stances, with which they are said to be accompanied, seems to indicate their recent origin. It is certain at least from Beudant's account, that they were not anterior to the ter tiary class of rocks, for they are seen in several places resting on the molasse.

Volcanic Rocks of Transylvania.

In Transylvania,* volcanic rocks of undoubted tertiary origin occur in the eastern part of the country alone.

The above formation constitutes a range of hills covered with thick wood, which separates from Transylvania the Szeckler land, or the valley in which the Hungarian tribe of that name reside.

The chain itself extends from the high hills of Kelemany, north of Remebyel, to the hill of Budoshegy, about ten or twelve miles north of Vascharhely. The wild tract included within this mountainous range is so broad, that it requires a day's journey to cross it in a carriage; at its northern extremity, however, it gets gradually narrower. Its limits are, to the east the river Marosch from Toplitza upwards, the Aluta from Varosch to Tuschnad and Kasson; to the

* I am indebted for the whole of this account of Transylvania to my friend Dr. Boue, the author of a Geognostical Essay on Scotland, and of several interesting papers on the Geology of France and Germany. Its value is enhanced from the circumstance that no individnal, so far as I am aware, has communicated to the public any description of this remote country, since the branch of natural history which relates to the physical structure of the earth has began to assume its present form. It is to be regretted that Dr. Bouè did not complete his undertaking, which comprehended the whole of the Bannat, and the provinces of the Austrian empire, as far as Trieste, but a severe illness, occasioned by the villainy of a servant, who attempted to poison him, in order the more readily to make off with his money and property, brought his researches to an abrupt termination. Before however this event occurred, he had examined a great part of the southern and eastern portion of Hungary, including the trachytic formation of Transylvania, of which he has sent me the subjoined account.

west, a line passing through Kasson, Tulle, Udyarhely, Parayd, Libonfalva, and Pata. It is for the most part composed of various kinds of trachytic conglomerate; of which the best sections are presented along the course of the Marosch, for elsewhere a most impracticable forest of pine and oaks covers it nearly throughout. From the midst of these vast tufaceous deposits, the tops of the hills composed of trachyte, a rock which forms all the loftiest eminences, here and there emerge. Of these the most elevated is called Kelemany; the other principal ones are Fatatschion, Pritzilasso, Hargala, Barot, the hills south of Tuschnad, &c. &c. The trachyte is ordinarily reddish, greyish, or blackish; it mostly contains mica. In the southern parts, as near Tschik Sereda, the trachyte incloses large masses, sometimes forming even small hillocks, of that variety of which millstones are made, having quartz crystals disseminated through it, and in general indurated by siliceous matter in so fine a state of division that the parts are nearly invisible. The latter substance seems to be the result of a kind of sublimation, which took place at the moment of the formation of the trachyte.

Basalts were no where observed, although black trachyte abounds. Distinct craters are only seen at the southern extremity of the chain. One of the finest observed by Dr. Boue was to the south of Tuschnad; it was of great size, and well characterized, surrounded by pretty steep and lofty hills composed of trachyte. The bottom of the hollow was full of water. The ground near has a very strong sulphureous odour. A mile in a S. S. E. direction from this point there are on the table land two large and distinct "maars,' like those of the Eyfel, that is to say, old craters, which have been lakes, and are now covered with a thick coat of marsh plants; the cattle dare not graze upon them for fear of sinking in.

Some miles farther in the same direction is the wellknown hill of Budoshegy (or hill of bad smell), a trachytic mountain, near the summit of which is a distinct

rent, from which exhale very hot sulphureous vapours. The heat of the ground is such as to burn the shoes. A deposition of sulphur has taken place there, and the rock is converted into alum-stone by the action of the vapors upon the constituents of the trachyte. In this manner hollows are formed in the rock. At the base of the hill are some very fine ferruginous sulphur springs, much resorted to for various diseases by the inhabitants, who encamp near them in the open air during summer. Chalybeate sulphur springs generally abound at the base of this volcanic range, and chalybeates with carbonic acid still more. Some of these appeared as good as those of Pyrmont, and the most famous, that of Borsah, a bathing place much resorted to by the Transylvanian nobles, contains more carbonic acid than Pyrmont water itself.

