TREATMENT OF WOUNDS 43 



as to disturb the moist surface of the wood as little 

 as possible. In two or three weeks it will be easy 

 to see whether the operation has been successful. 

 The surface will have grown outward perhaps an 

 eighth of an inch, and scratching will disclose a 

 pulpy greenish layer spread over it. It will not 

 of course be present where the wood itself has 

 been scraped or bruised. The cambium can be 

 saved in this way with most uniform success in the 

 growing season. 



If the bark wound has not been attended to at 

 once it should first be inspected to see whether any 

 part of the cambium has escaped drying out and 

 has started growing a new bark. Such areas should 

 of course be preserved, unless they are detached 

 tongues of the kind which has been described as 

 being too remote from the line of sap flow. In 

 that case they had better be removed, for they 

 retard healing more than they help it. The first 

 thing to do with an old bark wound is to clean 

 it up thoroughly. Clear away all dead and 

 shredded bark. Sound the exposed wood with a 

 chisel or by boring into it, if necessary. If the 

 wood is much decayed it may have to be filled in 

 one of the ways to be described in a later chapter. 

 A depth of decay of only an inch or two, however, 

 or perhaps three or four inches, if it is a large 

 wound, needs only to be cleared entirely away. 

 If the resulting excavation extends under the 



