Mr. Bartram was at this time-building a house in Philadelphia, and had sunk a cellar to a considerable depth, the soil of which was thrown out. I here observed the following strata. The upper loose soil was only half a foot deep, and of a dark brown colour. Under it was a stratum of clay so much blended with sand, that it was in greater quantity than the clay itself; and this stratum was eight feet deep. These were both brick coloured. The next stratum consisted of little pebbles mixed with a coarse sand. The stones consisted either of a clear, or of a dark Quartz;[19] they were [[120]]quite smooth and roundish on the outside, and lay in a stratum which was a foot deep. Then the brick-coloured clay mixed with sand appeared again. But the depth of this stratum could not be determined. Query, could the river formerly have reached to this place and formed these strata?
Mr. Bartram has not only frequently found oyster-shells in the ground, but likewise met with such shells and snails, as undoubtedly belong to the sea, at the distance of a hundred and more English miles from the shore. He has even found them on the ridge of mountains which separate the English plantations from the habitations of the savages. These mountains which the English call the blue mountains, are of considerable height, and extend, in one continued chain from north to south, or from Canada to Carolina. Yet in some places they have gaps, which are as it were broke through, to afford a passage for the great rivers, which roll down into the lower country.
The Cassia Chamæcrista grew on the roads the woods, and sometimes [[121]]on uncultivated fields, especially when shrubs grew in them. Its leaves are like those of the Sensitive plant, or Mimosa, and have likewise the quality of contracting when touched, in common with the leaves of the latter.
The Crows in this country are little different from our common crows in Sweden. Their size is the same with that of our crows, and they are as black as jet in every part of their body. I saw them flying to day in great numbers together. Their voice is not quite like that of our crows, but has rather more of the cry of the rook, or Linnæus’s Corvus frugilegus.
Mr. Bartram related, that on his journeys to the northern English colonies, he had discovered great holes in the mountains on the banks of rivers, which according to his description, must exactly have been such giants pots,[20] as are to be met with in Sweden, and which I have described in a particular dissertation read in the Royal Swedish Academy of Sciences. Mr. Bartram has likewise addressed some letters to the Royal Society at London upon this subject. For [[122]]some people pretended, that these holes were made by the savages, that they might in time of war hide their corn and other valuable effects in them. But he wrote against this opinion, and accounted for the origin of these cavities in the following manner. When the ice settles, many pebbles stick in it. In spring when the snow melts, the water in the rivers swells so high that it reaches above the place where these holes are now found in the mountains. The ice therefore will of course float as high. And then it often happens, that the pebbles which were contained in it, ever since autumn when it first settled on the banks of the river, fall out of the ice upon the rocky bank, and are from thence carried into a cleft or crack by the water. These pebbles are then continually turned about by the water, which comes in upon them, and by this means they gradually form the hole. The water at the same time polishes the stone by its circular motion round it, and helps to make the hole or cavity round. It is certain that by this turning and tossing, the stone is at last unfit for this purpose; but the river throws commonly every spring other stones instead of it into the cavity, and they are turned round in the same manner. By this whirling both the mountain [[123]]and the stone afford either a fine or a coarse sand, which is washed away by the water when in spring, or at other times it is high enough to throw its waves into the cavity. This was the opinion of Mr. Bartram about the origin of these cavities. The Royal Society of Sciences at London, has given a favourable reception to, and approved of them.[21] The remarks which I made in the summer of the year 1743, during my stay at Land’s-Ort, in my country, will prove that I was at that time of the same opinion, in regard to these holes. I have since further explained this opinion in a letter to the Royal Academy of Sciences; and this letter is still preserved in the Academy’s Memoirs, which have not yet been published. But there is great reason to doubt, whether all cavities of this kind in mountains, have the same origin.
Here are different species of Mulberry trees, which grow wild in the forests of north and south America. In these parts the red mulberry trees are more plentiful than any other. However Mr. Bartram assured me that he had likewise seen the [[124]]white mulberry trees growing wild, but that they were more scarce. I asked him and several other people of this country, why they did not set up silk manufactures, having such a quantity of mulberries, which succeed so easily? For it has been observed that when the berries fall upon the ground where it is not compact but loose, they soon put out several fine delicate shoots. But they replied that it would not be worth while to erect any silk manufactures here, because labour is so dear. For a man gets from eighteen pence to three shillings and upwards, for one day’s work, and the women are paid in proportion. They were therefore of opinion that the cultivation of all sorts of corn, of hemp, and of flax, would be of greater advantage, and that at the same time it did not require near so much care as the feeding of silk worms. By the trials of a governor in Connecticut, which is a more northern province than New York, it is evident however, that silk worms succeed very well here, and that this kind of mulberry trees is very good for them. The governor brought up a great quantity of silk worms in his court yard; and they succeeded so well, and spun so much silk, as to afford him a sufficient quantity for cloathing himself and all his family. [[125]]
Several sorts of Vines likewise grow wild hereabouts. Whenever I made a little excursion out of town, I saw them in numerous places climbing up trees and hedges. They clasp around them, and cover them sometimes entirely, and even hang down on the sides. This has the same appearance at a distance, as the tendrils of hops climbing along trees. I enquired of Mr. Bartram why they did not plant vineyards, or press wine from the grapes of the wild vine. But they answered, that the same objection lay against it, which lies against the erection of a silk manufacture, that the necessary hands were too scarce, and it therefore was more rational to make agriculture their chief employment. But the true reason undoubtedly is, that the wine which is pressed out of most of the North American wild grapes is sour and sharp, and has not near such an agreeable taste, as that which is made from European grapes.
The Virginian Wake robin, or Arum Virginicum, grows in wet places. Mr. Bartram told me, that the savages boiled the spadix and the berries of this flower, and devoured it as a great dainty. When the berries are raw, they have a harsh, pungent [[126]]taste, which they lose in great measure upon boiling.
The Sarothra Gentianoides, grows abundantly in the fields and under the bushes, in a dry sandy ground near Philadelphia. It looks extremely like our whortleberry bushes when they first begin to green, and when the points of the leaves are yet red. Mr. Bartram has sent this plant to Dr. Dillenius, but that gentleman did not know where he should range it. It is reckoned a very good traumatic, and this quality Mr. Bartram himself experienced; for being thrown and kicked by a vicious horse, in such a manner as to have both his thighs greatly hurt, he boiled the Sarothra and applied it to his wounds. It not only immediately appeased his pain, which before had been very violent, but he likewise by its assistance recovered in a short time.
Having read in Mr. Miller’s Botanical Dictionary, that Mr. Peter Collinson had a particular Larch tree from America in his garden, I asked Mr. Bartram whether he was acquainted with it, he answered, that he had sent it himself to Mr. Collinson, that it only grew in the eastern parts of New Jersey, and that he had met with it in no other English plantation. It differs from the other species of Larch trees, its [[127]]cones being much less. I afterwards saw this tree in great plenty in Canada.