since they have been mostly extracted by mineralogists and collectors. Being disappointed on a former visit to this place in 1827, I thought that when the rocks had decomposed, we might find the beryls in the soil, and by digging into the earth, Mr. Alger and myself, aided by a laborer, succeeded in obtaining in a few hours no less than two bushels of crystals. I have not yet had time to make any further explorations, but doubt not that there still are an abundance of beautiful specimens in this town:

Very large crystals of beryl have recently been found in the town of Albany, between Bethel and Waterford. I have not yet visited the place, but have seen a specimen of large size, which was sent to Professor Cleaveland, in Bowdoin College.

Brunswick and its vicinity have been most faithfully searched for minerals by Profr. Cleaveland and his pupils and a great variety of interesting specimens have been found. The rocks of that town are chiefly gneiss, cut through by an infinity of large veins of coarse granite containing large masses of felspar, admirably adapted for porcelain making. The general direction of these veins coincides with those formerly noted. The falls of the Androscoggin rush over rough, craggy masses, of these rocks. Specimens of this felspar have been wrought into beautiful mineral teeth by the Boston dentists, who prefer it to any other for their purposes, since it melts easily, and is free from oxide of iron. Fine poppy-red garnets abound in this rock near the falls, but they are seldom large and perfect enough for jewelry. Sulphuret and the oxide of molybdena occur below the bridge, close to the water's edge, and can be obtained only when the river is low.

A beautiful variety of green mica slate, filled with crystals of iron pyrites, was discovered in Brunswick, by Prof Cleaveland many years ago, and elegant specimens of it may be seen in almost every cabinet in the country. Large and valuable beds. of pure crystalline white limestone, suitable either for marble or for lime, occur in the. S. E. part of Brunswick, near the coast on the estate of Mr. Jordan. The dimensions of these beds

were given in my Report for the past year, to which I beg to refer for their description.

TERTIARY FORMATION OF PORTLAND.

While digging the space for a cistern in King street, in Portland, a great number of marine shells were thrown out, some of which were preserved by Mr. Gordon, and submitted to my examination. They belong to the tertiary deposit, and are similar to those which I have formerly noticed, and are found 50 feet above the level of high-water mark. The shells are the nucula, mya, saxicava, &c; which are found in regular beds of clay, and were evidently in their natural positions, just where they had lived and died-the whole mass having been since elevated 50 feet above the sea.

SLIDE OF THE PRESUMPSCOT, WESTBROOK.

This locality is one of interest, on account of the vast number of fossil shells which are exposed to view on the surface of the clay, they being washed out abundantly by every fall of

rain.

This slide is said to have taken place during the night in the month of May, 1831. The season is said to have been uncommonly wet, and the clay probably loosened by the frosts of winter, was rendered slippery, so that when its hold was broken it glided forward into the river. The waters of this stream were stopped in their course, and so dammed up as to overflow their banks and alter the channel to the South Eastward. place is worthy the attention of the curious.

This

On examination, we find no less than 12 different winrows or long masses of clay, which have been precipitated forward, and the stumps of trees remaining, all point toward the river. One of the trees on the border of the stream, stands inclined at an angle of 40° from the perpendicular, and towards the stream. The space left by this slide, is 120 yards in diameter, and the clay-banks exposed, are elevated 30 feet from the river. The lower bed of clay was of a dark blue, and very tenacious and plastic, while the upper beds are more sandy, and of a light

grey color. Throughout the whole mass of the clay, we find an abundance of perfect marine shells frequently preserving the epidermis unaltered. Some of them are petrified, but more frequently they are unaltered. Among the shells obtained, are the following:-nucula portlandica, and new species of the same genus not yet described, two species of the mactra, mya dehiscens, saxicava, sanguinolaria, balani, and occasionally the remains of crabs and other crustacea. The various shells found at this slide are evidently of marine origin, and now we find them at an elevation of from 65 to 70 feet above the sea. It will be remarked that this elevation coincides nearly with the height of the tertiary deposits of Portland and Gardiner, and with the lower tertiary clay of Bangor.

At the brick-yard, near Pride's bridge, we found perfect casts of the natica and mytilus. This deposit is elevated about 60 feet above the sea, and belongs to the same formation as the clay at the Slide.

