SPRINGS OFTEN e'nRICH THE SOILS. 285 



"elde, in Osnabruck, which gives excellent crops, though manured only 



Mice in 10 or 12 years. 



Silica and coarse Quartz Sand .... 86*200 



Alumina 2-000 



Oxides of Iron and a little Phosphoric Acid . 2*900 



Oxide of Manganese 0*100 



Carbonate and a little Phosphate of Lime . 4*160 



Carbonate of Magnesia 0*520 



Potash and Soda 0*035 



Phosphoric Acid 0*020 



Sulphuric Acid 0*021 



Chlorine '...'.. 0*010 



Humic Acid 0*544 



Insoluble Humus 3*370 



Organic matter containing Nitrogen . . . 0*120 



100 



You will see that, although in this soil all the inorganic substances are 

 really present, yet the potash and soda, the phosphoric and sulphuric 

 acids, and the chlorine, are not in such abundance as to justify us in ex- 

 pecting it to grow any long succession of crops, without exhibiting the 

 usual evidences of exhaustion. But it lies on the side of a hill which con- 

 tains layers of lime-stone and marl, through which the surface waters 

 find their way. These waters afterwards rise into the soil of the field, 

 impregnated with those various substances of which the soil is in want, 

 and thus, by a natural manuring, keep up a constant supply for each suc- 

 ceeding crop. 



This example is deserving of your particular attention, inasmuch as 

 there are many soils, in climates such as ours, which are yearly refresh- 

 ed from a similar source. Few spring waters rise to the surface which 

 are not fitted to impart to the soil some valuable ingredient, and which, if 

 employed for the purposes of irrigation, would not materially benefit 

 those lands especially on which our pasture grasses grow. The same 

 may also be said of the waters which are carried off in some places so 

 copiously by drains. Whether these waters rise from beneath in springs, 

 or, falling in rain, afterwards sink through the soil, they in either case 

 carry into the brooks and rivers much soluble matter, which the plants 

 would gladly extract from them. On sloping grounds it would be a 

 ])raiseworthy economy to arrest these waters, and, before they escape, 

 to employ them in irrigation. 



The fact that nature thus on many spots brings up from beneath, or 

 down from the higher grounds, continual accessions of new soluble mat- 

 ter to the soil, will serve to explain many apparent anomalies, and to ac- 

 count for the continued presence of certain substances in small quantity, 

 although year by year portions of them are carried ofT the land in the 

 crops that are reaped, while no return is made in the shape of artificial 

 manure. It will also in some instances account for the fact that, after a 

 hard cropping, prolonged until the soil has become exhausted, a few 

 years' rest will completely re-invigorate it, and render it fit to yield 



