A loamy soil requires less manure to keep it in heart than either clay or sand; for while it is favourable to the process by which organic matter buried deep in the soil is converted into insoluble humus, it also permits that part of it which is nearer to the surface to attract oxygen from the air, and thus it is converted into a soluble extract, which is to the roots of plants what the milk of animals is to their young—a ready-prepared food easily converted into vegetable juices.
The analysis and classification of soils is of the greatest importance to all those who take farms ; for the rent of land is very seldom pro portioned to its intrinsic value : one farm may be worth double the rent of another, where the apparent difference in the soil is very trifling. Those who have had long experience of the expense of cultivation, and the average produce of certain lands, can nearly guess what rent it may be safe to offer ; hut a stranger has no criterion to judge by. Hence it is notorious that a stranger coming to take a farm from a distant district is almost invariably deceived. Why should not the value of a soil be ascertainedAs readily as that of any article of commerce I If there were certain points of comparison, it would be so ; but in this the theory of agriculture is woefully deficient. A man
guesses at the qualities of land by the colour, the feeling, and other uncertain signs : it seldom or never occurs to a farmer to examine the component parts of a soil, by merely diffusing a portion in water, and testing the deposits—much less to compound artificial soils, and compare them with those found in the-fields. Yet every gardener can prepare soils suited to different plants, and make loams of all degrees of richness or consistence. In all these it will be found that sand, clay, chalk, and decayed vegetable substances, in various proportions, are the chief ingredients. If therefore these are found in a natural loam, we may safely conclude that it would be equally productive, and the deficiency of one ingredient may be supplied artificially. This would be going rationally and scientifically to work; and the result would be a more certain and satisfactory practice of husbandry.