the paste is to keep in the steam and with it the aroma of the stew. If properly done, the potatos become throughout impregnated with the aroma of the onions and of the meat, and are unequalled in flavour by any other form of cookery. When the whole is cooked, take up the slab of paste carefully and place it upside down on a hot dish, and tumble out carefully the stew over it. There should be just a little gravy, but never a lot of gravy as if it were a soup. The paste, if well made, becomes also impregnated with the aroma of the stew, and is very nice and juicy if it is not made too thick. Such is a real Irish stew. Practically it is a potato stew cooked by steam. In the English mode of making an Irish stew the whole aroma escapes with the steam and is lost. There are not many that can make a real Irish stew, unless they have been taught by Irish people.

In conclusion, I would remark that it is no more possible to make a good cook by giving him or her recipes on paper than it is possible to make a good pianist by giving him or her a piece of music on paper. Practice and intelligence-and shall I say an appreciative diner ?-are essential to the evolution of a good cook.

HORTICULTURAL SOILS.

By Mr. J. J. WILLIS.

[Read March 22, 1898.]

THE question of soils must always be an important subject to horticulturists, for the reason that if a plant is to grow up strongly and freely, it must have not only good and abundant food, but a suitable and healthy abode. Science, as well as practice, have demonstrated the fact that some kinds of soil are more suitable than others to certain plants, and it is found that the value of different soils for horticultural purposes is greatly dependent upon the original material from which they were made, and upon the state of fineness to which they have been reduced.

FORMATION OF SOILS.

All soils have been formed by the disintegration of rocks, through the prolonged action of water, air, and frost; and in

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the latter stages of their history by the action of vegetable and animal life, and their products. When once a soil has been brought under cultivation, the continual ploughing, digging, hoeing, stirring, and other operations of the gardener-all comprehended under the term " tillage "-assist most powerfully the weathering influences, and cause cultivated soils to become finer and more permeable, and consequently in that respect better and better.

The purposes of tillage are twofold. First, it improves the texture of the soil in the mere mechanical sense; or, in other words, it stirs and loosens the soil so that the roots of plants may readily pass through it. Air and water are allowed to enter freely, and water is enabled to pass easily through the mass, while at the same time it ensures that the soil shall retain a sufficient amount of moisture for plant-life.

Secondly, tillage alters the position and condition of the soil particles, facilitating the chemical changes in these particles through the action of atmospheric agencies. Helping also the microscopic organisms in their work of nitrifying the organic matters contained in the soil.

The weight of soil on an acre of land is so enormous that small proportions of plant-food present in it may amount to very considerable quantities when reckoned up to the acre at any given depth. Table I. illustrates the weight of different descriptions of soil, cut to 9 inches deep, when perfectly dry and free from stones.

TABLE I.—WEIGHT of an ACRE of SOIL, cut to 9 inches deep, Dry and Free from Stones.

These illustrations show that an acre of sandy soil will weigh 3,500,000 lbs.; an ordinary arable loamy soil 3,000,000 lbs. ; a pasture soil when dried and the visible roots removed will weigh about 2,250,000 lbs.; a forest soil that contains an abundance of decaying vegetable matter will weigh but 1,500,000 lbs. per acre; while an acre of peaty soil cut to 9 inches deep, in consequence of its light and spongy character,

will weigh only 1,000,000 lbs., or in some cases possibly even less.

THE USES OF SOIL.

The uses of a soil to plants are to provide a firm yet sufficiently deep and porous layer, into which the roots can penetrate, and extend their fibrils and rootlets in every direction. The soil has to support the plant in an upright position, and keep it firm, when in the open air, against the storms of wind and rain. It must allow of the free percolation of both water and air, which are so necessary to the life and growth of the plant, and to the due preparation of plant-food in the soil. It must retain sufficient moisture to furnish the growing crop with an immediate supply of water, and its pores must be sufficiently fine to allow of the ascent of water from the subsoil by capillary attraction. It must store up some of the heat received from the sun in the day-time, and so render the temperature of the soil more equable. It also serves as a protective covering to roots and seeds against excessive summer heat and winter frosts.

