This species I have named Larderellite, after Sr. Larderell.* On boiling the Larderellite in water, ammonia is given out, and a new crystalline salt is obtained, having the formula N HO4 B6 +9H. Berzelius obtained by neutralizing boracic acid and ammonia, a salt crystallizing in hexagonal prisms containing according to Gmelin N HO4 B4 +6й. It differs from the Larderellite in composition and strikingly in crystalline form. It appears that one and the same salt may be obtained, with different proportions of water, by employing different temperatures; and thus is easily explained the analogy between the borate of soda of the lagoons and borax, the borate of lime and hydroborocalcite, the Larderellite and Berzelius's borate of ammonia. In the same way. according to Berzelius, the sulphate of the protoxyd of manganese crystallized at the temperature of 6° R., gives the formula Mn S+7H, but between 6° and 20°, the formula Mn 3+6й; and between 20° and and 30°, Mn S+4. The interesting point in this subject is that these compounds of manganese differ widely and irreconcilably in crystallisation, showing the influence of the water of crystallisation on the crystalline form.

Laurent takes boracic acid for monobasic-as the borate of oxyd of methyl C2H30, BO3 + HO, BO3; and the borate of oxyd of æthyl =C4H5O, BO3 + HO, BO3; and borax for a neutral salt, in which 1 equivalent of base is replaced by 1 of water, whence the formula of borax is

Na O, HO, 2BO3 +9HO or 2((Ña, H) Ë) + 9Ĥ.

This view is sustained by many examples among other boracic acid compounds, which are described in Wöhler and Liebig's Annalen. Following Laurent's theory my formulas become, for the

[The author closes with some observations on the condition of the boracic acid of the lagoons.]

3. On the Thickness of the Ice of the Ancient Glaciers of North Wales, and other Points bearing on the Glaciation of the Country; by Prof. RAMSAY, (Proc. Brit. Assoc., Athen., No. 1405.)-Prof. Ramsay stated his belief that there had been two sets of glaciers in North Wales since the ground assumed its present general form. The first was on a very large scale, followed by a slow subsidence of the whole country to the extent of 2,300 feet, until only the tops of the highest hills remained uncovered by the sea; and when the mountains again rose, a set of smaller glaciers was formed. The thickness of the ice in existing Swiss glaciers was known to be very great; in the Grindelwald it had been ascertained to amount to 700 feet, and in other instances was probably thicker. The observations of Agassiz and Prof. James Forbes on the height to which grooved and polished surfaces span up the sides of Alpine valleys, had led to the conclusion, that the ice had once been much more extensive; and that in the glacier of the Aar, for example, it must have amounted to 2,000 feet. The same * Another hydrous compound of boracic acid and ammonia I have since noticed which will hereafter be described.

SECOND SERIES, Vol. XIX, No. 55-Jan. 1855.

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method of observation had been applied to North Wales; and it had been ascertained that in the Pass of Llanberris the grooves and roundings of the rocks extended to a height of 1,300 feet above the present bottom of the valley. The drifted deposits which overlie these rounded surfaces must have formed during the slow depression which followed, and the glaciers must still have existed, since these deposits, though marine, are still of a moraine character. The cold climate continued during the period of depression, and for some time after it; and there was beautiful evidence in the side valleys of the gradual decrease of the glaciers until they died away amongst the higher mountains, in the form of moraines stretching across the valleys, one within the other. The scratches made by the first set of glaciers passed down the valleys; those of the smaller glaciers crossed the first obliquely.

:

4. On the Foliation of some Metamorphic Rocks in Scotland; by Prof. E. FORBES, (Ibid.)-It was of great importance to geologists to distinguish between lamination, cleavage, and foliation: the first resulted from original planes of deposition the second was a superinduced structure, dividing rocks into laminæ of similar constitution, not coincident with the lines of bedding; thirdly, foliation was the division of a rock into laminæ of different mineral condition. Cleavage had been attributed, by Prof. Sedgwick, its first definer, to electrical action; by Mr. Sorby, to a mechanical force; and by Mr. D. Sharpe, to mechanical and chemical influence. The foliation of mica slate, or separation of its mineral constituents into distinct layers, had been sometimes attributed to metamorphic action on layers of different constitution; Mr. Darwin had considered it identical with cleavage, and due to the same cause, the one passing into the other: the same view has been maintained by Mr. Sharpe. Prof. Forbes agreed with those who considered it a superinduced structure quite distinct from cleavage or lamination. The author then referred to examples of foliated structure. In a roadside quarry at Crianlarich, near the head of Loch Lomond, where the metamorphic limestone is not distorted, and exhibits distinct lines of bedding, of a pale blue color, caused by the presence of iron; also lines of different mineral matter, the lamina frequently curved round nuclei; and dark lines of crystals of calcareous spar, produced, perhaps, by the metamorphism of bands of fossils. In the upper part of the quarry the limestone becomes foliated with mica,-the foliation being at first parallel with the bedding, then becomes wavy and contorted, is affected by small faults, and contains nuclei of calcareous spar and at length passes into a mica slate. At Ben Os there is a calciferous band in the mica slate, which, having the same strike with the Crianlarich beds, may eventu ally prove a guide in unravelling the structure of the country. Two miles from Inverarnon there is a bed of porphyritic trap in mica slate, and the foliation on the sides of the trap is conformable. Four miles from Inverarnon, in a quarry of trap, which sends large and small veins into the mica slate, there is evidence of a second foliation having taken place, following the small veins of trap. Near Tarbert, the mica slate is foliated and contorted; and a bed of calcareous grit cuts through it, without disturbing the relations of the curves and laminæ. In a slate quarry at Luss, the foliation accords in the main with cleavage, as observed by Mr. Sharpe, in the corresponding district; but whilst the foliation curves round the nuclei of quartz, the cleavage abuts against them.

