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whose sap is characterized by abounding in astringent 

 or mucilaginous constituents, it is usually attended 

 by a sanious discharge. In such instances, it might 

 strictly be designated ulcer, or Gangrcena saniosa. 

 This disease has a considerable resemblance to the 

 tendency to ossification which appears in most aged 

 animals, arising from their marked appetency to se- 

 crete the calcareous saline compounds that chiefly 

 constitute their skeletons. The consequence is an 

 enlargement of the joints, and ossification of the cir- 

 culatory vessels and other parts, phenomena very ana- 

 lagous to those attending the cankering of trees. As 

 in animals, this tendency is general throughout their 

 system ; but, as is observed by Mr. Knight, " like 

 the mortification in the limbs of elderly people," it 

 may be determined as to its point of attack, by the 

 irritability of that part of the system. This disease 

 commences with an enlargement of the vessels of the 

 alburnum of a branch, or of the stem. This swelling 

 invariably attends the disease, when it attacks the 

 apple tree. In the pear the enlargement is less, yet 

 is always present. In the elm and the oak sometimes 

 no swelling occurs ; and in the peach we do not recol- 

 lect to have seen any. We have never observed the 

 disease in the cherry tree, nor in any of the pine tribe. 

 The swelling is soon communicated to the wood, 

 which, if laid open to view on its first appearance, by 

 the removal of the bark, exhibits no marks of disease 