A soil should contain in itself a stock of the mineral food necessary to the growth of crops, and it must constitute the laboratory of a number of wonderful actions whereby plantfood is always being prepared little by little for reception and assimilation into the plant. For a soil to be fertile it must permit of the various tillage operations by which alone the surface can be kept free from weeds, and given the proper conditions of texture necessary for the sowing of different seeds, and for the healthy development of the various crops grown upon it.

All fertile soils are made up more or less of each of the following substances:-Gravel, clay, sand, carbonate of lime (chalk), and vegetable matter. Each of these ingredients can be discovered in, and separated from, a soil by simple means. The proportions in which they are mixed together in any given soil have great influence on the uses to which the soil can be put in practical horticulture, and the kind of crops and individual plants best fitted for it to grow.

Table II. gives an illustration of the mechanical analysis of five different descriptions of soil, cut to 9 inches deep. The quantities are quoted in 100 lbs. of each, free from moisture:

TABLE II.--MECHANICAL ANALYSIS of DIFFERENT DESCRIPTIONS of SOIL, cut to 9 inches deep.

The quantity of gravel is seen to range from less than per cent. to over 9 per cent. The sand ranges from 28 to 72 per cent. The clay, including lime and soluble silica, ranges from 2 per cent. in the Ghent heath mould to about 52 per cent. in the rich pasture soil. The organic matter ranges from about 7 per cent. to 64 per cent. The Ghent heath mould is composed of more than five-eighths of its total weight of organic matter. It may, therefore, be easily understood that the ready-formed plant-food in soils, whether of mineral constituents or of nitrogen, is a very fluctuating quantity, often falling below the needs of a particular crop, as regards one or other ingredient. It is only the very rich virgin soils, formed by breaking up of natural pastures of newly settled countries, or such soils as the Ghent heath mould, as quoted in Tables II. and III., that are practically inexhaustible.

THE SOIL AS A SOURCE OF PLANT FOOD.

In order to start with definite notions about the inherent fertility of soils, I may state that where any plant, however lowly, has once grown and died away, its remains gradually decay and add a little vegetable or organic matter to the soil, rendering it thereby capable of growing a better plant the next season. As the soil becomes richer in carbonaceous and vegetable matters, higher organised plants will occupy it; these pass through the same phases of life as the plants of simpler structure, and enrich the soil at an increasing rate by the expanded flora, as well as by the greater bulk of their products

that fall victims to organic law. We have to remember, further, that the greater part of the weight of every plant is obtained from the air, and only a very little is derived from the soil. Not only so, but it is a fact, and a very important one, that new plants grow much more quickly than the remains of the old ones decay and disappear; hence organic carbonaceous matter must always be increasing in a soil left in a state of nature and uncultivated.

The character and amount of plant-growth is found to differ considerably in different soils, and the largest quantity of produce will be grown on the soils where the wild plants could get the greatest amount of food. It happens, therefore, that the virgin soils, as they are termed, derived from the heath, the forest, or the prairie, which are first ploughed up by the settlers in new countries, are richly charged with a blackish-brown vegetable substance, known under the general name of humus, and recognised as one of the marks of a fertile soil. In fact, humus was considered by agricultural chemists in the early part of the present century to be the main source of soil fertility.

But without supposing that plants feed directly upon humic matter, it is easy to see why the proportion of this substance is often a very fair measure of the productiveness of a soil, for the reason that it represents the material accumulated by a previous succession of crops.

Table III. shows the proportion of organic matter, and of nitrogen in the organic matter, in seven descriptions of soil, in quantities per acre, the soil being cut to 9 inches deep.

TABLE III.-ORGANIC MATTER and NITROGEN in DIFFERENT DESCRIPTIONS of Soi per acre, cut to 9 inches deep.

The figures show a very considerable range in the amount of