INTRODUCTION. 131 



lutely correct, for there are soils here and there to be 

 found, though comparatively rare, capricious enough 

 to refuse even to grow this proverbially hardy tree. 

 It is, however, usually on account of the excessive 

 richness or hardness, and not the poorness of the soil, 

 that the tree refuses to grow in it. 



Thinning is a lever in the hands of the forester of 

 immense power and importance, by which a crop of 

 Scots pine may be made profitable or unprofitable, good 

 or bad, according as that power is exercised. 



It is still far from being universally known, that 

 although gravel, sand, and dry soils generally are the 

 best and most adapted to its growth, yet upon such 

 soils, where the best crop should be grown, the very 

 opposite results are often brought about, through in- 

 judicious and inopportune thinning. The writer could 

 point to hundreds, if not thousands, of acres of Scots 

 fir plantations in Scotland where the market value, no 

 less than their other worth, has been diminished by 

 from one-third to one-half, and in some cases consider- 

 ably more, simply on account of thinning being done 

 at the wrong time. The terms injudicious, improper, 

 inopportune, and suchlike, though familiar to the ear, 

 yet convey no definite or distinct idea, nor point out 

 what should or should not be done by way of thin- 

 ning ; and therefore it is all the more necessary that 

 we should endeavour to make the subject as clear and 

 plain as possible. 



One principal reason why thinning is rendered such 

 an immense power for good or evil, is in consequence 

 of the change of temperature it produces upon the 

 soil. When trees are planted in their young or seed- 

 ling state, they, like most other things when young, 

 readily adapt themselves to their circumstances such 



