QUALITY OF WASTE LAND. 119 



trable to drain, the alder and the indigenous species 

 of willows are the proper kinds. Where the sur- 

 face water can be got clear of, the spruce and silver 

 fir intermixed with birches, and here and there a 

 larch, will be found to answer best. These may in- 

 deed be considered as the most profitable for wet 

 land, whether the soil be good or bad. 



I may notice here, though the remark would have 

 more properly appeared in the preceding chapter, 

 that there are many mineral productions which are 

 unfavourable to the growth of timber. To say no- 

 thing of iron and lead ore, the latter of which, es- 

 pecially, is well known to be unfriendly to vegeta- 

 tion in general, few kinds of trees will grow freely 

 where slate abounds. An exemplification of this 

 remark may be seen near the slate quarries, in the 

 Parish of Culsalmond, Aberdeenshire. Freestone 

 especially, when it lies near the surface, is likewise 

 inimical to the production of wood. The same is 

 perhaps true of most of the minerals that occur in 

 Scotland, with the exception of limestone, whinstone, 

 and granite ; terms which, as they are commonly 

 used, comprehend a number of rocks, to which mi-= 

 neralogists give other names, 



