TRACES OF A PRE-INDIAN PEOPLE. 317
of the Atlantic coast States, are made of flint in some one of its many forms, as jasper, chert, chalcedony, agate, horn-stone, or they are of quartz. I do not deny that they are also of other materials, hut that more than ninety-nine hundredths are of this material flint. In the valley of the Delaware River there are found, also, enormous numbers of similar objects, of quite uniform pattern and rudely finished, made of a mineral characteristic of the locality argillite. This term, " ar- gillite," as employed by Professor M. E. Wadsworth, of Cambridge, Massachusetts, to whom specimens of implements were submitted for examination, is used to designate all argillaceous rocks in which the argillaceous material is the predominant characteristic ; slate, or clay- slate, clay-stone, etc., are simply varieties of it, the term " slate " being only rightfully used when slaty cleavage is developed. The argillite out of which these specimens were made has no trace of cleavage.
The question may now very pertinently be asked, Why may not the Indians have used both minerals, flint and argillite, the one as fre- quently as the other ?
There are no reasons why, indeed, they might not have done so ; but, on the other hand, evidences that they did not are not wanting, if the circumstances under which the objects are found have been rightly interpreted.
The celebrated Swedish naturalist, Peter Kahn, traveled through- out Central and Southern New Jersey in 1748-50, and in his de- scription of the country remarks : * " We find great woods here, but, when the trees in them have stood a hundred and fifty or a hundred and eighty years, they are either rotting within, or losing their crown, or their wood becomes quite soft, or their roots are no longer able to draw in sufficient nourishment, or tbey die from some other cause. Therefore when storms blow, which sometimes happens here, the trees are broke off either just above the root or in the middle or at the summit. Several trees are likewise torn out with their roots by the power of the winds. ... In this manner the old trees die away continually, and are succeeded by a younger generation. Those which are thrown down lie on the ground and putrefy, sooner or later, and by that means increase the black soil, into which the leaves are likewise finally changed, which drop abundantly in autumn, are blown about by the winds for some time, but are heaped up and lie on both sides of the trees which are fallen down. It requires several years before a tree is entirely reduced to dust."
This quotation from Kahn has a direct bearing on that which fol- lows. It is clear how, to a great extent, the surface-soil was formed during the occupancy of the country by the Indians. The entire area of the State was covered with a dense forest, which, century after century, was increasing the black soil to which Kahn refers. If, now,
- " Travels into North America," by Peter Kahn (English translation), London, 1771,
vol. ii, p. IS.