9a GERMINATION 



Maidstone, much of which was waste land. Its sterility- 

 was due to no fault in the soil, which is obviously of excellent 

 type, but to a thin layer of rock lying near the surface. 

 When this was removed a very good soil was obtained. 

 The Harting soil, on the Upper Greensand, in West Sussex ; 

 the rock comes close to the surface, restricting both the 

 root range of the plant and the water supply where it lies 

 horizontally, but proving much less harmful where it dips 

 at any considerable angle . . . The Dicker soil . . . 

 is far from being hopeless, but it unfortunately hes on a 

 deep bed of stiff clay which keeps it wet in winter and 

 parched in summer, . . . Over-drainage is illustrated 

 by the Shopwyke soil . . . it is spoiled by lying on a 

 deep bed of gravel only nine inches or a foot below the 

 surface. . . . Consequently it dries out badly in summer 

 and does not repay much expenditure in the way of manures." 

 Let us study these problems with a view to seeing how 

 far electrical conditions may enter into them, for if I have, 

 as I claim, discovered a fundamental truth, electricity must, 

 of necessity, be concerned in the matter. First we will 

 have a few brief facts for our guidance : 



(1) Dry soil is non-conductive of electricity. 



(2) Water is mainly required as an electrolyte. 



(3) Other things being equal soil conductivity rises 



and falls with rise and fall of temperature. 



In the case of the pan first mentioned, swamp conditions 

 would, of course, involve drainage, but the effect of such a 

 formation would not only be to modify profoundly the 

 movements of water and air but also that of the earth current. 



Now, while water is essential as an electrolyte it is not 

 an electrolyte of low resistance and it is to be feared that 

 vegetation would fare badly if soil conductivity depended 

 on moisture alone, for current in sufficient quantity is 

 required to be constantly supplied to the roots. 



In much the same way that the path of lightning from 

 cloud to earth is governed by the distribution of electrolytes 

 in the air so the direction or directions taken by earth currents 

 must be subject to the distribution of electrolytes in the soil 



