former papers for the fourth number, BERNARDINUS TELESIUS being studied, both from a general point of view as also specially for the sake of colour. SEEBECK's lecture on the unequal excitement of warmth in the prismatic sun-image was highly welcome, and my former ideas on those remarkable appearances again revived.

KÖRNER, the court mechanician, busied himself with the preparation of flint-glass, and, according to French prescriptions, set up in his workshop an instrument for the so-called polarisation experiments. The result, as we had long been instructed to expect, was pitiful, and it was remarkable enough that just at this time a feud between BIOT and ARAGO began to transpire, which to experts showed still more conspicuously than ever the nullity of the whole of this doctrine.

Herr VON HENNING visited me from Berlin. In consequence of my conversations with him, he became completely initiated into the theory of colours, and showed the courage to adopt it publicly. I communicated to him the table which should show to him what kind of phenomena in a chromatic exposition are to be observed and considered, and in what order.

In the knowledge of the surface of our globe we were much furthered by COUNT STERNBERG'S Flora der Vorwelt' in the first and second number. To this was added the Knowledge of Plants,' by RHODE, in Breslau. The primeval ox, brought from the Hassleber peat-pits to Jena, well deserves mention here, as one of the latest evidences of the earlier animal forms. The Archives of the Primitive World' had already come on a thought of this kind, and I had the particular pleasure on this occasion of renewing in Halberstadt my former friendly relation to HERR KÖRTE.

KEFERSTEIN'S intention of publishing a geological atlas for Germany met my most earnest wishes; I took a zealous part in the matter, and as far as the colouring was concerned, was ready with my advice and my views. Unhappily, on account of the indifference of the technical artists appointed to execute the work, this principal feature was not quite successful. If colour is to serve the map at all in the way of exhibiting essential dis

tinctions, it is necessary that the greatest attention should be given to it.

The Marienbad rocks were collected with care. Arranged in Jena, they were then communicated to the public by way of experiment, to meet a repeated request for them, as also to furnish successors in this field of labour with such a valuable provision. SARTORIUS deposited in the Jena museum a series of rocks coming from the Rhone, in confirmation of the views of his treatise on the volcano.

In this year, too, not despairing of ultimate success, I diverted the attention of my Silesian friends to the Prieborn organised sandstone, or by whatever name this wonderful species of rock may be called, as also to the vitreous tubes at Massel, in former times abundant but unknown.

In the most general way I received furtherance from D'AUBUISSON DE VOISIN'S 'Geognosy' and from SORRIOT'S map of the heights of Europe.

Meteorology was diligently prosecuted. Professor POSSELT did his part; Conductor SCHRÖN cultivated his talent ever more completely; Court-Mechanician KÖRNER was ready with his most careful aid in all technical preparations, and everything contributed to advance to the utmost possible degree the intentions and arrangements of the Prince. A manual of instruction was prepared for the whole body of observers in the grand-duchy, new tables being drawn and engraved. The atmospheric observations in the middle of April were remarkable, as also the height of smoke on the 27th of June. The young PRELLER made a neat copy of my cloud drawings, and that we might miss no kind of observations, the tower-warden in Jena was instructed to take notes of certain meteors. Meanwhile DITTMAR'S prophecies gave people much to talk about, but neither profit nor applause was reaped by them.

To give a tolerably complete account of the activity at Belvidere in the culture of plants would require a whole paper to itself. We shall only mention the erection of a palm-house, at once satisfactory to the man of science and gratifying to the taste of every visitor. The opposite end to that of the tropical vegetation was furnished with dried

specimens of plants from the island of Melville-specimens, however, which by their particularly sickly and wasting appearance only showed us the last traces of an otherwise well-known species of plants. The log of the trunk of a tree which had been injured, but had again coalesced, gave rise to many investigations into the recuperative powers of nature.

In Jena the botanical garden began to flourish with fresh life. Hofrath VOIGT, head-superintendent of the garden, and BAUMANN, the art-gardener, made a journey to Berlin, bringing home with them much that was profitable both for themselves and the establishment.

I held it expedient to close the two volumes of 'Natural Science and Morphology' with the fourth number, reserving so much material as would suffice for the preparation of a subsequent volume.

