But though many of those western wilderness immigrants were "poor pilgrims" and for a time squatters (as the immediately extramural population of Paris), they were recruited from the sturdiest stock on the Atlantic side of the fortifications. Some went, to be sure, who had failed in the old place, but were ready to make new hazard; some wanted greater freedom than the more highly socialized and conventionalized life within the fortifications would permit; some longed for adventure; some sought a fortune or competency perhaps impossible in the old settlements; some had only the inherited promptings of the nomad savage in them, and kept ever moving on, making their nameless graves out in the gloom of the forest or upon the silent plains. It was indeed a motley procession, the by-product of the more or less conservative, sometimes politically or religiously intolerant, aristocratic tide-water settlements. Yet do not make the mistake of thinking that it was slag or refuse humanity, such as camps in the narrow zone around the gates of Paris. It is rather like an industrial by-product that has needed some slight change or adaptation to make it more valuable to society than the original product upon which the manufacturers had kept their attention fixed--or, at any rate, to make the margin of profit in the whole industry greater. Out of once discarded, seemingly valueless matter have come our coal-tar products: saccharine many times sweeter than sugar, colors unknown to the old dyers, perfumes as fragrant as those distilled from flowers, medicines potent to allay fevers. Up in the woods of Canada last summer I found a chemist trying to do with the wood waste what Remsen and Perkin and others have done with coal waste, and I cannot resist the suggestion of my metaphor that there in the forest valleys beyond the Alleghanies the elements and conditions were found to convert this Atlantic by-product, unpromising outwardly, into the substance of a new and precious civilization. This overmountain procession came chiefly up the watercourses of the south and middle States. Prior to 1830 the mass of pioneer colonists in most of the Mississippi Valley had been contributed by the up-country of the south. The dominant strain in those earlier comers, as President Roosevelt reminds us, was Scotch-Irish, a "race doubly-twisted in the making, flung from island to island and toughened by exile"--a race of frontiersmen than whom a "better never appeared"--a race which was as "steel welded into the iron of an axe." They form the kernel of the "distinctively and intensely American stock who were the pioneers of the axe and the rifle, succeeding the French pioneers of the sword and the bateaux."