136 EXPERIMENTS WITH PLANTS 



a perfect felt of roots will usually be found next the 

 pot. These should be removed, since they are sure to 

 be injured in any case and their subsequent decay may 

 affect the rest of the root. Remote the outer part of 

 the ball of earth (which has become compact and 

 sour) , hold the plant with the left hand at the proper 

 height in the new pot, and with the right hand pack 

 the fresh earth about the roots. The pot may then be 

 immersed in water until bubbles cease to rise. 



Trees which are intended for transplanting should 

 have the roots confined to a small space by transplant- 

 ing and root -pruning once a year. Trees with spread- 

 ing roots may be treated as follows : Some time before 

 the tree is to be transplanted a trench is dug about it 

 and filled with good earth. From their cut-off ends 

 the roots will send out new rootlets into this earth. 

 When this is accomplished the tree, with its ball of 

 earth, may be pulled over and then raised by a suit- 

 able tackle, and transported. (In addition to these 

 precautions, it is important in transplanting trees to 

 see that the points of the compass remain in the same 

 relation to the tree in its new position, i. e., that the 

 north side shall remain the north side after transplant- 

 ing; for reasons, see page 220.) 



The water contained in the soil dissolves out from 

 it mineral substances (such as the salt, which is con- 

 stantly carried to the sea, and the lime, which is de- 

 posited in boilers, tea-kettles, etc.). Are these mineral 



