To the Editor: Sir,--It has now become an axiom with all liberal thinkers that complete freedom of exchange between nations and countries of the various products each has in superabundance and can best spare, for others which it requires, is for the benefit of both parties; and this principle is thought to be so universally applicable, that even when it produces positive injury to ourselves and is certain to injure our descendants, hardly any public writer who professes liberal views ventures to propose a limitation of it. It seems clear, however, that there are limitations to its wholesome application, and that there are certain commodities which we have no right to exchange away without restriction, for others of more immediate use to the individuals or communities who happen to be in possession of them. These commodities may be briefly defined as those natural products which are practically limited in quantity, and which cannot be reproduced. What is meant may perhaps be best explained by taking what may be considered a very extreme case as an illustration. Let us suppose, for instance, a country in which the springs or wells of water were strictly limited in number, but sufficiently copious to supply all the actual needs of the community who had always had the use of them, on making a nominal payment to the owners of the land on which they were situated. Acting on the principles of unrestricted free trade, and anxious to increase their wealth, one after another of the landowners sold their springs to manufacturers, who used up all the water except that required to supply the wants of their own workpeople, thus rendering the remainder of the country almost uninhabitable. A still more extreme case, but one rather more to the point, would be that of a country possessing a surface soil of very moderate depth, but of extreme fertility, and supporting a dense population on its vegetable products. The landowners might find it very profitable to them to sell this surface soil to the wealthy horticulturists of other countries; and if the principle of free trade is unlimited, they would be justified in doing so, although they would permanently impoverish the land, and render it capable of supporting a less numerous and less healthy population in long future ages.

    Most persons will admit that in both these cases the exercise of the unrestricted right of free trade becomes a wrong to mankind, and should on no account be permitted; and it will perhaps be said that such cases could never occur in a civilized community, as public opinion would not allow the landowners to act in the manner indicated even were they disposed to do so. I believe, however, it may be shown that, under circumstances far worse than those here supposed, the landowners in the most civilized community on the globe do act in a very analogous manner, and, moreover, are not yet condemned by public opinion for doing so. Let us first, however, deduce from such supposed cases as those above given a general principle determining what articles of merchandise are and what are not the proper subjects of free trade. A little consideration will convince us that most animal or vegetable products or manufactured articles, the reproduction and increase of which are almost unlimited in comparatively short periods, are those whose free exchange is an unmixed benefit to mankind; the reason being that such exchange enriches both parties without impoverishing either, and, by leading to improved modes of cultivation and an increased power of production, adds continually to the sustaining power of the earth, and benefits future generations as much as it does ourselves. On the other hand, all those articles of consumption which are in any way essential to the comfort and well-being of the community, and which are, either absolutely or practically, limited in quantity and incapable of being reproduced in any period of time commensurate with the length of human life, are in a totally different category. They must be considered to be held by us in trust for the community, and for succeeding generations. They should be jealously guarded from all waste or unnecessary expenditure, and it should be considered (as it will certainly come to be regarded) as a positive crime against posterity to expend them lavishly for the sole purpose of increasing our own wealth, luxury, or commercial importance. Under this head we must class all mineral products which are extensively used in domestic economy, the arts or manufactures, and which are in any way essential to the health or well-being of the community, and more especially those which from their bulk, weight, and extensive use could not be imported from distant regions without a very serious addition to their cost, such as is pre-eminently the case with coal and iron.

    Now, it will be seen that we have here to deal with a case quite as extreme in reality as those supposititious cases with which we commenced this inquiry. For coal and iron are almost as much necessaries of life to the large population of this country as are abundance of water and a fertile soil; but there is this difference, that the water might be restored to its legitimate use, and the soil might be renewed by a sufficient period of vegetable growth; whereas coal burned, and iron oxydised, are absolutely lost to mankind, and we have no knowledge of any restorative processes except after the lapse of periods so vast that they cannot enter into our calculations. It may be replied, that the quantity existing on the globe is vast enough for the necessities of mankind for any periods we need calculate on; but even if this be so (of which we are by no means certain), it may none the less be shown that numerous and wide-spread evils result from our present mode of recklessly expending the stores in certain countries, while the same products remain totally unused in many of the countries they are exported to. For a number of years we have been increasing our production of coal and iron at an enormous rate, and sending vast quantities of both to all parts of the world, civilized and uncivilized, and have thereby produced, so far as I can see, little but evil in various forms, some of which have hitherto received little attention.

    Briefly to state these:--In the first place, we have seriously, and perhaps permanently, increased the cost of one of the chief necessaries of life in so changeable a climate as ours--fuel. This is in itself so great and positive an evil that no considerations of mere convenience to remote nations, such as the construction of railways in New Zealand or in Honduras, ought even to be mentioned as an excuse for it. Coal in winter is a question of comfort or misery, even of life or death, to millions of the people whose happiness it is our first duty to secure; and shall we coolly tell them that the Antipodes must have railroads, and that landowners, coalowners, and contractors must make fortunes, although the necessary consequence is the yearly increasing scarcity of one of their first necessaries and greatest comforts?

