196 CAUSE OF DISEASE AMONG 



in its native localities, I never could satisfy myself 

 as to the cause of the disease which has appeared 

 among the larch plantations in Scotland ; but 

 since I have been made aware of the above circum- 

 stances, and have compared them with examples of 

 healthy and unhealthy plantations upon several 

 estates, where I have had the opportunity of ex- 

 amining for myself, I am now perfectly convinced 

 as to the cause of the chsease in question ; and I am 

 further convinced, that any man who will compare 

 the state of the ground upon which a healthy plan- 

 tation of larch is found in Scotland (that is to say, 

 one which has arrived at a considerable age, and is 

 in a sound state) with what I have stated relative 

 to the healthy state of trees of the same species as 

 found in their native regions, will at once see the 

 same circumstances acting in each case. Thus : — In 

 all cases of healthy larch plantations in this country, 

 where the timber has attained large size, and is sound 

 in quality, we find them growing upon a soil through 

 which the water that may fall upon it can pass away 

 freely ; as for instance, upon the slopes of hills, and 

 even in hollows, upon a strong clay soil, but where 

 there is a proper drainage for the ready and free 

 passage of the superfluous water ; and I have even 

 cut down larch timber, of large size and sound in 

 quality, growing upon a light sandy moss, two feet 

 deep, which rested upon a stiff clay. In this case 

 the moss was drained, and the water passed freely 



