the stones which occur in drift, are water-worn and rounded; thus showing that they have been rolled along in some mighty current, till all their angles have worn away. We see hard quartz rocks, weighing many tons, that have been perfectly rounded and smoothed in this way, and can thence conjecture how fearful must have been the rush and the war of elements, that produced such effects.

Geologists consider that there have been several periods of drift, on the northern part of this continent; all of them being in a westerly direction, coming from the east. Some ascribe it to the action of ice, either in the form of glaciers, or icebergs; others to the upheaval of the bottom in some portion of the north sea, sending an indescribable torrent of mingled mud, ice, and water, sweeping over the face of the country; tearing away hills, scooping out valleys, crumbling away various strata of rock, and depositing their materials in different and often far distant localities.

The fact that the rocks on the sides of some of our highest hills, are ground smooth, and marked with scratches and even deep grooves, in the direction which these currents, or masses of ice, took, shows how irresistible must have been their force, and how great their volume.

In some cases, the action of this drift has been, to cover up good soils, or rocks that are capable of producing such soils, with immense accumulations of sand and gravel. In other places it has deposited a better class of substances than the original. On the whole, it may be considered that it has done good, by mixing the ruins of various formations; varying the soil, and the consequent productions, over districts that would otherwise have been uniform; and where the want of these various materials might have been severely felt, in all the ordinary occupations of life. What must have seemed at the time, wild chaotic confusion and ruin, was then after all, a wise provision of God, to prepare this continent more perfectly for our habitation.

There are other sections, where foreign accumulations cover the original soil, and alter its capabilities, from causes than we can more fully comprehend; causes which are operating at the present day. These are alluvial plains, formed by substances deposited during the annual overflow of rivers. These, during high water, become charged in the rapid currents of their sources, with materials from all of the formations through which their course lies. When the water reaches the plains of the low countries, where it has room to expand beyond its usual limits; a deposit of these suspended substances takes place, as soon as the current is checked by spreading out over the surface, and its flow becomes tranquil.

Thus an annual layer is formed, which in time makes a soil of great depth, and usually of great fertility; for the reason that it is a mixture from the ruins of many rocks, and therefore likely to contain all that plants need. We have many instances of such soils in this country; on the banks of the Connecticut, of the Mohawk, of the Mississippi, and a hundred other streams.

These causes then, are sufficient reasons for saying that we cannot always assert what any particular soil will be, if we know the rock of the district in which it is situated. Our opinion upon such a subject must be given with the reservation-" If there have been no disturbing influences." An inspection of a district by a practised eye, would immediately detect any foreign deposits, and determine their character.

It is easy to perceive how a knowledge of this subject, even of a superficial nature, must be valuable to a practical man. If his soil is formed by the decomposition of a granite rock, he can ascertain with little trouble, what are the constituents of that rock, and what are the special manures most likely to prove beneficial in his section. So also if he wishes to buy land in a distant region, and has no definite knowledge as to its character; he may determine its probable quality at once, from a good geological map. If he has cultivated the soil of some particular formation, till he has come to like it, and to know better how to cultivate it than any other; he may in the same manner learn where to find for himself, or for his children, the same kind of land in some other district.

I may observe in conclusion, that while Geology is thus practically useful, it also is among the most interesting of sciences; for it takes us back through ages that are past, and lays open the early history of our globe, with its silent yet speaking records of extinct races, and of sudden, overwhelming changes.

Nothing in this world can give such an idea of antiquity, as one of these fossils that I have mentioned; the remains of a fish, or a shell, from some of the lower stratified rocks. We are accustomed to think of the pyramids as ancient; but this creature enjoyed life, and fulfilled its part in the animated world, at a period which brings the pyramids, in comparison, down to things of yesterday. Since it died, race after race, in gradual progression, has occupied the seas and the land; has in its turn been sooner or later swept away, to make a part of some new formation. Wide seas or rapid torrents have rolled over its resting place; and then again by a new change, it has supported the immense growth of some old fossil forest on dry land, which, in its turn overwhelmed, gave place to other seas, containing still other forms of

life.

After all these unnumbered centuries of revolution, it comes forth to the gaze of man upon the earth, which in its day and generation it helped to prepare for his abode; to speak to him of the infinite power of that Being who made them both.

It is thus with everything in this world of ours: on every side we are reminded of a superior, and an All-wise Creator. We have been tracing nothing but the evidences of his wisdom and power, in the simple, yet beautiful laws which regulate the being and growth of all living things; and here we have in this bit of stone, an evidence strong as doubt itself could demand, that these same laws were in operation thousands of years before any of our race existed.

To study such laws, then, is a noble, as well as attractive pursuit, for they are not to outlast us, as they will everything in the material world around us, whose existence and whose periodical changes they regulate.

Our bodies, it is true, will come under the universal power of death; will be resolved once more into their various elements; will perform once more their part in that great circle of life, which we have endeavored to follow in its varied round; but our souls will be beyond all such influences; will, living, be acting out an immortal destiny, in a world where every transformation will not be a step toward ultimate decay, and where the blossoms of this brief lifetime will ripen into the sweet or bitter fruits of eternity.

