of his crops, a judicious rotation, and his general ex perience will teach him, where and when he may economize with profit. He must not, however, gorge his land with manure, without rest or rotation, but seek to make it just rich enough to produce the most profitable crops. Should too much manure be applied, which, however, is rarely the case in vegetable culture, there will be loss of the most costly manurial ingredientnitrogen. Location, or want of facilities and means, frequently confines the gardener to forced limits. Those who are neither conveniently located for the purchase of stable manure, nor own sufficient stock to secure from their droppings a sufficiency of barn-yard manure, must have recourse to manurial agents to be named hereafter. Astonishing results are frequently seen in gardens near large cities, from the readiness such localities offer for procuring the best manures.

Agriculture being the foundation of the prosperity of every people, and successful agriculture being impossible in the present condition of the earth's surface without fertilizers, it has properly been said, that "manure, even more than money, forms an integral part of a nation's wealth."

When civilized nations properly appreciate the value of all manurial substances (as they will when their territory becomes as densely populated as China), none of these, as at present, will be allowed to go to waste, and the productiveness of the earth, and with it the wealth of nations, will be enormously increased. Progress in this direction is being made. Scientific men have pointed out the sanitary and economical necessity of dealing properly with excrementitious manurial substances. If, during the past century, the night-soil of many of our cities had been incorporated in the surface soil of the surrounding country, instead of being buried under the houses of their citizens, what would be the fertility

of the soil, and what the probable benefit to the sanitary condition of the cities?

Manures are either organic or inorganic, according as they may owe their composition to the animate or inanimate world, or are derived from vegetable and animal matters of all kinds, or from minerals.

Every kind of matter which, when added to the soil, promotes the growth of a plant, whether by being itself directly taken up by its roots, or by chemically altering any heretofore existing constituent of the soil, so that it may be made available, or by physically altering its texture, may be considered a manure or fertilizer. Every plant consists principally of the gaseous elements, nitrogen, oxygen, and hydrogen, and of carbon in varying proportions, and smaller quantities of alkalies, earths, silica, sulphur, and phosphorus. Chemical analysis has enabled us to learn the exact proportions of the constituents of plants, as well as the composition of soils. If chemical forces were the only forces of nature concerned in the growth of plants, then by supplying the soil with exactly the constituents in definite quantities, which chemical analysis has shown it to lack for the full maturity of any given agricultural crop, rules and formulas could be devised, so as to insure regularly the maximum yields of all crops. But the changes, not yet fully understood, constantly going on within the soil and upon its surface in contact with the atmosphere; the mutual chemical reactions of the various soils and fertilizing materials, and the vital actions of plants, with their influence upon the soil in which they grow, perhaps even upon the surrounding air, still more inexplicable and wonderful, together with the contingencies of weather, render it impossible to formulate any such rules. Exclusive of the crushing effects of glaciers and other agencies, under the gradual influence of water and the atmosphere, the surface of the rocks have become sufficiently pulverized

and comminuted to support lichens and other of the lowest forms of vegetation, which, by their decay increased the film of soil. These were followed by plants of a higher organization, successive generations preparing for those which followed them. Thus organic constituents accumulated, until, in time, every arable soil contained in varying proportions every element of plant food. The variations are such, however, that a soil in its natural or original condition may be more or less deficient in one or other constituent, and therefore be better adapted for one crop than another. Finding from experience or analysis, which of the principal constituents is absent in a soil, we may supply it by the application of a special fertilizer for the production of a particular crop.

Humus, or vegetable matter undergoing decay, which gives the dark color to fertile soils, disintegrates mineral substances, supplies large quantities of carbonic acid, ammonia, and nitrates, and is indispensable to fertility; and yet the direct absorption of humic matters into plants is by no means so well established, as not to be a mooted question between the best chemical authorities and vegetable physiologists.

Ammonia and nitric acid have been shown to be present in the air; but it is generally held that the soil must absorb these, or they must be conveyed to it in rain water, before they can be generally appropriated by plants. Yet Peters and Sachs proved, experimentally, that a bean plant grew and flourished by direct absorption of ammonia through its foliage alone; but they failed with every plant but the bean, which, like our cow pea, is a leguminous plant. Chemical analysis shows that the leguminosæ are richer in nitrogenous matter than any other family of plants, and yet we know that our cow pea will grow on the poorest soil, deriving its nourishment in part from the atmosphere. Ozone, or active oxygen, is

emitted by plants, and the more abundant the foliage, the greater the quantity. By the action of this ozone, the nitrogen of the air may be converted into nitric acid. Perhaps the cow pea, the clover, etc., are more active in this respect than any other plants.

These preliminary observations bring me to the first and most simple and cheapest manner of conveying fertility to the soil.

GREEN MANURING.

As soon as life is extinct, all organic substances begin to decay, and the richer these substances are in albuminoids, or such as contain nitrogen, the better are they adapted for fertilizing, and the more rapid will be the process of decay. Under like circumstances, albuminoids of animal origin will decompose more rapidly than those of vegetable origin. All green succulent plants containing saccharine and mucilaginous matters and woody fibre, ferment readily, hence the advantage of plowing in green crops, whether of natural growth, or sown for the purpose. No plant is better adapted to be used at the South for restoring fertility by green manuring than our cow pea. The analyses here given show it to be rich in albuminoids; it makes in our climate a heavier growth than clover in any part of the world, and grows on soil much too poor for a fair crop of the latter, answering thus both the demands of quality and quantity. When plants are in flower, they contain the largest quantity of soluble matter; it is, therefore, when plowed under at this season, under ordinary circumstances, that they will afford the greatest amount of soluble nutritive matter.

In heavy, impervious soils, especially, they should not be turned under too deeply, or else the absence of air will retard decomposition. No applications of commercial fertilizers will continuously prove beneficial without the presence, in the soil, of decaying vegetable matter, or hu

mus, and green manuring is the most efficacious and cheapest manner of supplying the land with large quantities of this necessary ingredient.

It should be practised by gardeners, irrespective of the supply of stable manure they may be able to command. But for those located at a distance from cities, and therefore not able to secure a sufficiency of barn-yard manure, green manuring becomes an absolute necessity.

It has been estimated that after the removal of a crop of clover and other plants, there remained in the soil, as shown in the following tables, a large amount of roots:

TABLE SHOWING THE QUANTITY OF ROOTS LEFT IN THE GROUND AFTER HARVESTING THE CROPS-ALSO THE AMOUNT OF NITROGEN AND ASH.

ANALYSIS OF THE ASH OF THE ROOTS IN THE FOREGOING TABLE.

No. of lbs. of
Nitrogen per

acre.

CarNo. of lbs. of Ash free bonic Acid, from

per acre.