SOT 



ORES', LORENZ. 



OLBERS, HENRICH WILHELM MATHIAS. 



558 



was a Roman Catholic to the last. He died at Southampton, on the 

 4th of February 1833. In 1834 appeared a email volume of his ver- 

 sified pieces, entitled ' O'Keeffe's Legacy to his Daughter,' and prefaced 

 by notices of his character and domestic circumstances. 



OKEN, LORENZ, a celebrated Swiss naturalist, was born at 

 Offenbert; on the 2nd of August 1779. He studied medicine and 

 natural history at Gbttingen, and held the position of privat-doceiis 

 in that university. In 1807 he became extraordinary professor of 

 medicine in the University of Jena ; thence he removed to Zurich, 

 where he held the post of professor of natural history till his death. 

 At the time he began to study natural science, the writings of Kant, 

 Fichte, and Schelling were producing a deep impression on the minds 

 of the students of natural history. Schelling, who had studied 

 medicine, bad applied the principles of the transcendental philosophy 

 to the facts of the natural world, and had ' by a process of thought 

 endeavoured to give an explanation to the phenomena of nature. It 

 was in this school that Oken studied, and the principles of the tran- 

 scendental philosophy more or less guided his researches as a naturalist 

 throughout his long life. His first work was published in 1802, and 

 was entitled ' Elements of Natural Philosophy, the Theory of the 

 Senses, and the Classification of Animals founded thereon.' This was 

 followed by a work 'On Generation ' in 1805. In these works he 

 endeavoured to apply a general theory of nature to the facts presented 

 by the form* and the development of animals. In his classification 

 he took for his basis the presence of the senses, making each class of 

 animals to represent an organ of sense. In his work ' On Generation' 

 he first suggested that all animals are built up of vesicles or cells. 

 In 1306 he published his 'Contributions to Comparative Anatomy 

 and Physiology,' and pointed out the origin of the intestines in the 

 umbilical vesicle. In this year he made an excursion to the Harz 

 Mountains, which resulted in an important thought. This may be 

 described in his own language : " In August 1806," he says, " I made 

 a journey over the Harz. I slid down through the wood on the 

 south side ; and straight before me, at my feet, lay a most beautiful 

 bleached skull of a hind. I picked it up, turned it round, regarded it 

 intensely: the thing was done. 'It is a vertebral column!' struck 

 me, as a lla-h of lightning to the marrow and bone ; and since that 

 time the skull has been regarded as a vertebral column." This 

 discovery was published in an essay on the 'Signification of the 

 Bones of the Skull.' This essay, although it attracted little atten- 

 tion at first, laid the foundation of those inquiries which in the 

 hands of Cams, Geoffrey St.-Hilaire, and Owen, have led to the 

 establishment of those laws of homology in the vertebrate skeleton 

 that are now a universally-received branch of anatomical science. It 

 was by the persevering use of the idea that flashed across his mind in 

 the Harz, that Oken lias earned for himself the title of " the father of 

 morphological science." 



Whilst still n young man and deeply convinced of the importance 

 of an ideal philosophy in explaining the phenomena of the external 

 world, he wrote his ' Lehrbuch der Natur-Philosophie.' This work 

 was published in 1809, and after having gone through three editions, 

 it was translated into English by Mr. Fulke, and published in 1847, 

 by the Ray Society, with the title 'Elements of Physiq-Philo- 

 tophy.' In this work the author takes the widest possible view of 

 natural science, and classifies the mineral, vegetable, and animal king- 

 doms according to his philosophical views. The transcendental philoso- 

 phy has never been popular in England, and its language is entirely 

 foreign to that adopted by the generality of writers on natural history 

 in this country, so that this work has been frequently regarded as the 

 offspring of a diseased imagination rather than the cool decisions of a 

 philosopher. Nevertheless, its author was pleased at its translation, 

 and wrote a preface to the English edition. Of however little value 

 this work may be as an introduction to modern science, it is interest- 

 ing as a document in the history of a great mental movement, and 

 contains the germs of those principles which are now regarded as the 

 secure generalisation of well-observed facts. 



From the date of the publication of this work to the day of his 

 death, Oken unceasingly contributed to the literature of natural 

 history. In the year 1817, he started a natural history journal, 

 named ' Isis,' which he conducted for thirty years, and which con- 

 tains a large series of his papers on every department of natural 

 history. Though a transcendentalist in philosophy, he was an energetic 

 and acute observer, and has contributed largely to the individual 

 history of the animal kingdom. 



He was greatly respected throughout Germany, and it was at his 

 suggestion that the first meeting of natural philosophers took place in 

 1822. The German Association which thus came into existence, has 

 assembled every year in one of the large towns of Germany, whilst 

 every country in Europe has imitated this example with great and 

 increasing success. Oken died full of years and honour, at Zurich, in 

 August 1847. 



