No. 144.] 251 



One theory of the saltness of the sea, attributes it to the influx 

 of saline materials from the rivers, and continual concentration 

 by evaporation. It is said that all lakes that have no outlet are 

 salt. If this idea is correct, and if three-fourths of the water that 

 falls on a continent never reaches the ocean, but after soaking 

 through the soil in various conditions, finds its way to the surface, 

 and is evaporated again, leaving its inorganic salts, then the full 

 power of this force will be seen, and I shall be justified in enu- 

 merating the rivers as one of the compensating influences. 



If a wagon load of sand be thrown upon a portion of dry ground 

 and left there for a day or two, on removing it, the ground will 

 be found moist under it. It is well known that a field in good 

 tilth suffers less from drouth, and that the best practical remedy 

 for lack of rain, is in deep culture. There is a kind of soakage 

 thus continually going on from below upward in loose soils. 

 That loosening of the soil that favors ihis is in northern climates 

 effected by the winter frosts. Water expands in freezing one- 

 ninth, and consequently for every nine inches that the frost ex- 

 tends, the surface of the earth is heaved up one inch, and uni- 

 formly rendered porous. This favors upward transudation, and 

 is perhaps one reason why northern soils " come in" again better 

 than southern ones, by the lapse of time. It seems to have been 

 granted to them in consideration of a deficiency of solar influen- 

 ces. V7hen we reflect that every grain of the ashes of plants was 

 once dissolved in water and presented in that condition to the 

 roots — that the vital forces of the plant could have had no influ- 

 ence in effecting that solution, these considerations are seen to be 

 of much importance. Experiments made within a }ear seem to 

 indicate that it is good practice to turn water enough upon 

 meadows to thoroughly wet them for the jturpose of effecting this 

 kind of subsoil culture by frost. 



Of that portion of water that does eventually reach the sea, 

 much might be retained by arrangements fir irrigation. Those 

 rills that run directly down the hills might be taken out along 

 their sides in water furrows, with a descent of the half of one 

 degree. I have h<id occasion to prove that meadows dressed in 

 this way are vastly benefited, and some facts seem to indicate 