1822

Two important works conducted me to the old German architecture, to examination of its character through appreciation of its sentiment, and to a comprehension of the time in which it originated. MÖLLER'S 'German Architectural Monuments,' the first number of which was now completed, lay displayed to our view. After several proof-prints appeared the first number of BOISSERÉE's work on the Cathedral. A great part of the text which I had formerly studied in manuscript was appended, and now on my perusal of the whole it became clear as sunlight, as indubitable as the most palpable fact, that the religion, the morals, the peculiar phase of art, the peculiar spiritual needs, the physical and mental structure of the centuries in which this peculiar style of architecture bloomed forth so exuberantly-that these are never detached features, but only compose one great living unity. From this point of view it was to be explained how chivalry allied itself with ecclesiasticism, pursuing a different aim, yet animated with a kindred spirit.

Plastic art produced not many, but yet important fruits. The smaller medal with his Serene Highness's image and

the inscription Doctarum frontium proemia, was cut in Paris by BARRE. A little Bacchus in bronze, a genuine antique and of the greatest elegance, became mine through the kindness of Herr Major VON STAFF. On the Italian campaign he had made his way through Italy to Calabria, and had the opportunity of procuring many a pretty work of art. Knowing my predilection in this direction, he honoured me with the little image which never fails to enliven me as often as I look at it.

TISCHBEIN, out of old friendly affection, surprised me by a gem with stork and fox; the execution rough, thought and composition, however, quite excellent.

I receive The Climate of England' by HoOWARD, two volumes. PoOSSELT writes a review. Inland observations under all the different headings continue, and are regularly transferred into tables. Inspector BISCHOFF of Dürrenberg urges the value of comparative barometrical observations, a proposal which is favourably received. Drawings of cloud-forms were collected and attentively prosecuted. Observation and reflection go hand in hand, thereby by means of tabular representation the uniform course of so many, not to say all, barometers whose readings naturally stood parallel, suggests the finding of a telluric cause and the ascription of the rising and falling of the quicksilver, within certain limits, to the earth's constantly changing power of attraction.

During my stay in Bohemia this time, the geological collection of the Marienbad district was again taken in hand, and completed in relation to the documents and the list in press. The specimens, carefully arranged in a case, were at my departure given over to Dr. HEIDLER as basis for future investigation in natural science. The Tepler Museum honours me with beautiful lime-slate with fishes and plants from the Walsch estate. Agreeable and instructive conversation with Herr VON BUCH in passing. In Eger I met Herr Councillor GRÜNER, a diligent student of nature, engaged in raising a primitive colossal oak which had been lying deep sunk across the bed of the river. The rind was completely of the nature of peat. We next visited the quondam chalk pit of Dölitz, whence was derived the Mammoth's tooth which had been long

preserved as a remarkable heirloom by the family owning it, and was now intended for the Prague museum. I had a cast of it taken to show it for closer examination to Herr d'Alton.

With strangers, also, passing through the place the collection was contemplated and the problematic Kammerberg again visited. In the course of all this, Dlask's Natural History of Bohemia' was of furtherance and assistance.

Herr VON ESCHWEGE, who had come from Brazil, shows us jewels, metals, and stones. His Serene Highness makes a considerable purchase. On this occasion is made over to me the collection of precious stones formerly purchased from Brückmann's legacy. It was highly interesting to me to revise a series which had been gathered and arranged by a passionate amateur and connoisseur trustworthy and circumspect for his time, to intercalate later acquisitions and give to the whole as good an appearance as possible. Fifty unpolished diamond crystals, remarkable when looked at separately, still more so when viewed in a series, which were now described and arranged according to their structure by Herr SORET, gave me a perfectly new insight into this striking and highest product of nature. Herr von Eschwege further showed us the Brazilian species of rocks which again demonstrated that the rocks of the New World in their first original appearance completely accord with those of the Old; a fact on which both his printed and manuscript observations throw laudable light.

As a contribution to the knowledge of plants, I wrote the 'Plan to the Culture of Plants in the Grand Duchy of Weimar.' I obtained a clump of beechwood, admirably drawn, as a pathological phenomenon. It was a split log from a beech trunk, in which, several years before, the rind had been regularly marked with a cross cut into it, which, however, healing to a scar and overgrown, became incorporated into the trunk, the form and impression of the cutting being still distinctly traceable in the log.

My relation to ERNST MEYER imparted to me new life and stimulus. The species Juncus which he has more particularly defined and elaborated, I brought, with the