24 TREE WOUNDS AND DISEASES 



the interior surface rendered sterile by an 

 application of carbolineum or kerosene. For 

 wound dressings gas-tar and liquid asphalt are 

 also to be recommended, this combination 

 forming a more continuous and elastic covering 

 than is the case when tar or paint alone is used. 

 Where the cavity is small and, as is often 

 the case, filled with water and decayed and 

 decaying vegetable matter, the following course 

 is recommended. When only a few inches 

 deep, the water can usually be got rid of by 

 mopping it out with a sponge attached to a 

 convenient handle ; but when the hole is too 

 deep for this method the water may be got 

 rid of by tapping, that is, by boring a hole 

 with an auger through the trunk to the 

 bottom of the hole. A half-inch auger will 

 suffice, and the correct spot to bore can usually 

 be ascertained by measuring the depth of the 

 hole. After the water has been removed the 

 cavity must be thoroughly cleared of all decay- 

 ing tissue and accumulated vegetable matter, 

 and in order to do so effectually it may some- 

 times be necessary to enlarge the opening so 

 that a suitable tool may be inserted. 