Foliation has also been noticed in the baked rocks of Salisbury Crags. Prof. Forbes concluded, 1, that foliation was a superinduced structure; 2, that it was distinct from cleavage; 3, that it was not of mechanical origin, but a chemical phenomenon; 4, that it was, perhaps, induced by more than one agency.

5. On the Relations of the "New Red Sandstone" of the Connecticut Valley and the Coal-bearing rocks of Eastern Virginia and North Carolina; by Prof. W. B. ROGERS, (Proc. Boston Soc. Nat. Hist., 1854, p. 14.)-Prof. W. B. Rogers exhibited a series of fossils from the middle secondary belts of North Carolina, Virginia, Pennsylvania, and Massachusetts; chiefly, he said, with the view of calling attention to the evidence afforded by some of them, of the close relation in geological age between what has been called the New Red Sandstone of the Middle States and Connecticut Valley, first designated by Prof. H. D. Rogers as the Middle Secondary Group, and the coal-bearing rocks of Eastern Virginia and North Carolina.

Prof. Rogers referred to the existence in Virginia of three distinct belts of these rocks. The most eastern of these, extending almost continuously from the Appomatox River to the Potomac, includes the coalfields of Chesterfield and Henrico Counties. The middle tract, about twenty-five miles west by south of the preceding, is of much less extent, and has not yet furnished any workable coal seam. Somewhat intermediate in trend to these is a belt of analogous rocks in North Carolina, commencing some distance south of the Virginia line and stretching southwestwardly across the State, and for a few miles beyond its limits, into South Carolina. This area, first mapped by Prof. Mitchell, includes the coal-bearing rocks of Deep River. The western belt extends, with two considerable interruptions, entirely across Virginia, being prolonged towards the southwest in the course of the Dan River in North Carolina, and towards the northeast through Maryland, Pennsylvania, and New Jersey, forming what is usually called the New Red Sandstone Belt.

Eastern and Middle Belt of Virginia and Eastern Belt of North Carolina. From an examination some twelve years ago of the fossil plants of the most eastern of the Virginia belts here designated, Prof. Rogers had been led to refer this group of rocks to the Oölite series on or near the horizon of the carbonaceous deposits of Whitby and Scarborough in Yorkshire. Some years later he discovered many of the same plants in the middle belt of Virginia, and, in the summer of 1850, he found several of these plants in the coal rocks of Deep River, in North Carolina. In each of the latter districts we meet with Equisetum columnare, Zamites, and a plumose plant referred to Lycopodites, and strongly resembling L. Williamsonis of the Yorkshire rocks. These are among the usual forms occurring in the easternmost of the Virginia belts.

Besides the fossil plants common to these three areas, they contain two species of Posidonomya and two of Cypris. Of the Cypridæ, one species has a smooth, the other a beautifully granulated carapace. They are both very small, seldom exceeding an inch in length and in width. Both species of Posidonomya differ in proportion from

the P. minuta of the European Trias, but one of them strongly resembles the P. Bronnii of the Lias, although of larger dimensions.

Prof. Rogers remarked upon the uncertainty which exists as to the true nature of the small shell-like fossils, which being assumed as molluscs, have been referred to Bronn's genus Posidonomya. But, whatever may be their zoological affinities, the fossils now under consideration have great interest, as affording further means not only of comparing together the mesozoic belts of North Carolina and Virginia, above referred to, but of approximating more justly than heretofore to the age of the so-called New Red Sandstone, or Triassic rocks which form the prolonged belt lying further towards the west.

In the report of Prof. Emmons, published in the autumn of 1852, mention is made of the remains of Saurians in the Deep River deposits, as well as of the Posidonia and Cypris, and of an Equisetites, a Lycopodites and other allied forms, together with a naked, rather spinous vegetable, regarded by him as a cellular cryptogamous plant.

