WESTERN DISTRICT. 
285 
Most soils, if not all, yield soluble silica when thus acted upon by water. Sometimes it 
is inappreciable ; at others, susceptible of an accurate determination. This substance, 
without doubt, is one of the essential elements of good grass or pasture land. All the 
cereals require silica, as much as they do carbon : hence, where there is a deficiency of 
soluble silica, we can not hope to obtain good crops of hay or grain. I omit here all 
details, except the common statement in regard to silex, reserving a more special notice 
of this substance for a future section. 
The Marcellus shales, when subjected to the solvent power of water, furnish considerable 
soluble matter. Thus, 200 grains, treated as above, gave 
Soluble matter. 1*98 grs. 
Organic mattter__ 0*63 
Saline matter_ 1 - 35 
The latter was composed of 
Silex_ 0*03 
Alumina or phosphate of alumina tinged with iron, 0-25 
Chlorides of lime and magnesia_ 0-23 
Sulphate of lime_ 0*12 
Carbonate of lime_ 0*73 
1-35 
A specimen of soil from the cornfield referred to above, treated in the usual method of 
analysis, gave 
Water of absorption_ 4’15 
Organic matter_ 5*06 
Silex_80*15 
Carbonate of lime_ 3*00 
Magnesia. 0*50 
Peroxide of iron and alumina_ 7*00 
99*86 
A specimen of soil which has never been cultivated, taken from the same geological 
position as the above, gave 
Water of absorption_ 5 *20 
Organic matter_ 6*50 
Silicates_,_89*05 
Peroxide of iron and alumina. 7 *64 
Carbonate of lime_ 2*05 
Magnesia. 0*25 
104*69 
