316 LOOSENING THE SOIL. 



tree is stifled or hidebound, and that this old bark 

 aflbrds shelter for myriads of insects, which ravage 

 the crops the next summer. To restore the tree, 

 the remedy must be applied to the primary cause, 

 in the form of manure to increase the fertility of 

 the land, or by draining to regulate its moisture. 

 The tree should then be scraped so that the moss 

 and old bark shall be entirely removed ; but the 

 instrument used for this purpose must not be too 

 sharp, else it ^Yill mutilate the tree by exposing 

 unduly the liber, or live bark. It is very well to 

 wash the trunk with a very weak dilution of potash- 

 water, to destroy the larvae which may be present. 

 A great many orchards are treated so severely in 

 removing the old bark as really to wound the tree, 

 and the operation is generally rendered fruitless by 

 the scrapings being left upon the ground, in which 

 case the larvae can crawl upon and attack the trees 

 almost as well as if they had never been touched. 

 The bark which is scraped off should always be 

 gathered up and burned, when the destruction of 

 the insects will be certain. 



Loosening the soil. The consta,nt pulverization 

 of the surface-soil, particularly by the use of the 

 hoe, greatly promotes its fertility. By this means 

 it is kept porous, and in a condition to absorb ferti- 

 lizing gases, as well as moisture, from the atmos- 

 phere. It will readily be seen that deep ploughing 

 or spading is injurious. The little fibres which 