In view of the general identity of the fossils thus far found in the Dry River and Middle Virginia belts, with those of the most eastern deposit in Virginia, viz., that including the coal of Chesterfield, Prof. Rogers maintained that the general equivalency of these three areas may be regarded as established, and therefore the Dry River belt of North Carolina, as well as the Middle Virginia belt, ought to be placed in the Jurasic series, not far probably above its base.

Western Belt of North Carolina and Virginia and its Extension towards the Northeast, forming the so-called New Red Sandstone of Virginia, Pennsylvania and New Jersey, and probably of the Valley of the Connecticut.-In North Carolina, on the Dan River, where the rocks include one or more thin seams of coal, the same Cypridæ or Posidoniæ are found in great numbers in some of the fine-grained shales and black fossil slates. The latter were noticed as early as 1839, by Dr. G. W. Boyd, while on the Virginia Geological Survey. Regarding this fossil, of which specimens were also obtained about the same time 'from the middle belt in Virginia, as identical with the Posidonia of the Keuper, Prof. Rogers had, many years ago, announced the probability that a part or all of the great western belt was of the age of the Trias, instead of being lower in the Mesozoic series.

Specimens of the Posidoniæ and Cypridæ, from both belts in North Carolina, and from the eastern and middle belts in Virginia, were exhibited by Prof. Rogers at the Albany meeting of the American Association of Science, in 1851, for the purpose of showing the close relationship between these deposits, in geological time. Among the speci mens from the Dan River, Prof. Rogers on the present occasion referred to the impression of a Zamite leaf and a joint of Equisetum columnare. Prof. Emmons, in the report above referred to, speaking of the marly slate of this system, says that "it differs in no respect from that of Deep River, bearing the same fossils, Posidonia and Cypris, in great abundance."

In the belt in Virginia, toward the Potomac river, Prof. Rogers had lately found immense numbers of the same Posidonia and Cypridæ, crowded together in fine argillaceous shales, and at several points he had met, in the more sandy rocks, vegetable impressions, which, although obscure, are strongly suggestive of the leaves of Zamites.

In the same belt in Pennsylvania, in the vicinity of Phoenixville, early last spring, Prof. H. D. Rogers discovered Posidoniæ in great numbers in a fissile black slate, and on subsequent examination, the same beds were found to contain layers crowded with the casts of Cyprida. Along with these are multitudes of Coprolites, apparently Saurian, resembling in size and form the Coprolites found in the carbonaceous beds on Deep River, and also some imperfect impressions of Zamites leaves. These facts Prof. Rogers considers sufficient to iden tify, as one formation, the disconnected tracts of this belt in North Carolina and Virginia, and the great, prolonged area of the so-called New Red Sandstone of Maryland, Pennsylvania, and New Jersey.

As to the geological date of this belt, Prof. Rogers said that the discovery at various and remote points of its course of Posidoniæ, Cypridæ, and Zamites, most or all of which are identical with these forms in the eastern middle secondary areas of Virginia and North Carolina, makes it extremely probable that these rocks, formerly referred to the New Red Sandstone, and of late more specially to the Trias, are of Jurassic date, and but little anterior to that of the Coal Rocks of Eastern Virginia.

Prof. Rogers considered the frequent occurrence of Cypridæ in all these belts as a strong evidence of their Jurassic age. While only a

few species of Cypridæ, and many of the allied genus Cytherina occur in the Silurian and Carboniferous rocks, there is a total absence of these crustacean remains throughout the series of deposits extending from the base of the Permian to the lower limits of the Oölite. But on entering the latter, the Cypridæ re-appear, and become very abundant there, there being no less than twelve species known to belong to the Oolite formations of Europe.

On comparing the silicified wood, found in the western and eastern belts, Prof. Rogers had found its structure to be, the same, and to agree very nearly with the fossils figured by Witham under the name of Peuce Huttonia. As this particular structure does not appear to have been met with below the Lias, and occurs in that formation, it furnishes another argument in favor of the Jurassic age of all these rocks.

Prof. Rogers added, that he had not found in the New Red Sandstone of the Connecticut Valley either the Posidonia or Cypris, although he had met with obscure markings which he was inclined to refer to the latter. He had however satisfied himself that one of the plants, from the vicinity of Greenfield, in Massachusetts, was identical with the form in the Virginia coal rocks referred to Lycopodites, and probably L. Williamsonis; and that among the other very imperfect impressions associated with this, was one which he regarded as the leaf of a Zamites.

On the whole, therefore, Prof. Rogers concluded that the additional fossils from the coal-bearing rocks of Virginia and North Carolina served to confirm the conclusion of their being of Jurassic date, and that the fossils, thus far found in the more western belt, and its extension through Pennsylvania and New Jersey, rendered it proper to remove it from the Trias and place it also in the Jurassic period, a little lower probably than the eastern belt of North Carolina and Virginia; and there could be little doubt, he thought, that the same conclusion would apply to the New Red Sandstone of the Connecticut Valley.