WOOD-ROTS: THE TREATMENT OF TREES 105 



3. If experience of the kind of tree, the vigour of its growth, 

 and the size of the wound indicate the necessity, the wood should 

 be treated with an antiseptic or a protective covering to preserve 

 it until the wound has time to heal over. 



4. If a cavity has formed from an old wound the rotten 

 wood should be dug out, an antiseptic applied, and the cavity 

 filled with cement to the level at which the callus is expected to 

 extend over it. 



It will be found that some species of trees heal wounds very 

 much more readily than others, that young trees heal more 

 quickly than old ones of the same species, and of course that 

 some woods are very much more durable than others when 

 exposed. 



Wounds near the soil level are the worst to deal with, as the 

 soil moisture greatly increases liability to infestation and rotting 

 of the wood. Treatment of wounds about the collar and the 

 crown roots should be accompanied by removal of the soil about 

 them, and also of sheltering weeds or low branches. In humid 

 localities where moss accumulates the bark should be scoured by 

 spraying or swabbing with lime-sulphur or some other detergent. 



The treatment of canker, gummosis, and bark rots generally, 

 consists of cutting back to sound bark, the scraping of the wood, 

 and the application of a preservative to the latter. The practice 

 of gouging out the underlying discoloured wood has to the 

 writer's mind little to commend it. Though fungus hyphse may 

 be present, the drying out of the wood, its impregnation with an 

 antiseptic or the exclusion of air by a protecting coating, which- 

 ever is most appropriate to the particular case, is likely to be 

 quite as effective. 



Antiseptics. 



The antiseptic most in favour at present is o.i per cent, 

 corrosive sublimate solution (see page 99). Its effects are 

 evanescent and are liable to be interfered with by substances 

 present about the wound. Applied to the surface of wounds 

 just previous to the application of a protective paint or filling it 

 may be expected to have a certain amount of usefulness in 

 destroying spores or mycelium already present. There have 

 been grades of carbolineum specially prepared so as not to be 

 injurious to bark, and if a reliable brand could be obtained this 

 material should in many cases be the most satisfactory to use. 

 Bordeaux and Burgundy pastes are to some extent in use as 

 temporary antiseptics. 



The covering of a wound with a good waterproof coating is in 

 itself sufficient to alter the conditions to the disadvantage of 

 some kinds of wood-infesting fungi. 



Protective paints. 



Numerous substances are or have been in use for covering 