CULTIVATION OF POTATOES AT MOUNT AIRY COLLEGE, PENN.

(Extract from Report of JOHN WILKINSON, Principal.

We have had a favorable season for our crops generally; though potatoes diminished at least 50 per cent. by the bug (sec article annexed, on the curculio) in the tops, which were killed before the crop was half matured. I noticed, when harvesting, that there was occasionally a hill, the tops of which were still green; and on examination found these were all of a variety produced on the place, which we call "purple seedlings," which were accidentally mixed with the Mercers, (our principal crop,) and found that they yielded at least one-fourth more than the Mercers, and did not appear to be affected by the curculio, and were large and fine, and perfectly sound. But on examining the tops, it was found that the insects were as abundant in these as in the Mercers; but, owing to their being so much larger than those of the Mercers, there was abundant room and nutriment in the center of the plant for the insect, without destroying or interfering with the circulatory portions of it. These have been preserved for seed.

For potatoes, we use long yard manure, spread on the surface just immediately before planting, which is raked into every other furrow in which the seed is placed, under the manure, and on the furrow side of the furrow, or under the edge of the furrow slice, and before they are plowed in; the manure over the potatoes is strewed with the pine coal and ashes obtained from the locomotive, burning pine wood. In case of an insufficiency of yard manure, we use guano, about 300 lbs. per acre, which we prepare thus: Screen the guano to separate the lumps, which are pulverized on the barn floor by means of the flail; then mix with fine coal, ashes and gypsum,-two parts guano, one of gypsum, and seven of coal; strew it on the seed in the furrow.

We experimented in planting one portion of our potatoes by strewing the seed in the furrow, with very light wheaten bran, about 100 bushels per acre, and the product was fully equal to any other portion of the field. We use potatoes, for seed, of medium size, cutting so as to insure two eyes to each piece, and place them eight inches apart in depth, and ten in width. When we have completed the planting, we roll thoroughly. About ten days after the planting, we cultivate the whole surface with the cultivator, and continue to use the harrow in the dry part of the day, nearly every day, until about half of them are up. If managed thus, they need but little more cultivation; the passage of the cultivator through them once will be sufficient. We raise them by plowing the same way that we plowed when planting, except that we turn the back into the dead furrows, running the cultivator, drawn by one horse, in the furrow from which the potatoes have been picked, which will uncover what the plow has not. After this process the ground is harrowed, cross-plowed, and the potatoes again picked, when it is sown with 300 lbs. of guano, (prepared as above described,) the wheat sown, and both cultivated in together.

TENTH FAMILY.

CETONIDAE.

(By Miss MARGARETTA H. MORRIS, Mount Airy, Germantown, Penn.)

The curculio trinotatus of Melsheimer-Baridius, Say-Baridius restitus, Schōnher, deposits its egg on the leaf buds of the potato vine, from eight to eighteen inches above the ground. The eggs, when first deposited, are bright red, but soon change to a pale yellow; they are deposited singly upon the bud, at the foot-stalk of the leaf, and never more than three on a stem. The young grub, which is of a pale yellow color, soon penetrates the bud, and enters the stem of the plant, where, with its head downwards, it feeds on the interior of the stem, and proceeds towards the root, where it frequently undergoes its change. When there are three in one stem, the whole interior of the stem, from the spot where the worms entered to the end of the root, will be found hollow. Here the insects undergo their entire change, and may be found in various states of progress, according to the season in which they are searched for; the perfect insect seldom leaving the stem until the plant is quite dead, from which I infer that the potato plant is the food of the perfect insect, as well as of the grub. The potato plants seldom show signs of injury until the grubs have arrived at maturity, unless the weather be hot and dry; then they soon wither, and the plants look as if they had been scalded. January 20th, 1850.

ANALYSIS OF THE APPLE.

(By J. H. SALISBURY, M. D.)

This examination was entered into with the view of throwing some light upon the composition of the apple. To determine whether or not, it contained a sufficient percentage of nutritious matter to render it profitable as food for stock. That it has been used with a good degree of success, in many instances, for several years, is well known; but it is by no means generally acceded, that the apple is as nutritious as it actually is. Those who have had some experience in feeding good varieties, will find in the following analysis the reason of their favorable opinion of this valuable product of the farmer;-valuable, because if properly managed, the crop is sure, large, rich, and attended with less labor and expense than almost any other.

It was the intention to have analyzed several varieties of sweet apples, but owing to the lateness of the season before the examination was commenced, and the scarcity of these varieties, I was unable to obtain any, except the Tolman Sweeting.

PERCENTAGE of water, DRY MATTER AND ASH, IN THE

The above results were obtained the first of March. The percentage of water in the six varieties examined ranges from 79.21 to 86.31 per cent. The Kilham Hill contains most, the Swaar stands next, the Greening third, and the English Russet has the least. The percentage mean from the six results is 82.664.