ON QUxVLITY OF SOIL. 



107 



black earth is most suitable for them, but they 

 may be planted with success in stiff lands of a good 

 quality. Two species have already been mentioned; 

 the one with a broad scented leaf, of a shining green 

 colour ; the other with woolly leaves, a greyish bark, 

 and, in spring, bearing a large catkin. These are 

 the kinds which are proper for the sour stiff mo- 

 rasses that so often occur in our waste lands. If 

 the golden, or the Huntingdon, or any other of the 

 finer species of willows, be planted in such situa- 

 tions, they will scarce live, much less make any pro- 

 gress in growing. 



All the Poplar tribes will thrive in the same qua- 

 lity of land with the finer species of willows, or, if 

 there be any exception to this, it is, that the white, 

 or Lombardy poplar, is less fond of moistui'e than 

 the rest, and will attain a good size even where the 

 soil deserves the epithet of dry. Unless the aspen, 

 which is a native of Scotland, none of them will 

 come to perfection, but in a tolerably rich soil. The 

 sides of streams, and places where the land is of an 

 alluvial nature, are most proper for almost all the 

 foreign species of poplar. But the aspen, or quaking 

 ash, as it is sometimes called, will thrive on very 

 dry and barren land, and at a great elevation. On 

 the estate of Abergeldie, there is a hill more than 



