The preceding observations suggest to us the advantage that would be likely to accrue, by having the pendulum constructed without wood, on account of its being more susceptible of moisture than the metals.

ART. XVIII.-Notice of Scientific Travellers in Brazil,Prince Moritz of Nassau, George Margrave, Von Eschwege, and Prince Maximilian of Wied-Neuwied.

JOHN Earl Moritz, afterwards Prince of Nassau, was sent by the Dutch Government, in the year 1636, to Rio Janeiro with á military force, to protect the Batavian settlements in Brazil against the Spaniards. He was accompanied by several learned men, of whom the most distinguished were the astronomer George Margrave, a German, and William Piso, a Dutch physician. During a residence of eight years in Brazil, the Prince was actively engaged in collecting objects of natural history from all parts of that vast country. Intelligent men were sent out in every direction, in order to collect animals and plants, also to study the nature of the climate, and of the different productions of nature. This inquisitive and active commander even employed part of his suite in examining the opposite coast of Africa. Margrave, who was ordered on this service, fell a sacrifice to the climate of that country, at Paolo de Loanda, in the year 1644, at the early age of thirty-four. The Prince, on his return to Europe, brought with him the most extensive and valuable collection of the natural history of the New World ever seen in Europe. It was so great, that it not only completely filled the cabinet of the Prince, and the museums of two universities, but afforded abundant and rich supplies to various private collections.

Margrave, the most active of all the Prince's attendants, left behind him an extensive series of papers on astronomical subjects, which appear, however, to have been lost. His observations on the natural history of Brazil, which were numerous and important, had a more fortunate fate. They were pre

served, and the Prince delivered the whole to Piso, with an order to prepare them for publication. But Piso, occupied with other concerns, consigned these valuable documents to Dr J. de Laet, who had also accompanied the Prince to Brazil. Laet found great difficulty in decyphering the manuscript, so that frequently inaccurate explanations of passages were given. To increase the evil, the wooden cuts made from the drawings were, from the carelessness of the editor and the stupidity of the printer, inserted in wrong places; so that the descriptions and figures were often at variance. In this imperfect state the work appeared in the year 1648, in one volume folio, under the title Historia Naturalis Brazilia. The first part contains four medical dissertations by Piso; the second part contains Margrave's natural history of Brazil, which is in eight books: the three first treat of plants, four of animals, and the eighth of the country and its inhabitants. In the year 1650, Earl Moritz entered into the service of the great Elector of Brandenburg, by whom he was raised to the rank of Prince in the year 1654. The friendship of these illustrious men continued without interruption untill the death of Moritz in 1679. Some time before his death, he presented to the Elector all the drawings he had made and caused to be executed of the objects of natural history found in Brazil. The drawings were partly in oil, partly in water colours. Those in oil were the most numerous and valuable. The oil paintings were arranged in four folio volumes, and named according to Margrave. The first volume consisted of drawings of fishes, crabs, molluscæ, vermes, &c.; the second of birds; the third of mammiferous animals and insects; and the fourth of plants and fruits. These valuable volumes were lost to the scientific world for about a century and a half, and were only lately discovered in the Royal Library of Berlin by Lichtenstein, the professor of zoology. Had they been earlier found, Linnæus, Buffon, Brisson, and others, would have been spared a world of learned doubt and conjecture. The smaller drawings in water colours have also been discovered, and they contain many figures not in the larger collection of oil paintings. That nothing might be wanting for the elucidation of the work of Margrave, even Prince Moritz's copy of Margrave's work, with the Prince's own remarks, has been lately discovered in Germany. By

means of these materials, Professor Lichtenstein has been enabled to correct the apparent inconsistencies in Margrave's work, and to prove the accuracy of his descriptions and observations.

After the publication of the Natural History of Brazil, nothing more was done for upwards of a century, because naturalists were not permitted to travel into the interior of the country. Siebers, who was sent to Brazil by that patriotic and enlightened German naturalist Count Hoffmansegg, was the first who published any observations of importance. In later times, it is true, several naturalists of Vandelli's school have travelled in Brazil; but, with the exception of a few memoirs in the Transactions of the Lisbon Academy, and some ephemeral pamphlets of Feijo and Dr Couto, nothing is known to the public of what they accomplished. The two Velozos occupied themselves principally with the botany of Brazil, of which the Monk Velozo left behind a large Flora in manuscript. There also appeared in 1804, a small work on the present state of the mines of Brazil, by the Bishop of Elvas, Joze Joaquim da Cunha de Azeredo Coutinho. These were the principal writings in regard to Brazil, published before the arrival of the Royal Family from Europe. This event, so fortunate for Brazil, proved also most interesting and important for natural history. A country rich in the most beautiful and interesting productions of nature, was thus rendered accessible to foreigners, the former ill-judged and absurd restraints having been removed. Several interprising travellers, particularly Germans, have of late years visited this quarter of the New World; and it may be remarked as a singular circumstance in regard to Brazil, that Germans should have been its most distinguished investigators and historians. The English work of Mr Mawe of London, Eschwege remarks, is neither correct nor scientific; and the highly amusing and interesting History of our distinguished countryman Southey, contains principally such information as is found in the writings of Fathers Anchietta, Vas-consellos, Almeida, and in the works of the Jesuits Muriel, Montoja, and others.

