188 THE PRACTICAL PLANTER. 



culable number of places, from the ground 

 upwards ; and also, that the trees are never 

 afflicted with the worm until they become sickly 

 from another cause. 



This cause undoubtedly rests in the soil. 

 For, in one instance of investigation, where 

 a whole stripe of Scotch Firs, except the outer 

 row on one side, were in a state of decay, 

 and wormtd; I found this row of healthy 

 trees standing on a bank of free, gravelly, 

 loose mould, and the others languishing on 

 a thin turf, with a wet, tilly bottom. Where- 

 fore, the cure for this disease is obvious,* 



* Since writing the above, I have learned a curious 

 fact respecting this matter. Some years ago, many Scotch 

 Fir-trees, of considerable magnitude and value, belong- 

 ing to the Earl of Leven, in the county of Fife, were ob- 

 served suddenly to decay ; and in the course of a year 

 or two, to become quite leafless I 



They were found to be wormed, and to waste apace 

 on their limbs ; much faster than felled timber does 

 when suffered to lie among rank herbage, &c. Yet the 

 soil on which the plants stood is a gravelly sand, and the 

 sub-stratum a loose rubble ! Stagnation of air has been 

 supposed, and with great probability, to be the cause of 

 this disaster ; as the plantation was much neglected in 

 respect of timely thinning. The situation is low, and 

 lies in the wane of a marsh (formerly a lake) from whence 

 much damp and fogs have been observed to rise. 



