Tin: Mdismci: i\ Tin: soil 4'.i 



()7. llvi^ro-sc-opic water is that wliioh is held 

 firmly as a liliii surrouiKliii^ each particle of 

 soil. It dtx's not movo nndiM- tlio inlluence of 

 gravity <>r «'ai»illarity, and it is held so firmly 

 that it is driven o(T only when the soil is 

 exposed to a temperatnn^ of '2V2^ Fahr. Thr 

 dryest road-diist liriiily ln>Ids its liyi::ros('()pi(' 

 watt-r, and it may constitute from - to ;; jicr 

 cent (jr more of the weight of the soil. If u\ 

 service to plants in any way, it is only dur- 

 ing the most excessive droughts, in which case 

 it may sustain the plants for a time, until 

 ea]>illai-v wat«M' is sui>]ilie(l. 



ti*^. liolli rapillary and hygroscopic wati-r arc 

 frecjuently n-ferred to as "film moisture," froni 

 the fact that they are hehl as a lilm of greater 

 or l.'ss thickness around the soil parti(des. 

 That part which has the most intimat«' and 

 p 'rmancnt contact with the j)arti«de is the hygro- 

 scoj.ic water, and the outer part of the lilm, 

 whi<'h may move away from the soil ])arti«'le, is 

 the capillary water. N <'ry wet land is that 

 which contains to(» much free water ; whereas, 

 soils which are dryish and cnnnMy usually 

 contain sufficient water for tli<' growing ot 

 plants. That is, lands in good <'«)ndition foi 

 tiie growing of crops are moist, not wet; an«l 

 wo may, therefore, speak of the moi.sture ol the 

 > >il rather than the water of the roil 



