86 



THE MONTHLY BULLETIN. 



living bark and sound wood, («) cracks extending into the main limb 

 from the dead stub. 



Fig. 25b shows the just-described limb after treatment. In this 

 figure (»■) represents the depth to which the wood was cut out to reach 

 sound wood. The region (p) is a heavy plaster of Bordeaux paste 

 applied to the depths of the cavity to act as a disinfectant, The cement 

 filling (q) is set firmly against the wood at (s). The face of this cement 

 filling is well below the bark layer so that the new bark can grow out over 

 its surface and so hold the filling tightly in place. The (7i) indicates the 

 usual asphaltum wax coating over the cut edge of the living bark. 



Considerable skill is required to make such a filling, and the proper 

 technique is only acquired after practice. The first step is to cut a deep 

 line around the edge of the living bark with a chisel. The chisel cut 

 should be driven well into the wood so that the living bark will not be 



Fig. 23. Fi & 24 - 



Fig. 23. A longitudinal cut through the limb shown in Fig. 22e. 

 Fig. 24. The same as Fig. 22e, with the additional feature of a copper wire screen, 

 which gives further protection against rot fungus. (Original.) 



in danger of being peeled off during the operation of removing the 

 rotted wood. Chisels are then used to cut out the rotted wood, which 

 should be removed completely or until the sound, white wood of the 

 interior of the limb is exposed. Frequently, the rotted wood in the 

 limb will be found to extend considerably below and above the limits 

 of the living bark about the dead stub. In such cases it is necessary to 

 make a long, narrow cut of sufficient length to remove this rotted wood. 

 Sometimes the final limits of the rot may be removed with an auger. 



After the cavity has been cleaned the Bordeaux paste is applied to 

 the walls and the cement filling put in place. The edges of the cut are 

 now smoothed with a sharp knife and the asphaltum wax applied. The 

 cement should be allowed to set a little before this last operation. 



