Iron, the metal which the Indians worshipped as a spirit when they first saw it in the hands of the French, a substance so precious that their name for it meant "all kinds of good," has, too, been taken with feverish haste from its ancient places. Joliet and Marquette saw deposits of this ore near the mouth of the Ohio in 1673, but it was a century and a half before the harvesting of this crop, down among the rocks for millions of years before, began. And now, if no new fields are found and the increased use goes on at the rate of the last three decades, all the available high- grade ore will have become pig iron and steel billets, bridges, battle- ships, sky-scrapers, and locomotives, and all kinds of goods, within the next three decades. [Footnote: Van Hise, p. 68.] The forests of the United States--the forests primeval, with the voice of whose murmuring pines and hemlocks Longfellow begins his sad story of the Acadians--contained approximately one billion acres, [Footnote: Van Hise, p. 210.] a region not conterminous with, but almost as large as, the Mississippi Valley. Of that great, tempering, benign shadow over the continent, tempering its heat, giving shelter from its cold, restraining the waters, there is left about 65 per cent in acreage and not more than one-half the merchantable timber--five hundred million acres gone in a century and a half. [Footnote: Van Hise, p. 210.] And as to the land itself--the land first symbolized in the tuft of earth that St. Lusson lifted toward the sky that day in 1671 at Sault Ste. Marie, when he took possession of all the land between the seas of the north and west and south--in the first place, the loss each year from erosion is six hundred and ten million cubic yards. [Footnote: Van Hise, p. 307, quoted from W. J. Spillman, "Report National Conservation Commission," 3:257-262.] This is, of course, inconsiderable in a short period but in a long period of years means a mighty loss of nourishing soil. With this loss is that of nitrogen, potassium, and phosphorus, things of which the farmer had not even heard the names a few years ago. The yield of farms in the United States during the last forty years does not show a decreased average, but it must be remembered that in this period there have been brought under cultivation new and virgin acres, which have in their bountiful yield kept up the general average. One authority says that, taking the country by regions and by districts and considering what has actually happened, he is led to the conclusion that the fertility of the soil for 50 per cent of our country has been lessened. [Footnote: Van Hise, p. 299.] The significance of these facts lies in the desire of the people to know the truth and seek a remedy.