240 
ANALYSES OF SOILS. 
in it. It is quite refractory in the fire, and fuses only after urging the heat of the furnace. 
Its fineness fits it for looking-glass frames, forming a base on which to gild ; besides which, 
it will undoubtedly answer for all the ordinary purposes of potter’s clay. It is now used 
only for brick, the color of which is a pale yellow brown. It is composed of the following 
elements : 
Water of absorption_ 
Water and organic matter_ 
Silex_ 
Peroxide of iron and alumina 
Carbonate of lime_ 
Carbonate of magnesia_ 
Carbonate of potash_ 
Phosphate of lime_ 
Chlorine_ 
Sulphate of lime_ 
_ 2-284 
_ 4-240 
_ 60-160 
__ 7-790 
__ 0-940 
_ 0-600 
_ 0-110 
amount undetermined. 
- trace. 
_ none. 
76-124 
The specific gravity of the Adirondack clay is 2• 1034, which may be taken as a standard 
for stiff clays that are destitute of organic matter. 
Had this clay been derived from an ordinary coarse granite, one whose felspar and mica 
contain potash, it would probably have formed the porcelain clay. Lime is a more stable 
element, less soluble than potash, and hence it has been retained, and remains in combi¬ 
nation with the silex, or perhaps with carbonic acid. It does not effervesce with acids. 
The existence of this clay in the midst of this highland district offers encouragement to 
look for deposits of the same material in all of our other primary or mountainous districts. 
The Southern Highland district, in consequence of its insulated position and its limited 
extent, furnishes but imperfect examples of a primary or granitic soil. On the eastern 
side of the Hudson river, near Peekskill, gneiss and granite prevail. In consequence, 
however, of the proximity of the slates and limestones of the 'laconic system, the great 
mass of soils seem to belong rather to the latter than the former rocks: they possess at 
least a mixed character. We find limited areas where the primary rocks have been de¬ 
composed, and in which particles of mica and felspar abound; but we have not submitted 
the soils occupying such limited areas to analysis. 
The following result of a chemical examination of the soil of Peekskill, resting on 
granite, must suffice for this part of the Highland district: 
Water of absorption_ 2-79 
Organic matter_ 7-65 
Silex_ 75-83 
Peroxide of iron and alumina_ 12-00 
Carbonate of lime_ 1-15 
Magnesia_,_ 0-68 
100-10 