OLAT'S MAGNUS, a native of Sweden, and brother of John Olaus, 

 archbishop of Upsala, was an archdeacon in the Swedish church when 

 the Reformation, supported by Gustavua Vasa, gained the ascendency 

 in Sweden. In consequence of this change the two brothers, who re- 

 mained attached to the Roman Catholic faith, left their country and 

 retired to Rome, where Olaus Magnus passed the remainder of his 

 life in the enjoyment of a small pension from the pope. At Rome he 



wrote his work, ' Historia de Gentibus Septeutrionalibus, earumque 

 diversis Statibus, Conditionibus, Moribus, itidemque Superstitionibus, 

 Disciplinis,' &c., Rome, fol., 1555, and Basel, 1567. Other editions of 

 this work have been published, which, as well as a French translation 

 in 1561, are all incomplete. The work is minute, and contains some 

 curious information, but is uncritically written. Olaus died at Rome 

 in 1568. His brother John wrote a work entitled ' Qothorum Sue- 

 vonumque Historia, probatissimis Antiquorum monumentis collecta,' 

 Rome, fol., 1554, which is a still more uncritical performance thaa 

 that of his brother Magnus. 



OLBERS, HKNRICH WILHELM MATHIAS, an able physician 

 and a distinguished astronomer of Germany, was born on the llth of 

 October 1758, at Arbergen, near Bremen. He studied medicine at the 

 University of Gb'ttingen, and during all his life his time appears to 

 have been divided between the exercise of his profession and hia 

 astronomical researches. It is said that in 1830 he celebrated by a 

 public festival the fiftieth anniversary of his medical labours ; and 

 his observatory is described as the most complete of those which at 

 the time of its construction existed in Germany. It consisted of 

 three rooms in the upper part of the house, which was situated iu the 

 heart of Bremen : three great windows in the south front gave a vie'.v 

 of the heavens almost to the horizon on that side, and one in a closet 

 enabled the observer to look towards the north : opeuings in tho 

 ceiling and roof permitted observations to be made near the zenith. 

 Olbers possessed a five feet achromatic telescope, with a po.-ition 

 micrometer by Dollond, and a reflecting telescope of equal length by 

 Schroter. He had also an astronomical clock by C;irsten, a quadrant 

 by Bird, and a reflecting sextant by Troughton ; but he had neither a 

 transit instrument nor a mural circle ; and apparently he determined 

 his time by extra meridional altitudes. Attached to the observatory 

 was an astronomical library, containing, among other valuable works, 

 an exteusive collection of documents relating to cometography. This 

 library was, after the death of Olbers, purchased by the Emperor of 

 Russia, snd deposited in the observatory of Pulkowa. 



Dr. Olbers wrote but little on the subject either of medicine or 

 astronomy; but in 1780 he printed a thesis entitled 'De Oculi 

 Mutationibus Internis,' in which he showed that the eye accommodates 

 itself to the different distances of objects from it by means of a variable 

 action of the muscles, in consequence of which changes are produced 

 in the convexity and the focal length of the cornea; and in 1832 he 

 published, in the ' Anuuaire du Bureau dos Longitudes,' a memoir 

 entitled ' Do 1'Influence de la Luue sur les Saiaous et sur le Corps 

 Humain.' 



In 1779 he became known to astronomers by a series of observations 

 which he made on the comet of that year, and by his determination 

 of the elements of its orbit : the computations were founded on a 

 method which had been given by Euler; but, at a subsequent period, 

 Olbers discovered a method of calculating the orbits of comets from 

 three observation*, which, with respect both to facility and accuracy, 

 he considered as having great advantages over the methods before iu 

 use. An account of this method, with a preface by the Baron de 

 Zach, was published at Weimar iu 1797. It is entitled ' Abhandlung 

 uber die leichteste und bequemste methode die Bahn eiues Cometeu 

 aus einigen Beobachtungen zu berechneu,' and it affords sufficient 

 evidence that the talents of the author as a mathematician were con- 

 siderable. An outline of the method, with its application to an 

 example, is given in Delambre's ' Astrouomie ' (torn. iii. Nos. 184, 223, 

 &c.). Olbers computed also the orbits of the comets which appeared 

 in 1781 aud 1795 ; those of two comets which appeared in eacli of 

 the years 1798 and 1799; of one in 1802; and of the great comet 

 of 1811. 



The interval between the orbits of Mars and Jupiter, which appears 

 disproportionably great when compared with the intervals between 

 any two of the other planets belonging to our system, had suggested 

 to the original and inquisitive mind of Kepler the idea that a planet, 

 too small to be seen from the earth, existed in that region : the idea 

 appears to have been little regarded till M. Bode, of Berlin, obtained 

 his empirical formula, for the distances of the planets from the sun, 

 which except with respect to the interval between Mars and Jupiter was 

 found to hold good for all the known planets, including the Georgian ; 

 when that which was before considered as the vision of an enthu- 

 siast was found to be deserving of serious consideration. With a 

 view therefore of ensuring, as far as possible, a complete examination 

 of the heavens in the parts where the supposed planet might be 

 expected to be found, M. Schroter was induced to form an association 

 of twenty-four astronomer*, Olbers being one, who, having divided 

 the heavens into as many zones, were each to confine his observations 

 to one of them. The labours of the association were not however 

 immediately rewarded; and M. Piaz/.i, of Palermo, who was not one 

 of the number, had the good fortune to discover January 1, 1801, a 

 planet, to which he gave the name of Ceres, and which was found to 

 be between the orbits of Mars aud Jupiter, at a distance from the sun 

 nearly equal to that which, in conformity to the law discovered by 

 Bode, it ought to have. 



This planet soon afterwards became invisible, from its vicinity to 

 the sun; but Dr. Olbers and M. Gauss, having calculated its orbit 

 approximative^ from such observations as had been obtained, sought 

 for it at the time when it was expected again to appear, and tho 



