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it brings forth sickly watery branches, because it 

 cannot give them their duly-prepared supply of food. 

 The point to he gained, then, is to secure the con- 

 version of gum into some more dry and solid form of 

 matter. This is the more important in a peach tree, 

 because that plant, like all stone-fruit trees, naturally 

 produces gum in excess, and it wants the power 

 which many plants possess of rapidly converting it 

 into something else. How is this to be done ? Gum 

 is converted into starch or wood by the loss of a por- 

 tion of the water in combination with it. A loss of 

 one part of water in eleven produces starch, and of 

 three parts in eleven produces wood. A separation of 

 the water of combination is produced by heat and 

 light, and by no other known agents. In proportion 

 as the branches are heated and exposed to bright 

 light are starch and wood formed at the expense of 

 gum ; we may also conceive that, in a similar propor- 

 tion, unchanged gum is dried off by the evaporation 

 of its water of solution, and vice versa* Now, one of 

 the first means to effect this end is to take care that 

 no more wood is produced than can be fully exposed 

 to sunlight ; and that all such wood is continually 

 nailed close to a wall, whenever it is long enough to 

 be so secured ; in order that the reflected heat of the 

 wall may be absorbed by the branches. All the sys- 

 tems of leaving fore-right shoots, or of putting off 

 summer pruning till the winter, and tucking in the 



