“1492. ‘on planting. ° 16% 
-Jarix, the most beautiful, and useful tree, as well as 
the quickest grower, we Know; and therefore very, 
generally propagated. I have asmall plantation made 
by myself of that tree, which is now exactly nine 
years old, most of the trees of which, are about 
“twenty feet in height. Trees, therefore, are reared 
here in great abundance ; and thrive as well as per- 
haps in any climate equally distant from the torrid. 
zone. 
We ‘are not, in Scotland, surprised at finding tree 
seeds spring up on the tops of houses, or on ‘barren 
-soils we know well that it is on barren soils alone 
that ever tree seeds can~spring up spontaneously. 
No plant is so very. destructive to seedling’ trees as 
-grafs ; and wherever grafs spontaneously grows up- 
on the surface, self sown trees never will spring up. 
If the soil be so bare as to yield no grafs, and very 
‘little heath, trees will get up if the seeds be within 
reach; especially those with light seeds, like the 
-birch or fir; for there the plants eome-up; nor are 
»eattle or wild animals tempted to brouse upon them. 
But if a pile of grafs appears, if that be not eut down, 
‘it soon increases, grows: thick, covers the young 
plants in summer, and in winter it falls down and 
»rots, suffocating the young trees. Even planiat ons 
> made on such soils often fail ; for if the trees be large, 
‘they frequently die down ; and if the plants be smal¥ 
“they are overtopped by the grafs.and smothered. 
An extensive heath is the kind of soil: that admits of 
_being easiest stocked with trees by planting. A 
‘naked thin soil, that neither carries heath nor grafs, 
will soon become covered with young plants of birch, 
“WOL. ix. x 