    In the second place, by destroying for ever a considerable and ever-increasing proportion of the mineral wealth of our country, we have rendered it absolutely less habitable and less enjoyable for our descendants, and we have not done this by any fair and justifiable use for our own necessities or enjoyments, but by the abuse of increasing to the utmost of our power the quantity we send out of the country, never mind for what purpose, so that it adds to the wealth of our landowners, capitalists, and manufacturers.

    In the third place, we have brought into existence a large population wholly dependent on this excessive production and export of minerals, and therefore not capable of being permanently maintained on our soil. In proportion as other nations make use of their mineral productions, and as our own minerals, from the increasing difficulty of procuring them, become necessarily more costly, so must our excessive exports diminish, and with it must diminish our power of maintaining our present abnormal population. A period of adversity will then probably set in for us, only faintly foreshadowed in intensity and duration by those arising from mere temporary fluctuations in the demand for minerals and their manufactured products.

    Fourthly, we not only injure ourselves and our successors by thus striving to get rid of our mineral treasures as fast as possible, but we probably do more harm than good to the nations to whom we export them; for we prevent them from deriving the various social and intellectual benefits which would undoubtedly arise from their being compelled to utilise for their own purposes the mineral products of their own lands. The working of mines and the establishment of manufactures bring into action such a variety of the mental faculties, and so well vary and supplement the labours and the profits of agriculture or trade, that a people who wholly neglect these branches of industry can hardly be said to live a complete and healthy national life. By considering our rich stores of coal and iron as held in trust by us for the use of the present and future populations of these islands, we should probably stimulate and advance a healthy civilization in many countries which the most lavish expenditure of our own minerals, aided by our capital and engineering skill, fail to benefit.

    Lastly, I would call attention to the way in which the lavish production of minerals disfigures the country, diminishes vegetable and animal life, and destroys the fertility (for perhaps hundreds of generations) of large tracts of valuable land. It would be interesting to have a survey made of the number of acres of land covered by slag-heaps and cinder-tips at our iron and copper works, and by the waste and refuse mounds at our various mines and slate quarries, together with the land destroyed or seriously injured by smoke and deleterious gases in those "black countries" which it pains the lover of nature to travel through. The extent of once fertile land thus rendered more or less permanently barren would, I believe, astonish and affright us. How strikingly contrasted, both in their motive and results, are those noble works of planting or of irrigation which permanently increase both the beauty and productiveness of a country, and carry down their blessings to succeeding generations.

    This brief sketch of some of the more salient features of the subject of mineral export will serve to show how many and various are the evil results which flow from allowing these invaluable treasures to be wasted at the dictates of mad speculation and the eager race for wealth. These considerations have a very practical bearing at the present time. The recent enormous rise in the price of coal has brought up the question of the advisability of an export duty upon it. The press, almost without exception, have opposed this as being "contrary to the principles of free trade;" and it has further been argued that such a duty would have little or no effect, because the real cause of the high price of coal is that so much is used in the excessive manufacture of iron. But it is evident, from the considerations here set forth, that the export both of coal and iron requires to be regulated or forbidden, and for the same reasons; and if the "principles of free trade" are opposed to this, so much the worse for those "principles," since they will be opposed not only to the true economy of human progress, but also to the clearest principles of social and national morality. Many persons will now ask whether those can be true principles which lead to the exhaustion of our coal-fields for the purpose of lighting South American cities with gas or building railways in every insolvent South American Republic, while our own hard-working population has to suffer the pangs of cold in winter, in consequence of the high price of coal which such reckless projects tend to cause. And the fact that all parties concerned--landowners, colliery proprietors, speculators, and legislators--are so far from seeing anything wrong in what they are doing that their one aim at the present moment is to secure a larger annual output, and an increased export, will be to many an additional argument for taking the property in land altogether out of private hands. Waiving that question, however, for the present, I maintain that it is a wrong to our own population, and a still greater wrong to the next generation, to permit the unlimited export of those mineral products which are absolute necessaries of life, but which once destroyed we can never reproduce. To do so is to sell and alienate for ever a portion of our land itself, and should no more be permitted to private individuals than the selling of the land surface to a foreign State.

    Whether or not the period of the total exhaustion of our coal-fields can be approximately estimated, it is clear that the present vast and increasing rate of consumption must be stopped. The numerous evils of the present system I have briefly indicated--where are the benefits which counter-balance them? And the benefits, if they exist, must be large and clear and positive indeed to justify us in recklessly scattering over the whole world the mineral products of our land. It is to their possession that we attribute much of our wealth and power and national prosperity, yet we are doing our best to deprive future generations of any of the advantages we have derived from them.

    It appears, then, to be clearly our duty to check the further exhaustion of our coal supplies by at once putting export duties on coal and iron in every form, very small duties at first, so as not to produce too sudden a check on the employment of labour, but gradually increasing, till, by stimulating an increased production in other countries, they may no longer be required. If other nations should see the wisdom and justice of following our example, each may in future develop and enjoy its own mineral products, may help to supply what is necessary to the welfare of those countries which do not possess these natural gifts, and may still leave an ample supply to their descendants.