300 SIR HENRY STEUART'S METHOD 



should possess the following qualities ; first. Thick- 

 ness and induration of bark ; secondly, Stoutness 

 and girth of stem ; thirdly, Numerousness of roots 

 and fibres; and, four thly. Extent, balance, and 

 closeness of branches. These Sir Henry Steu- 

 art has designated Protecting Properties, and the 

 i^ationale which he gives of them is in substance as 

 follows. 



Thickness and induration of bark are absolutely 

 necessary for every tree that is to be placed either 

 single, or in a small group, in order to defend 

 its sap-vessels from the injurious effects of cold. 

 This principle is deduced from the circumstance, 

 that Nature, who does nothing in vain, gives to all 

 exposed trees a much denser and harder outer coat 

 than to such as have the advantage of shelter from ex- 

 ternal objects. Thus, on examining a single or an ex- 

 posed tree, we always find that its bark exceeds both 

 in thickness and induration that of another of the 

 same age and species, in the heart of a large planta- 

 tion, where closeness of shelter renders it unneces- 

 sary that the tree should be provided mth the 

 means of self- protection independently of foreign 

 aid. Hence we may easily see the folly of remov- 

 ing a tree to an open situation, from a closely shel- 

 tered one, nature having never qualified it for such a 

 change. 



