The foregoing facts furnish us the data necessary to decide what influence permanent soil improvements have on the rent of land.[157-8] The improved parcels of land now grow more fertile. Their rentability also increases, while that of the others becomes not only relatively but absolutely less, if the demand remains unaltered. The whole is as if capital had been transformed into fertile land, and this added to the improved land. [Footnote 157-1: Since it has seemed absurd to many writers to say that an improvement in the art of agriculture may cause rents to decline (compare _Malthus_, Principles, I, ch. 3, 8), _John Stuart Mill_, Principles, IV, ch. 3, § 4, prefers to put the question thus: whether the landowner is not injured by the improvement of the estates of other people, although his own is included in the improvement. Compare _Davenant_, Works, I, 361. And so the long agricultural crisis through which Germany passed at the beginning of the third decade of this century was produced mainly by the great impulse given to agriculture (_Thaer_, _Schuerz_ etc.), while population did not keep pace with it. Similarly, at the same time, in England, _McCulloch_, Stat., I, 557 ff. Of course, the less fertile pieces of land declined even relatively most in price. From 1654 to 1663, Switzerland experienced a severe agricultural crisis, attended with oppressive cheapness of corn, a great decline in the price of land, innumerable cases of insolvency, revolts of the peasantry, emigration, etc. (_Meyer von Knonau_, Handbuch d. schweiz. Gesch., II, 43.) The Swiss had, precisely during the Thirty Years' War which spared them, so extensively developed their agricultural interests, that now that other countries began to compete with them, they could not find a market large enough for their products. For English instances of similar "agricultural distress" in the seventeenth and eighteenth centuries, see _Child_, Discourse on Trade, 73, 124 seq.; _Temple_, Observations upon the U. P., ch. 6; _Tooke_, History of Prices, I, 23 seq., 42. Even where there have been no technic improvements, a series of unusually good harvests may have the same results, of which there are many instances scattered through _Tooke's_ first volume. There is great importance attached in England to the difference between those agricultural reforms which save land and those which effect a saving in capital and labor. The latter, it is said, decrease the money rent of the landowner by depreciating the price of corn, but leave the corn-rent unaltered. The former, on the other hand, decrease the rent both in money and corn, but the money rent in a higher degree. (_Ricardo_, Principles, ch. 2; _J. S. Mill_, Principles, IV, ch. 3, 4.)]