46 Mr. Arthur Deane on 



or tannins, gums, resins, or mineral matter, whicli serve as 

 cifectual preservatives a,uainst dccaj'. The colour often determines 

 ([uality, for instance, the darker the heartwood of Larch, the 

 greater its durahility. Heartwood is heaviei- than the sapwood, 

 which is less durable because the living cells of the sapwood 

 contain stareli and other organic foods, and therefoi'e this wood 

 is more liable to suffer from rot, I'csnlting from the attacks of 

 wood-destroying fungi. 



Although not so durable, sapwood is moi'e pliable than 

 heartwood and the sapwood of some trees, such as Hickory and 

 Ash, are valued for their bending quality. 



In some trees there is no difference in colour l)etween the 

 "heart" and sap" as shown i)i the old Oak stump, but in these 

 cases, the "heart," if present, can frequently be distinguished by 

 its relative dryness which would become obvious on microscopic 

 investigation. The living elements of the sapwood (rays and 

 soft tissue) lose their living contents when the wood becomes 

 changed into heartwood. Such trees having no distinction 

 between "heart" and " sap " are more likely to become hollow 

 than trees having a coloured heartwood. That the absence of 

 heartwood will not kill a tree, or that its presence is not even 

 necessary for its life, is proved by the many hollow trunks, 

 bearing in summer a healthy crop of leaves, the only disadvantages 

 such trees suffer are want of firmness and stability. 



In heartwood trees the more "heart" the better the wood 

 when used as timber, and the presence of only a little, or its 

 absence, is a sign that the wood has been cut from a young tree. 



It must not be supposed that all trees possess heartwood. 

 Many trees have no heartwood, but all trees without exception 

 must have sapwood, as they could not live without it, seeing 

 that it is the path travelled by the water containing mineral 

 matter in solution from the roots to the leaves, there to be 

 elaborated and manufactured into food. Until that has taken 

 lilace, this solution could not be used for the growth of the tree 

 any more than it could be used as food by a man. The heart- 



