If we suppose, that the real price of corn is unchangeable, or not capable of experiencing a relative increase or decrease of value, compared with labour and other commodities, it will follow, that agriculture is at once excluded from the operation of that principle, so beautifully explained and illustrated by Dr Smith, by which capital flows from one employment to another, according to the various and necessarily fluctuating wants of society. It will follow, that the growth of corn has, at all times, and in all countries, proceeded with a uniform unvarying pace, occasioned only by the equable increase of agricultural capital, and can never have been accelerated, or retarded, by variations of demand. It will follow, that if a country happened to be either overstocked or understocked with corn, no motive of interest could exist for withdrawing capital from agriculture, in the one case, or adding to it in the other, and thus restoring the equilibrium between its different kinds of produce. But these consequences, which would incontestably follow from the doctrine, that the price of corn immediately and entirely regulates the prices of labour and of all other commodities, are so directly contrary to all experience, that the doctrine itself cannot possibly be true; and we may be assured, that, whatever influence the price of corn may have upon other commodities, it is neither so immediate nor so complete, as to make this kind of produce an exception to all others.

That no such exception exists with regard to corn, is implied in all the general reasonings of the Wealth of nations. Dr Smith evidently felt this; and wherever, in consequence, he does not shift the question from the exchangeable value of corn to its physical properties, he speaks with an unusual want of precision, and qualifies his positions by the expressions much, and in any considerable degree. But it should be recollected, that, with these qualifications, the argument is brought forward expressly for the purpose of showing, that the rise of price, acknowledged to be occasioned by a bounty, on its first establishment, is nominal and not real. Now, what is meant to be distinctly asserted here is, that a rise of price occasioned by a bounty upon the exportation or restrictions upon the importation of corn, cannot be less real than a rise of price to the same amount, occasioned by a course of bad seasons, an increase of population, the rapid progress of commercial wealth, or any other natural cause; and that, if Dr Smith's argument, with its qualifications, be valid for the purpose for which it is advanced, it applies equally to an increased price occasioned by a natural demand.

Let us suppose, for instance, an increase in the demand and the price of corn, occasioned by an unusually prosperous state of our manufactures and foreign commerce; a fact which has frequently come within our own experience. According to the principles of supply and demand, and the general principles of the Wealth of nations, such an increase in the price of corn would give a decided stimulus to agriculture; and a more than usual quantity of capital would be laid out upon the land, as appears obviously to have been the case in this country during the last twenty years. According to the peculiar argument of Dr Smith, however, no such stimulus could have been given to agriculture. The rise in the price of corn would have been immediately followed by a proportionate rise in the price of labour and of all other commodities; and, though the farmer and landlord might have obtained, on an average, seventy five shillings a quarter for their corn, instead of sixty, yet the farmer would not have been enabled to cultivate better, nor the landlord to live better. And thus it would appear, that agriculture is beyond the operation of that principle, which distributes the capital of a nation according to the varying profits of stock in different employments; and that no increase of price can, at any time or in any country, materially accelerate the growth of corn, or determine a greater quantity of capital to agriculture.

The experience of every person, who sees what is going forward on the land, and the feelings and conduct both of farmers and landlords, abundantly contradict this reasoning.

Dr Smith was evidently led into this train of argument, from his habit of considering labour as the standard measure of value, and corn as the measure of labour. But, that corn is a very inaccurate measure of labour, the history of our own country will amply demonstrate; where labour, compared with corn, will be found to have experienced very great and striking variations, not only from year to year, but from century to century; and for ten, twenty, and thirty years together;(1*) and that neither labour nor any other commodity can be an accurate measure of real value in exchange, is now considered as one of the most incontrovertible doctrines of political economy, and indeed follows, as a necessary consequence, from the very definition of value in exchange. But to allow that corn regulates the prices of all commodities, is at once to erect it into a standard measure of real value in exchange; and we must either deny the truth of Dr Smith's argument, or acknowledge, that what seems to be quite impossible is found to exist; and that a given quantity of corn, notwithstanding the fluctuations to which its supply and demand must be subject, and the fluctuations to which the supply and demand of all the other commodities with which it is compared must also be subject, will, on the average of a few years, at all times and in all countries, purchase the same quantity of labour and of the necessaries and conveniences of life.

There are two obvious truths in political economy, which have not infrequently been the sources of error.

It is undoubtedly true, that corn might be just as successfully cultivated, and as much capital might be laid out upon the land, at the price of twenty shillings a quarter, as at the price of one hundred shillings, provided that every commodity, both at home and abroad, were precisely proportioned to the reduced scale. In the same manner as it is strictly true, that the industry and capital of a nation would be exactly the same (with the slight exception at least of plate), if, in every exchange, both at home or abroad, one shilling only were used, where five are used now.

But to infer, from these truths, that any natural or artificial causes, which should raise or lower the values of corn or silver, might be considered as matters of indifference, would be an error of the most serious magnitude. Practically, no material change can take place in the value of either, without producing both lasting and temporary effects, which have a most powerful influence on the distribution of property, and on the demand and supply of particular commodities. The discovery of the mines of America, during the time that it raised the price of corn between three and four times, did not nearly so much as double the price of labour; and, while it permanently diminished the power of all fixed incomes, it gave a prodigious increase of power to all landlords and capitalists. In a similar manner, the fall in the price of corn, from whatever cause it took place, which occurred towards the middle of the last century, accompanied as it was by a rise, rather than a fall in the price of labour, must have given a great relative check to the employment of capital upon the land, and a great relative stimulus to population; a state of things precisely calculated to produce the reaction afterwards experienced, and to convert us from an exporting to an importing nation.

It is by no means sufficient for Dr Smith's argument, that the price of corn should determine the price of labour under precisely the same circumstances of supply and demand. To make it applicable to his purpose, he must show, in addition, that a natural or artificial rise in the price of corn, or in the value of silver, will make no alteration in the state of property, and in the supply and demand of corn and labour; a position which experience uniformly contradicts.

Nothing then can be more evident both from theory and experience, than that the price of corn does not immediately and generally regulate the prices of labour and all other commodities; and that the real price of corn is capable of varying for periods of sufficient length to give a decided stimulus or discouragement to agriculture. It is, of course, only to a temporary encouragement or discouragement, that any commodity, where the competition is free, can be subjected. We may increase the capital employed either upon the land or in the cotton manufacture, but it is impossible permanently to raise the profits of farmers or particular manufacturers above the level of other profits; and, after the influx of a certain quantity of capital, they will necessarily be equalized. Corn, in this respect, is subjected to the same laws as other commodities, and the difference between them is by no means so great as stated by Dr Smith.