acquiring small 

 portions of mica and quartz. It likewise passes 

 into limestone and bituminous shale. It includes 

 thin layers of sandstone, and often contains ve- 

 getable impressions. 



I think it proper in this place to mention a fact 

 not generally known, That slate-clay forms a ferti- 

 lizing manure to sandy soils, by supplying the re- 

 quisite portion of aluminous earth. In the neigh- 

 bourhood of Kirkcaldy, there are several fields of 

 sandy soil which rest upon sandstone. To these 

 fields, slate-clay and bituminous shale have beeri 

 applied as manure, and with success: they were, 

 previous to this application, unproductive ; they 

 now yield good crops of grain and grass. To the 

 west of St Andrew's, there are extensive tracts of 

 soil, principally composed of sand. VV'^ere the 

 slate-clay, so abundant among the rocks in the 

 neighbourhood of the city, spread upon these 

 grounds, the most beneficial effects would result 

 from the application. The ground would become 

 firmer, the soil more retentive of moisture, and 

 better able to resist the drought of summer. Ig- 

 norance and prejudice may prevent some from 

 following the example of the farmers in the 

 neighbourhood of Kirkcaldy ; but I have no hesi- 

 tation in asserting, that its imitation in many 

 places of the coal districts of Scotland, where 

 such soils and such rocks abound, would greatly 

 eontribute to increase the food of man and beast. 



K 3 