The craters last described have thrown out a vast quantity of pumice, which now forms a deposit of greater or less thickness along the Aluta and the Marosch from Tuschnad to Toplitza. Impressions of plants and some siliceous wood are likewise to be found in it, as is the case in Hungary. These fragments of pumice have been deposited under water. Some, says Dr. Bouè, might be disposed to set down a more considerable portion of Transylvania as trachytic, than I have done, but I have satisfied myself that many rocks which may appear to be trachyte are nothing but some of the newer transition or coal-sandstone porphyries, which are here and there more scorified than elsewhere, or of which the scorified portions have stood the action of the weather better than the rest. This may be the case with the most recent porphyries of the two great deposits of that formation, the one of Marmorosch, the other in the Gespannschaft (comitat) of Hunyad, and the Stuhl of Muhlenbach. On these I shall dwell at full length in my general account of Transylvania.

To this account of the volcanic rocks of Transylvania, I have only to add that a basaltic cone is mentioned by Beudant as occurring in Schlavonia near Peterwaradin, and that I

have myself seen specimens from that province, and probably from the same locality, in the possession of Professor Schuster at Buda, which from their scoriform aspect I should judge to be of modern formation.

Dr. Bouè also informs me, that between Ober-Pullendorf and Stoop, near Güns in Hungary, south of the lake of Neusiedel, is a flat conical hill about 100 feet in height, half a league in its greatest diameter, and a quarter of a league in its smallest, which rises from the midst of the upper tertiary deposits, or amongst the marly beds lying above the blue shelly marl common to Austria and the Apennines. The rock itself is composed of a blackish or greyish felspathic basalt, which is sometimes compact, and contains oval nodules, partly of mamillary or botryoidal iron ore, and partly of arragonite; sometimes very porous, and with the cavities either entirely empty, are coated with globules of sphæro-siderite.

The direction of the cells is from east-north-east to westsouth-west, and the same is the direction of the range itself. It is decidedly a tertiary basaltic cone, having its base only covered by recent marls.

On the Volcanic Rocks of Styria.

On my way from Vienna to Italy I deviated a little from the direct road, in order to look at some rocks of a volcanic nature that occur near Friedau in Styria, a little to the south-east of Gräbz, of which the only account which has been published, is one by Von Buch, in the Transactions of the Academy of Berlin.*

The formation in question may be briefly stated, as consisting of a central nucleus of trachyte, which consitutes the lofty conical hill called the Gleichenburg, round which on all sides are mantle-shaped strata of volcanic tuff, alternating with beds belonging apparently to the tertiary class.

* Vide Leop. von Buch in der Abh. der physical Classe der Kön. Akademie zu Berlin, 1818.

This tuff consists in general of a congeries of very minute fragments of volcanic matter, which seem to have been immediately ejected from the volcano, mixed up and loosely agglutinated with small quartzy pebbles. In the midst of it are fragments of cellular and compact basaltic lava, sometimes containing nests of olivine. Masses of the same substance of a globular form, not imbedded in any matrix, are found also distributed amongst the tuff. Specimens of augite, and of a substance looking like altered granite like-wise occur. The tuff becoming more and more mixed with particles of clay and sand, passes at length into a loamy earth, at first dark, and afterwards, where it is unmixed with volcanic matter, of an ash-grey colour, The constituents are in a state of very fine divison, and a number of minute specks of silvery mica impart a sparkling lustre to the general mass.

Besides this, which looks like a bed of silt deposited tranquilly at the bottom of a lake, we find, at a somewhat greater distance from the central trachyte, strata of limestone, full of shells, belonging to the recent order of deposits, and especially abounding in that minute fossil, the miliolite, which imparts to the stone an oolitic appearance. At a village called Khelig, a little to the south of the former locality, I observed that the tuff, which here contained decided scoriæ, was superimposed on a rock which no wise differed from ordinary basalt, but in the existence of minute internal pores. It formed a number of concentric lamellar concretions, of which the external have become decomposed, whilst the internal retain their solidity. The exterior surface of the balls is coated with asphaltum. The whole rests upon a bed of marl without any traces of volcanic

matter.

Two hypotheses present themselves with respect to the age of the trachyte of the Gleichenburg; for it may either be said, that having been first thrown up by volcanic action, the beds of tuff and of marl collected by degrees around its base; or that after the latter had been formed in a position