Cornirall, Devon, and Wed Somerset. 29 



the southern shores of Cornwall by the Looes, Fowey, Veryan, 

 and Falmouth, to the northern part of the Lizard district, may be 

 considered, upon the whole, the most fertile part of the Cornish 

 and South Devon grauwacke, especially the more eastern part 

 between the Tamar, Torbay, and Newton Bushell.* Other minor 

 areas, no doubt, afford equally good land ; as, for instance, the 

 vicinity of Penzance, a tract, the superior fertility of which has 

 been pointed out by Dr. Paris, and correctly referred by him to 

 the decomposition of the greenstone rocks which there abound. 

 He states that, when he wrote (1818), a belt of land around that 

 town, of 1000 acres, produced an annual rent of 10,000/.f 



The mining districts have often a very barren aspect, inde- 

 pendently of the destruction of vegetation produced by mining 

 operations on the surface. We have frequently found the ground 

 covered, in such situations, by a thin bed of quartz fragments, 

 composed apparently of the parts of those minor veins which often 

 abundantly traverse such countries in different places. It would 

 appear as if, during the decomposition of the general surface by 

 meteoric influences, and the removal of the finer particles of 

 the slates by rains, these fragments had gradually accumulated 

 on the surface, rendering it even less fertile than it would other- 

 wise he. 'I 



Judging from the Lizard, the soil on the serpentine is far from 

 fertile, frequently retaining the water on its surface, so that 

 swamps and marshy places are common. Even on the slopes of 

 the hills, where the natural drainage is good, little can be said for 



* A portion of this rock, near the Tamar, between Tavistock and Laun- 

 ceston, where it is called SkiUot, affords a soil of singular fertihty, the grass- 

 lands yielding; often from 2 to 3 tons of fine hay, principally consisting of 

 white clover. On the pasture it is affirmed that an ox will, from being 

 quite poor, get moderately fat in ten weeks. As arable land, many parts are 

 too forcing for the growth either of wheat or potatoes. An exact analysis of 

 the soil and subsoil of this district would be very instructive. The agri' 

 culturist must study the constiiution of his patient the soil, if he would 

 understand where its strength or weakness lies. — F. Falknkr. 



t Observations on the Geological Structure of Cornwall, with a view to 

 trace its connection with and inlluence upon its Agricultural Economy, and 

 to establish a rational System of Improvement by the scientific application 

 of Mineral Manure. — Trans. Geol. Soc. of Cornwall, vol. i., p. 188. 



% Quartz is commonly linown by the name of 5par in western Cornwall, 

 and as ivhiteacre in eastern Cornwall and part of Devon. Mr. Worgan, 

 noticing the loose quartz fragments of various sizes dispersed over the sur- 

 face in many parts of Cornwall, and that it may be sometimes profitable to 

 remove them, states, that "Mr. James, of St. Agnes, cleared a large field of 

 spar, by screening the whole mass of spar and earth, as deep as the yellow 

 substratum, in the same manner as masons screen the earth for their mor- 

 tar ; and the experiment answered well, although it cost 40/. per acre : the 

 land was afterwards let for 3/. per acre, and the stones were purchased to 

 make a road." (View of the Agriculture of Cornwall, p. 11.) 