An active and intelligent German miner and mineralogist, Von Eschwege, has resided in Brazil since the year 1810, and traversed in all directions the Capitania of Minas Geraes. In several of his journeys he was accompanied by the zoologist

M. Freireis, at present in the service of the Prince Regent of Portugal. The journals of his travels are printing in a periodical work entirely dedicated to Brazil, at present publishing in Germany.

But the most remarkable modern traveller in Brazil, is the German Prince MAXIMILIAN of Wied-Neuwied. This enterprising and distinguished person left Europe for Brazil in the month of June 1815. He went without parade or show, for the principal companions of his journey were two men of humble but respectable stations in life; the one was the gardener Simonis, a man of sound judgment, great knowledge, uncommon activity, and fearless of danger; and the other an experienced and expert huntsman. To these, when he landed in Brazil, the Prince added the necessary guides, huntsmen, and attendants. Thus accompanied, he traversed the woods, and marshes, and mountains of a tract of Brazil, extending from south latitude 13° to 23°. For months at a time he was encamped in the midst of vast forests, swarming with musquitoes, and crawling with serpents; and frequently his party were weeks in cutting their way through forests hitherto untrodden by man. The Prince himself was not an idle or inactive spectator; he directed all; he was perpetually occupied in determining the numerous objects he collected, or that were brought to him; he was ever on the watch to notice and record the appearance, habits, and manners of the numerous remarkable animals that presented themselves to his attention; and he did not allow the various magnificent and beautiful forms of the vegetable world to escape his penetrating glance. The appearance of the native tribes and their state of society, particularly of the cannibal Botocudos, afforded him a most interesting field for observation. Our admiration of the perseverance of this intrepid traveller is increased, when it is known that the tremendous and almost incessant rains to which he was exposed, did not for a moment excite any hesitation as to the prosecution of the journey; on the contrary, week after week, and month after month, suffering in a close, moist, and oppressive atmosphere, and tormented with vermin, he continued to traverse the marshes and deep and wet forests of vast unknown tracts. At night, after the fatigues of the day, huts were to be erected, fires kindled, and be

fore sleep could be indulged in, their collections must be dried, their sketches finished, and their packages completed. Many of the party, we are told, were never free from disease; for months they were in a state of fever, and yet still continued, under the animating and enthusiastic example of the Prince, to travel onwards.

The result of this remarkable journey, has been the collection of a more curious and extensive series of observations, and of the natural productions of Brazil, than has been made since the days of Prince Moritz. We are informed, that Prince Maximilian has brought, amongst other collections, the following with him to Neuwied: A series of human skulls of the different tribes of savages, and also those of several quadrupeds, which have not hitherto been examined by naturalists; 76 different species of quadrupeds; about 400 distinct species of birds, of which there are 2,500 specimens; 79 different species of amphibious animals, particularly many beautiful snakes; upwards of 5000 insects, of which many are entirely new; a few shells and fishes; 5000 plants, and a vast collection of seeds; and a portfolio of 200 drawings, made by the Prince, of scenery, different tribes of savages, and other objects of natural history.

We are happy to learn that the Prince of Neuwied has announced his intention of publishing an account of his travels, and of the various objects of natural history he has met with, in four volumes quarto, with maps and plates*.

ART. XIX.-Account of the Method of colouring Agates. By JOHN MACCULLOCH, M. D. M. G. S. Lecturer on Chemistry to the Board of Ordnance, &c. In a Letter to Dr BREWSTER.

IN compliance with your request, I here send you the circum

stances which I am able to recollect respecting the colouring of

We have just seen a work in two volumes quarto, published at Rio de Janeiro, in 1817, entitled "Corographica Brazilica," certainly the most important literary production which Brazil has hitherto afforded. It contains a pretty accurate description of the geography of the country, of its various tribes of original inhabitants, and treats fully of its moral and political condition; but the natural history is considered in a superficial and unscientific manner.-ED.