CULTIVATION OF PARSNIP. 407 



and where the parsnip has not as yet beerf intro- 

 duced. If other circumstances (the method of 

 culture, the deep ploughing required, and the 

 nature of the soil necessary for this root) do not 

 prevent its introduction into the Highlands, it 

 may eventually be found a valuable substitute 

 for the potato, in many situations where the ear- 

 ly frosts often destroy that plant long before the 

 tubers have arrived at maturity. It is no small 

 additional merit, that it is nearly exempt from 

 the attacks of insects ; and from the diseases in- 

 cident to all our esculent roots, as well as from 

 the effects of cold. In wet springs only, it is 

 remarked, that the plants in Guernsey are some- 

 times destroyed by slugs, and that extremes of 

 dryness or m6isture protracted through the sea- 

 son, are injurious to them. 



The superior quality and size of the root in 

 Guernsey, appears to be the result of the long 

 continued care and attention bestowed on it, since 

 there is nothing in the soil of that island, to ac- 

 count for this difference ; and since that soil it- 

 self is by no means of a very superior quality. 

 The greater part of the island consists of a large 

 foliated gneiss, impregnated with a considerable 

 proportion of iron, and subject to decomposition 

 in the mass, by a process of rotting or gangrene 

 similar to that which occurs in many varieties of 

 the trap family, and among other places very 

 remarkably in Sky. The result is consequently a 



