THE COMPOSITION OF THE SOIL 



123 



and in addition traces of phosphorus and of ammonia. This 

 soil contained 19-1 per cent, of water. 



The total concentration is seen to be about -08 per cent. 



Gola (108) also adopted the artificial rain device but the 

 addition of water ceased as soon as a regular flow from the 

 soil had set up : the soil was then allowed to drain for some 

 36 hours ; the solution thus obtained was called the " pedolytic " 

 solution. Finally, the water was squeezed out by a screw 

 press ; this was called the " pedopiezic " solution. The total 

 concentration varied in different soils from 2 per cent, down 

 to 0"2 per cent, or less, the lower amounts being from soils 

 corresponding to normal agricultural soils (see p. 237). The 

 weak point in the method is that the added water may upset 

 some of the adsorption relationships of the soil and thus 

 vitiate the results. Itscherekov ^ substituted methyl or ethyl 

 alcohol ; van Suchtelen ^ used paraffin oil ; J. F. Morgan (203) 

 improved on this by using paraffin oil under pressure and 

 obtained a solution containing 0*04 to 0*13 per cent, of total 

 solids. Some of his analyses are given in Table XXXIV. : — 



Table XXXIV. — Composition of Soil Solution (Oil Displacement). 

 J. F. Morgan (203). 



^ Russian J. Expt. Ag., 1907, 8, 147-165, 

 ^y.fiir Landw., 1912, 60, 369, 



