The Lois Weedon Plan of Growing Wheat, 609 



tained at about 70°. Even now none of the soils had gained 

 quite 5 per cent, of water ; and as it was thought that the absorp- 

 tion of ammonia would be facilitated thereby, 5 per cent, was 

 now added to each of them ; and after another four days' expo- 

 sure to the moist ammoniacal atmosphere, a further 10 per cent, 

 of water was added. In four days more the little basins were 

 removed from the ammoniacal atmosphere, and by this time the 

 soils smelt very strongly of ammonia. In order to expel all 

 that was not retained in a comparatively stable condition, the 

 little basins and their contents, uncovered, Avere exposed for 

 eighteen hours in the warm room at about 70° ; by which, as will 

 foe seen in the Table, the amount of moisture was reduced in 

 all cases to below 3, and in some to below 2 per cent. In this 

 state the percentage of nitrogen was again determined in the 

 soils by the soda-lime and platinum-salt process ; and in the 

 Tal)le are given the results of these determinations ; and by their 

 side, the mean percentage of nitrogen in the respective soils 

 before they were submitted to the ammoniacal vapours. The 

 percentages of water in the specimens at the different stages, as 

 above described, and the percentage gain of nitrogen by absorp- 

 tion, calculated both upon the dry soils and upon the previously 

 existing nitrogen in them, are also given ; the former to the left, 

 and the latter to the right of the nitrogen determinations, 



A glance at the Table shows that there is some general though 

 not numerically exact connexion between the capacity of the 

 different soils for the al)sorption and retention of water on the 

 one hand, and of ammonia on the other. It is seen that the Lois 

 Weedon heavy land and its subsoil absorbed and retained a very 

 much larger proportion both of water and ammonia than either 

 the Rothamsted soil, or tlie Lois Weedon light land, or light- 

 land subsoil. Thus the nitrogen in tlie Lois Weedon heavy 

 land, which was before the highest in the series, has been raised 

 by the absorption experiment by 0'1925 per cent. ; whilst that in 

 the Rothamsted soil is raised by only 0*1306. The Lois Weedon 

 light land has, however, absorbed, or at least retained, less df 

 ammonia than the Rothamsted soil, the increased amount of 

 nitrogen in its case being 0*0988 per cent. It is further seen 

 that both of the Lois Weedon subsoils have absorbed more than 

 their corresj)r)nding surface soils ; the increased ])ercentage of 

 nitrogen l)y aljsorption of ammonia being in the heavy-land sub- 

 soil 0"2292, and in the light-land subsoil 0"1109 per cent. 



It was our intention, had time permitted, to have completed 

 other experim(>nts of this kind for the purposes of this j)aper ; 

 and we may possibly yet be able before concluding to append 

 the results ot some sucli which arc now in j)rogress. In defect 

 of these, iiowcver, we cannot fail to observe as a significant fact, 



