504 _A. B. BEauMont 
moisture content than that of the continuously moist and undried soils 
with which they were compared. The comparison between any two 
conditions of the same soil were made in the humidifier at the same time. 
TABLE 11. Errect oF REMOISTENING SOILS ON THEIR ADSORPTION OF WATER VAPOR 
Original Per cent 
Soil waiter Treatment of water Ditference 
content adsorped 
(per cent) 
Dunkirk surface... 10.7 Continuously moist........ 3.8)+0.06 
25.0 Aic-dried and remoistened..| 3.38+0:05 0.42+0.08 
Clyde surface. .... 42.0 Continuously moist........ 18.9 40.2 34 +0.04 
48.7 Air-dried and remoistened. .| 15.8 +0.3 3 ; 
Dunkirk subsoil. . . 17.8 Continuously moist........ 5.77+0.01 0.51-40.02 
18.7 Air-dried and remoistened..| 5.26-0.02 2 4 
Vergennes subsoil. . 18.9 Continuously moist........ 17.60+0.05 0.20-+-0.07 
De Air-dried and remoistened. .| 17.40-++0.05 5 ; 
In every case the remoistened soils contained less hygroscopic moisture 
at the end of a week than did the continuously moist soils, altho the 
remoistened soils held more water at the beginning of the experiment. 
The differences, according to the standard set (footnote, page 492), are” 
significant in all cases except that of the Vergennes soil, in which case the 
chanees are 10 to 1 in favor of the continuously moist soil (Wood and 
Stratton, 1910). 
These data indicate rather clearly that in the case of the air-dried soils 
the hygroscopicity is not immediately restored by remoistening. It may 
be observed that the greatest diuference here is with the soil containing 
the greatest amount of organic matter and humus — the Clyde surface 
soil (table 9, page 502). 
Altho it cannot be definitely stated whether these differences in water- 
vapor adsorption are due to the effect of drying on the colloidal matter 
or to the effect of drying on the adsorbed air, if it be assumed that the 
effect is on the total surface of the soil there is strong evidence of its being 
more or less permanently diminished by air-drying. In other words, the 
change due to drying out is not an immediately reversible one. 
Permanency of the effect of drying.— It was noxt attempted to ascertain 
the permanency. of this effect of air-drying. Some of the same soils used 
