more liberal assistance from the accumulated vegetative forces, on which no draft has yet been made. The additional work which the community has obtained by the transfer of power from exchange to production, is done under more favourable circumstances and with better machinery.

We do not design to renew the discussion of the Ricardo doctrine of Rent. Trusting that the reader is satisfied of its incorrectness, and concurs in the belief that the last labour spent upon the land is, so far as it depends upon the laws of Nature, the most profitable instead of the least, we, nevertheless, invite his attention to some considerations, the validity of which does not depend in any degree upon the truth of that doctrine or of its opposite. It is proper, however, to remind him, that Mr. Ricardo recognises "advantages of situation" as equivalent in all respects to fertility of soil. Advantages of situation consist in nothing else than greater facility, or smaller necessity, for transportation. Mr. Mill is explicit in the admission, that such is the meaning of the words. "Land may be inferior," he remarks, "either in fertility or in situation. The one requires a greater proportional amount of labour for growing the produce; the other for carrying it to market." He repeats, after a few sentences: "Inferior lands, or lands at a greater distance from the market, of course yield an inferior return; and an increasing demand cannot be supplied from them unless at an augmentation of cost, and, therefore, of price."* Again, after the interval of a page, the same idea is reiterated: "Only when no soils remain to be broken up, but such as, either from distance or inferior quality, require a considerable rise of price to render their cultivation profitable, can it become advantageous to apply the high farming of Europe to any American lands; except, perhaps, in the immediate vicinity of towns, where saving in cost of carriage may compensate for great inferiority in the return from the soil itself." Now, it will not escape observation, that one of these causes of diminished return from land is directly antagonistic to the other. The same increase in agricultural population which drives the last comers to inferior lands diminishes the intervals between them.

This is a general

* Political Economy, vol. 1, page 215.

objection to the doctrine. In regard to its application to the particular question in dispute, it is enough to remark, that however distant the producers from the consumers within their country, they will at all events be nearer than if the latter were in another country, and will therefore have gained advantages of situation by the transfer. There is, however, no necessity of determining how far one of the conflicting elements, which, according to the Ricardo hypothesis, affect production, may counterbalance the other. The system of foreign trade, of itself, necessarily tends to impoverish the land already under cultivation, to reduce it to a lower grade of fertility, or, what is the same thing, to require a greater outlay of labour and capital, in order to maintain its rate of production. We have seen that the process of growth is but a part of the process of circulation; that no new material is created under the action of the vegetative forces; but that they simply elaborate one form of matter out of others. The soil continues to produce, only upon the condition that whatever is taken from its surface shall be returned to it in some form or another. Every crop is made from matter furnished by its predecessors; and whatever is lacking in the manure will surely, sooner or later, disappear in the product. Exhaustion and renovation must reciprocate in equal measure. If any element, however minute in quantity, is constantly withdrawn and removed from the soil, the product of which it is a constituent must finally cease to reappear. If animals are fed upon the land, their excrements restore a large portion of the inorganic matter, of which the plants on which they feed have robbed the soil. But the richest pasture will, after a time, show signs of exhaustion, if the young cattle that grow upon it are sent to distant markets. Let the cattle remain, and their manure be faithfully restored: if they are cows, a considerable quantity of phosphate of lime is contained in their milk; and if this is sent away in its original form, or in the shape of butter and cheese, the soil must cease to furnish pasture which will make milk. The grass lands of Cheshire, in England, famous for its dairy husbandry, were thus impoverished. They were restored by the application of ground bones-human bones, in a great measure, imported from the battle-fields of the continent-which contain essentially the same substances as the milk. The importance of what might seem an

insignificant loss to the land, is shown by the fact stated by Prof. Johnston, that lands which paid but five shillings an acre of rent, have been, by restoring the bone phosphates, of which they had been ignorantly robbed, made to yield a rent of forty shillings, besides a good profit to the dairyman. Different crops take away the inorganic substances of the soil in different proportions; the grains, for instance, take chiefly phosphates; potatoes and turnips, mostly potash and soda; but all crops, natural or artificial, deprive the land of some essential ingredient, and, in whatever shape the ingredient is finally removed, in animal or human muscle and bones, in cloth made from the cotton, the wool, or the flax, boots or hats made from the skin or the fur of the animals, no matter how many transformations the elements may have undergone, the vegetative power of the earth from which they were withdrawn has been diminished to an equivalent extent. Nature is an easy creditor, and presents no bill of damages for exhausted fertility. We are, therefore, little accustomed to take account of what is due to the earth. An idea, however, of the great pecuniary magnitude of the debt, may be gained from the fact, that the manure annually applied to the soil of Great Britain, at its market prices, was estimated in 1850* at £103,369,139, a sum much exceeding the entire value of its foreign trade. In Belgium, which sustains a population of 336 to the square mileone to every arable acre in the kingdom-which, according to Mr. M'Culloch, "produces commonly more than double the quantity of corn required for the consumption of its inhabitants," and where immense numbers of cattle are stall-fed for the sake of their manure, the liquid excrements of a single cow sell for ten dollars a year. The people of Belgium are able, by making their own population, animal and human, the most dense of any country in the world, to raise beef, mutton, pork, butter, and grain, cheaply enough to admit of their exportation to England, to feed people who believe in over-population.

