CULTURAL CHEMISTRY. 
251 
certain portions of the green-sand formation are notable examples. Of the origin 
of Phosphorus, at present viewed as an elemental base, more will be said. 
The alkalies, Potassa and Soda, are discovered in soils ; not, however, in 
their pure state, and hence their presence was not formerly appreciated ; but as the 
bases of neutral salts in the form of silicates, muriates, or sulphates : all these and 
a small quantity of manganese, constitute what are now deemed the in-organic, 
mineral constituents of vegetable bodies, attracted and taken up by the vital 
absorbent action of their roots, from the soil. 
To enable the reader to estimate the results of a modern process of analysis, 
the following tables are given from the new edition of Mr. Stephen's " Book of the 
," the first part of which was brought out late 
in October 
Soil 
Subsoil 
Subsoil 
S iu-face 
15 in. deep 30 in. deep 
Organic Matter and Water combined 
. 8-324 
7-700 
9-348 
3-911 
3-428 
Crenic acid ..... 
0-731 
0 037 
0-160 
0 152 
1-430 
1-521 
2-069 
1-937 
0-078 
0-075 
5-096 
2-480 
0-140 
0-128 
10-305 
11-864 
Protoxide of Iron ...... 
. 0-350 
0<563 
0200 
0-354 
0-284 
2-576 
2-410 
0-324 
0-478 
Sulphuric acid ....... 
. 0-896 
1-104 
0-576 
6-940 
4-775 
1-382 
1-418 
Soluble Silica ...... 
2-496 
2-286 
. 57-646 
51-706 
55-372 
0-935 
1-231 
100-000 
10-0000 
100 000 
The first four are decomposable organic substances. The alkalies and acids 
exist in combination, but are here exhibited separately, as detached and severed by 
the analytic processes. The ammonia must be adventitious, brought down by rain, 
or extricated within the soil by chemical disturbance among the Organic elements. 
The deduction we must arrive at by a comparison of the elements given in the 
foregoing tables with the products of combustion, is this : — Plants contain certain 
substances, which are deposited in their ashes ; they are saline and earthy ingredients 
that by no reasonable probability could be derived from the air. The analysis of a 
soil yields corresponding substances ; therefore, to the soil we must refer as their 
origin ; and upon this fact depends the theory of appropriate manuring. But till 
science shall have arrived at a point which shall clearly determine the balance of 
supply and demand, our knowledge of the inorganic constituents in soils, and of the 
