vegetate in excessive moisture. The standing of rain or snow water upon the surface, is also evidence of a superabundance of moisture, or if, afterward, rents or cracks appear, or a crust of ice form in the furrows at the slightest frost. Finally, the appearance of the soil at certain seasons, shows that it suffers on account of too much water. If, for example, the spring winds have dried the surface of the ground, so that one would think all the moisture gone, and dark spots present themselves upon the surface, this shows that much water stands there.

We will now proceed to give a chapter on soils generally, and their properties, then to state how drainage operates, and also discuss the advantages of underdraining by demonstrating-so far as theory (not hypothesis), in its proper sense, is susceptible of demonstration—that drainage,

I. Removes stagnant waters from the surface.

II. Removes surplus water from under the surface.
III. Lengthens the seasons.

IV. Deepens the soil.

V. Warms the under soil.

VI. Equalizes the temperature of the soil during the season of growth.

VII. Carries down soluble substances to the roots of

plants.

VIII. Prevents "freezing out," or "heaving out."
IX. Prevents injury from drought.

X. Improves the quality and quantity of the crops.
XI. Increases the effect of manures.

XII. Prevents rust in wheat and rot in potatoes.

CHAPTER I.

PROPERTIES OF SOILS.

IN a work of this character, it may not be necessary to describe the chemical composition of soils, although very proper to state what properties are desirable for remunerative cultivation. It not unfrequently happens, that the properties or qualities of soil are inherent: that is, the cause of productiveness is to be ascribed to the peculiar combination of substances composing the soil, which no chemical analyses have yet been able to discover, and which has not been produced by any artificial combination or process. Scientific investigations of the soil have accomplished little else than a determination of the elementary substances or constituents, as well as some inherent properties, such as color, weight, and facility of combination with other ingredients. A practical examination of the adaptation of soil for cultivation, renders a consideration of some of the other properties necessary.

The physical properties of the soil are of very great importance, so far as the culture of plants is concerned. It may, perhaps, not be asserting too much to say, that the physical properties of the soil exert a more direct influence upon the plant, upon the atmosphere in contact with it, and upon water, than do the chemical combinations of its elements. The degree of fineness of the mineral particles of the soil; its power of cohesion, moisture; its adaptation to the percolation of water, and permeation of atmosphere; its power to absorb moisture by capillary attraction, to absorb gases, to retain heat or warmth, exert, perhaps, a greater influence than is generally believed.

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Therefore, it is, why soils frequently are nearly identical in their chemical analyses, yet differ so materially in their productiveness. Underdraining proposes simply to affect the physical condition of the soil without disturbing its chemical composition.

Clay-Pure clay forms a very heavy and compact soil; but if it is burned and then ground, it forms a very porous soil, and is much better adapted to the growth of crops. A soil in which silicious (flinty sand), and calcareous (limey) earths predominate, becomes so hot and parched, that the plants wither and die; on the other hand, if these same substances are finely comminuted or reduced to powder, they form a soil which absorbs entirely too much moisture, and plants suffer in consequence.

One hundred pounds of calcareous earths in an ordinary state, will absorb twenty-nine pounds of water, but when finely comminuted, will absorb eighty-five pounds.' Silicious earths, which usually retain no more than twentyfive per cent. of moisture, when properly prepared in a chemical laboratory, may be made to retain two hundred and eighty per cent. of moisture.

The variety of colors in soil, is not very considerable, generally brown or gray, changing into yellow; but sometimes it is found very red or black; sometimes it is strongly inclined to white, blue or green, and sometimes. almost endless shades present themselves. The soils all appear much darker in the field than in the laboratory, because in the former place they are always moist, and in the latter, dry. The predominating mineral constituent, generally, imparts the color to the soil-thus, a soil in which iron predominates, is of a reddish hue, an alumin

1 Gerardin's Views of Agriculture.

ous one, yellow, a calcareous one, bluish or whitish. When humus (decayed vegetable or organic matter) is mingled with a soil, it assumes a dark brown or blackish appearance, so that, in course of time, the original color of the soil will entirely disappear. Porphyry, mica schist, the clay slates, and the various sandstone formations produce a reddish soil. Basalt produces a brown or black; serpentine, green; phonolite or clinkstone (a feldspathic rock), white; sandstone, plaster and white lime produce a whitish gray soil. Humus (when derived from turf alone) produces at first a grayish brown, but eventually a black soil. Luster occurs in connection with color, only in instances where a moist clay has been overturned by a polished plow or other smooth metallic substance. When such polished surfaces occur on the soil, as it is being plowed, they are unmistakable evidence of comparative nonproductiveness, because they indicate a want of humus and porosity. Soils in which mica, or small shining particles, abound, is generally not of good quality.

The color is of great importance in practical agriculture, from the well-known fact, that dark colors always retain the heat from the sun much longer than light colored ones.

Dark soils are generally acknowledged to be more productive than light ones-but this fertility is due to other causes, perhaps, in as great degree, as to the color-they generally contain humus, or at least some organic matter. If, then, we assume the importance of the color of the soil as a fixed fact, and as a condition having an influence on temperature, we then have some data from which the amelioration or improvement in a physical aspect is to be determined.

Experience has taught that coarse dark particles of soil retain warmth longer than fine particles; hence, intelligent

gardeners often mix muck, fine coal, bonedust, etc., with some calcareous soil, and distribute it among the soil in the hotbeds, and between the grapevines, when they wish to force fruits and fit them early for market. Sometimes they strew bits of slate around the plante-"this is mainly practiced on the banks of the Moselle, Nahe, Maas and the Rhine." On a dark soil the vine always becomes more juicy, and contains more saccharine matter than on light soils in the same situation in all other respects.

Numerous experiments might be cited to prove that the color of the soil varies the temperature nearly fifty per

cent.

For example: if a calcareous clay soil is placed in a white flower pot, and exposed to the rays of the sun, it will increase sixteen degrees only in temperature, while the same soil in a black pot by the side of it, will have increased twenty-four degrees. Gerardin asserts that the period of ripening potatoes is varied from eight to fourteen days, by the color of the soil. In proof of this, he planted, at the same time, an equal number of varieties. in different soils, and found that in white clay sixteen varieties; in yellow clay, nineteen; in whitish sandy soil, twenty, but in dark humus soil, twenty-six varieties, had fully ripened at the same time.

As the density or compactness of soil is differently understood by different parties, we shall endeavor to be as explicit as possible on this point. Generally, by density or heaviness, is understood the amount of pressure which one body exerts on another, or in other words, density and specific gravity are regarded as synonymous. But in agricultural literature, heaviness is rather synonymous with compactness or cohesiveness, than with weight. By a heavy soil, is meant one that is difficult to work, on

1 Yager's Bodenkunde.