Before closing our remarks on the tertiary formation in Maine, let us observe, that the general height which these deposits attain, is about 70 or 80 feet, and since no such deposits occur at greater altitude than 100 feet, it is evident that the ancient tertiary sea covered the land only to that depth, and consequently a large portion of the State, now above its surface, must formerly have been submerged beneath the waters of the ocean, while the various prominences rising to a greater height than I have mentioned, must have stood like islands in the midst of the waves. A small portion of the land on which the cities of Portland and Bangor, are built, as well as a part of the land at Gardiner, Hallowell and Augusta, remained above the surface of the ancient ocean. These observations have not only a scientific interest, but a practical result, for the common brick-clays, being of this formation, generally lie below the altitude of 100 feet from the sea-level, and the higher land is destitute of such deposits. The plastic clay of Turner is of freshwater formation, and there occur also diluvial clays, but not abundantly. Hence in the elevated table lands of the State, we find that clay, suitable for brick, is comparatively

rare.

The influence of the ancient sea, in the formation of soils, is not to be overlooked, for some of the richest calcareous marls are tertiary deposits. The water percolating through clay containing many marine shells, is always impregnated with carbonate of lime, and this occurs in such quantities in some wells of Portland and Bangor, as to become very sensible to the taste. It is deposited when the water is boiled, forming a crust within the tea-kettle.

In New Jersey there occur very extensive beds of marine shells belonging to the tertiary formation which are sought for as a manure for soils, and according to the report of the geological surveyor of that State, the quantity of this kind of marl varies according to the nature of the shells that it contains, some undergoing more rapid disintegration than others, so as to cause them to act more rapidly upon the soil. So far as our researches in Maine have extended, we find the shells too sparsely mingled with the clay to produce marl.

By calling public attention to this subject, I hope that many observing persons will engage in a search for deposits of seashells and marl, which if found, will add greatly to the agricultural interests of the State. Whoever remembers the formerly barren lands of New Jersey, now rendered fertile by this substance, discovered by her geologists, will appreciate the value of such a discovery. I would also beg leave to call the attention of citizens of Maine, to the recent marl formed by the decomposition of fresh water shells, on the shores of the lakes and rivers, for where many such shells are heaped up on the shores, they form marl.

In Pittsfield and Lenox, Massachusetts, marls evidently owe their origin to the decomposition of an infinity of fresh water shells, such as the planorbis, cyclas, and lymnea, and according to my analyses, they contain from 70 to 80 per cent. of carbonate of lime, besides a considerable quantity of vegetable matter.

Marls of a similar character occur on the shores of Millinocket lake, and may be seen at the carrying place between that and the Ambejegis lake, where the expansion of freezing water has turned up the muddy bottom.

GRANITE.

This rock is essentially composed of the three minerals, quartz, felspar, and mica, crystalized or aggregated together, without any cement. Its good qualities as a building-stone, depend upon the regularity and admixture of these minerals, and upon the absence of those substances that deface or decompose the rock. It exhibits an infinite number of varieties of color and texture, while there are a few substances that have a chemical action upon it.

In some granites, the felspar is exceedingly hard, and breaks with an almost glassy fracture, presenting sharp and well defined edges, while it is translucent or transparent. This is the strongest kind of felspar, and it endures the action of the weather longer than the dull, earthy varieties. The mica contained in granite is of various colors, such as white, silvery-grey, green, red, or black; hence, from the intermixture of variable proportions of this mineral, we have the different shades of color. The quartz is an unalterable ingredient, and falls out when the other minerals have decomposed.

It will be generally observed, that black mica decomposes more rapidly than the lighter colors, while the bright white or silvery mica is slow in decomposition. The felspar, as it decomposes, first turns white, if pure, while if it contains protoxide of iron, it turns yellowish brown, and is gradually removed by rain and running water, and deposited on the lower lands in the state of clay. The quartz remains in sharp particles, or is worn by attrition into siliceous sand.

Sienite is composed of the same minerals as granite, excepting that it contains hornblende crystals instead of mica. The felspar of sienite is, however, more frequently impure, from the presence of prot-oxide of iron, and a little manganese;