WESTERN DISTRICT. 
273 
Water of absorption_ 0*56 
Organic matter_ 5*00 
Silex_ 34*56 
Carbonate of lime_ 43*06 
Alumina and protoxide of iron. 13*36 
Sulphate of lime_ 1*06 
Magnesia. 2*17 
99*71 
The red and green marly rock, when submitted to the action of cold water, furnishes 
a quantity of soluble matter. Thus from 100 grains, we obtained of 
RED MARL. GREEN MARL. 
Soluble matter_ 1*25 3*50 
Organic matter or acids_ 0*57 0*87 
Saline or bases_ 0*68 2*63 
The thin beds of green shale are subject to decomposition, and the debris remains on 
the dry shelving rocks in the form of gray bitter powders, consisting mostly of the sul¬ 
phates of soda and magnesia, mixed also in varying proportions with the chlorides of 
sodium, magnesium and calcium, and the sulphate of lime and sometimes alumina. One 
hundred grains of the most earthy powder yielded of 
Soluble matter_ 6*53 
Organic matter_ 1 *03 
Saline matter_ 5*50 
The latter consists of the above enumerated elements. In many instances the saline matter 
may be collected in a pure condition, or nearly free from earthy matter. This fact explains 
the cause of the constant fertility of the soils derived from these rocks : the amount of 
saline matter which they furnish is always sufficient to supply the wants of vegetation. 
The analysis of the shales gave another important fact, namely, that the organic salts 
exist in them ready formed. 
Vegetable materials may be recognized always when they are ignited, both by their 
blackening, and by the peaty odor which they exhale when subjected to the action of 
heat. This organic matter must have been derived from vegetables which belonged to the 
period when the rocks were being deposited. It also increases the fertility of the soil ; and 
as it is furnished in proportion to the disintegration of the rock, it can rarely happen that 
the soil will be exhausted of its organic matter by a judicious course of husbandry. 
The condition of the organic matter is much the same as that which exists in ready 
formed soils : crenic and apocrenic acids constitute the greater part of it. These are 
combined with the alkalies and alkaline earths, which, when they have been ignited, are 
decomposed, and pass to the condition of carbonates. Hence it is that we obtain carbonates 
in all our analyses, where rocks or soils have been subjected to a red heat. The carbonates 
| Agricultural Report.] 35 
