26 PRACTICAL TREE REPAIR 



the sake of appearances, as people are, will do 

 more good than the inventor of an improved 

 preparation. 



Any discussion of dressings for wounds must 

 be prefaced by a determination of the things the 

 dressing is to be called on to do and of the in- 

 fluences which tend to prevent the proper dis- 

 charge of its functions. 



The dressing is put on the wound in order to 

 prevent weather, insects, and fungi from getting 

 at the exposed wood. The weather does but little 

 harm per se, but it is the invariable advance agent 

 of fungi. To be good, a dressing must cover the 

 wound completely, bridging such small cracks as 

 there may be in it, must take tenacious hold on 

 the wood, weather well, and not crack or separate 

 from the wood. It must, in addition, be fairly 

 easy to apply, and must if possible be cheap. 



That it is hard to find a satisfactory dressing is 

 largely due to the kind of surface to which it is 

 applied. Because the surface to which it is ap- 

 plied is usually moist it is hard to make the dress- 

 ing adhere, and because the surface is sure to check 

 it is hard to get a permanent covering. Painting 

 a wound in a tree is absolutely unlike painting a 

 piece of seasoned timber. It is sometimes sug- 

 gested that the dressing ought to prevent evapora- 

 tion and the checking of the wood, but in practice 

 it has been found that no dressing will prevent the 