The necessity of taking into account the comparative exhaustion resulting from the growth and removal of different crops, as well as their comparative cheapness of transportation, modifies considerably

* Macqueen's Statistics, page 12.

the inferences which would otherwise be made in regard to their value. A work in which all the circumstances which can affect the economy of different modes of cultivation, are subjected to rigorous mathematical calculation*- the necessary elements being derived from exact accounts, kept by its author during fifteen years of superintendence of an agricultural school and model farm in Germany— supplies us with this illustration. Three bushels of potatoes, it is said, have been ascertained to possess the same amount of nutritive power as one bushel of rye—the standard with which all crops are compared by this writer. It is also stated that ground, equal in extent and of equal quality, will produce nine bushels of potatoes where it would yield but three of rye, while one bushel of the latter demands as much labour as 5% of the former. A given quantity of nutriment could therefore be obtained upon one-third the area of land, and with half the amount of labour, by the cultivation of potatoes, which would be required to produce it in the shape of rye. But in order to keep the soil in heart, so that it will continue to grow either rye or potatoes, a certain portion of the farm must be devoted to pasturage, that manure may be made. Taking into account the requirements in this respect of the two crops in question, it is found that the same area which suffices for the production of 39 measures of nutritive matter in rye, instead of producing three times that number in potatoes, yields but 64. The actual value of the two crops, instead of bearing the proportion of 100 to 300, has that of 100 to 164.

The above calculation proceeds upon the assumption, that the farm must manufacture and save its own manure. Every town, however, every hamlet where artizans are congregated, is a place whence the refuse of crops, after subserving human nutrition, may be removed with great advantage to the health of the inhabitants, and no detriment to the productiveness of their industry. The

* De Thünen: "RECHERCHES sur l'influences que LE PRIX DES GRAINS, LA RICHESSE DU SOL, ET LES IMPOTS exercent sur la culture," page 178. The work is only known to the writer in the French translation, made from the original German, under the auspices of the National and Central Agricultural Society of France.

sewer-water of large towns contains its refuse in a state of dilution, highly favourable to the growth of plants and the increase of fertility. "From every town of a thousand inhabitants," says Professor Johnston, "is carried annually into the sea, manure equal to 270 tons of guano, worth, at the then current price of guano in England, $13,000, and capable of raising an increased produce of not less than 1000 quarters of grain." It is alleged by competent engineers, that liquid manure can be distributed at a much less cost than that of carting an equal fertilizing value in a solid form. The drainagewater from a large portion of the city of Edinburgh has been conducted into a small brook, and made to overflow some three hundred acres of flat land, which is thus rendered so productive as to be sometimes mown seven times in a season. A portion of it, held under a long lease at £5 per acre, is sub-let at £30, and some of the richest meadows at even higher rates. Advantages of this character are the result of combination upon a large scale. The centres of population, however, supply manures which may be made immediately available by the individual farmer, with no other assistance than that of his own carts and horses. Whether it is more profitable to manufacture manure upon the farm, by devoting to that object portions of the land, which might otherwise grow crops for sale, or to procure the manure from town, depends upon the price which must be paid for it, and the distance to which it has to be The German agriculturist, to whom we before referred, has deduced the relation between the prices the farmer can afford to pay for fertilizing material at the town-for the purpose of growing potatoes with the same economy as if it were made from other crops upon the farm-and the distance it is to be transported. The result at which he arrives is, that a quantity of manure which would be worth $5 40, for the purpose of applying to land in the immediate suburbs of the town, or where the expense of cartage is so trifling that it may be disregarded, is worth $4 20, if the farm be one German mile (4.60 English miles) distant-$3 10, if the distance be two German miles $1 90, at three miles-83 cents at four; and that at the distance of 4 German, or about 22 English miles, he can pay nothing for it: though he may still carry it away as cheaply as to give up the growing of potatoes upon that portion