THE CHEMISTRY OF SOILS AND MANURES. 
THE CHEMISTEY OF SOILS AND MANTJEES. 
By Dr. A. YOELCKER, Professor op Chemistry in the Royal Agricultural College, Cirencester. 
ON TILE CLASSIFICATION OF SOTXS. 
We resume the description of the different classes of soils : — 
IV. Vegetable moulds (Humus soils). — Any soil containing more than five per cent, of organic 
matter, "whatever else its composition may be, is called a vegetable mould. Soils of the most opposite 
physical characters and capabilities are thus grouped together in the class of vegetable moulds. These 
soils are clayey, loamy, or sandy, according to the predominant character of the earthy admixtures. 
Many are highly fertile, and these are just such as contain, in addition to the vegetable remains, all 
the mineral substances -which plants require for their healthy growth, in sufficient quantities and in 
such combinations, that they are easily available as food to plants. Other soils belonging to the vege- 
table moulds are more or less sterile, but capable of improvement, and some contain so large a prepon- 
derance of organic matters, that they are called peaty, or boggy soils. The relative composition of fer- 
tile and sterile vegetable moulds, and of peaty soils, will become apparent by a glance at the following 
analyses (Nos. I., II., Mulder ; Nos. III. to VI., Sprengel) : — 
No. I. 
No. II. 
No. III. 
No. IV. 
No. V. 
No. VI. 
Organic matter and combined water (humus) . 
12.000 
12.502 
10.90 
16.70 
37.00 
90.44 
Potash .... 
1.026 
1.430 
} .01 
J .06 
trace. 
.01 
Soda .... 
1.972 
2.069 
do. 
trace. 
Ammonia 
.060 
.078 

. 

Lime .... 
4.092 
5.096 
1.00 
.13 
.32 
.55 
Magnesia 
.130 
.140 
.20 
.03 
.31 
.08 
Peroxide of Iron 
9.039 
10.305 
j 6.30 
j .64 
J ,2 
I ■» 
Protoxide of Iron . 
.350 
.563 
Protoxide of Manganese 
.288 
.354 

Alumina 
1.364 
2.476 
9.30 
.78 
.45 
.63 
Phosphoric Acid 
.466 
.324 
.13 
.11 
trace. 
.02 
Sulphuric Acid 
.896 
1.104 
.17 
.02 
do. 
.19 
Carbonic Acid 
6.085 
6.940 




Chlorine . . 
1.240 
1.382 
trace. 
.01 
trace. 
trace. 
Soluble Silica 
Insoluble Silicates (clay) 
2.340 
57.646 
2.496 
51.706 
J 71.80 
j 81.50 
J 61.57 
J 7.96 
Loss .... 
1.006 
.935 
.19 
.02 
100.000 
100.000 
100.00 
100.00 
100.17 
100.00 
Nos. I. and II. Fertile soils of a tract of land in North Holland (between Nieumesluis and Aertswoude), gained by embankment 
from the sea. 
No. III. Rich vegetable mould, near Hoya on the Weser, in Germany, flooded by the river. 
No. IV. Poor sandy mould, near Brunswick. 
No. V. "Very infertile peaty soil, near Aurich, in East Friesland. 
No. VI. Boggy, very sterile land, near Giffliorn, in Germany. 
V. Marly Soils. — Marly soils resemble more or less in their characters calcareous, or clay soils. 
They are always less retentive, less impervious than clay soils, but generally not so open and porous as 
many calcareous soils. On the whole, marly soils belong- to the better, more productive, and more 
generous soils. In marly soils the proportion of lime is more than five per cent., but does not exceed 
twenty per cent, of the whole weight of the dry soil. Any marly soil in which a large proportion of 
clay is replaced by silicious sand, is called a sandy marl Clay marl, on the contrary, is a marl in 
which clay preponderates. 
ANALYSIS OF A MARLY SOIL FROM THE NEIGHBOURHOOD OF CIRENCESTER. (DR. A. YOELCKER.) 
Organic matter and water of combination ...... 10.50 
Oxide of Iron and Alumina ........ 11.92 
Carbonate of Lime ......... 19.92 
Carbonate of Magnesia ......... .25 
Potash ........... .63 
So <*a ........... .09 
Phosphoric Acid . . . , . . . . . . .33 
Sulphuric Acid .......... .0-4 
Finely divided Silica (soluble in caustic potash) ...... 13.45 
Insoluble Silicates and sand (clay) ....... 42.07 
Loss ......... .75 
100.00 
VI. Loamy Soils. — The term loam is reserved to all soils which contain the four chief constituents 
soils, silicious sand, clay, lime, and vegetable and animal remains in a fine state of division and 
intimate mixture, and in such relative proportions that the quantity of lime does not exceed five per 
