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is well known to be extremely common ; 

 and trees, usually esteemed the most 

 beautiful, are most of all subject to this 

 sort of decay ; of course, the subject de- 

 serves more than ordinary attention. 



l^he first remark which offers is, that 

 the defect is much more common to hard 

 woods than to such as are softer. The 

 reason seems to be, that their sap-vessels 

 are commonly larger ; and, therefore, the 

 ascent of the sap through them is not ea- 

 sily obstructed. 



Again. Trees growing singly are much 

 more liable to the defect, than such as 

 grow in consort; the former being subject 

 to produce branches thickly set, while the 

 latter must, from their confined situation, 

 form them much thinner. The defect in 

 this case, then, may be easily traced to 

 the branches too closely besetting the 

 stem, and thereby intercepting the greater 

 proportion of sap, in its ascent ; — in con- 



