234 



IRRIGATION. 



Geine, 



Silex, 



Oxide of iron, 



Alumina, 



Lime, . 



Magnesia, 



But considering the elements as we have usually treated 

 them as silicates, salts and geine, the composition of the sev 

 eral deposits is shown in the following table ; 



3.92 

 72.70 

 9.15 

 8.30 

 0.51 

 0.10 



Geine. 



Soluble. 



Insol. 



Sulphate 

 of lime. 



Phos. of 

 lime. 



Silicates. < 



5. 



.06 

 5.40 



1.86 

 6.50 

 6.30 



0.74 

 2.34 

 3.20 



0.90 

 1.20 

 0.60 



94.44 



84.66 

 81.20 



The coarse de- 

 posit above. 



Freshet, 1839, 



Freshet, July 

 7-18, '39, 



285. If the doctrine of the action of silicates, salts and 

 geine, upon each other, when aided by growing plants, is con- 

 sidered, it cannot fail to be perceived, that the fertility of 

 soils, periodically oversowed by turbid waters, is owing to 

 the elements, salts and geine, which it contains, and to the 

 exquisitely finely divided state of the silicates which form 

 the bulk of the deposit. The carbonic acid of the air acts 

 on each atom of silicate, while owing "to the geine having 

 been, as it were, irrigated, the oxygen of the air and water 

 must put that into a state to evolve carbonic acid. Hence, the 

 silicates are at once decomposed, and their alkali liberated. 

 How beautiful ! It seems like a special interposition of that 

 beneficent Power, whose blessings, while they fill us with 

 wondering admiration, at the infinite skill which directs 

 every change in the material universe, should teach us also, 

 that these changes are held up to us, not only to admire, 



