1029 



WALLICII, NATHANIEL, M.D. 



WHEATSTONE, CHARLES, F.R.S. 



1030 



claim to priority of discovery is undisputed. The eighth had been 

 observed by another astronomer two days before it was discovered 

 (independently however) by Father de Vieo. 



Another more humble but hardly less useful work undertaken by 

 Father de Vico, was an improved and enlarged system of astronomical 

 maps and charts, in which he is said to have made considerable pro- 

 gress ; but in this and other works which he had commenced, he was 

 interrupted by the Revolution of 1848, by which, in common with the 

 other members of his order, he was driven from Rome. He was treated 

 with much distinction during his exile by his fellow-astronomers in 

 France aud England, and received more than one invitation to fix his 

 residence in either of these countries ; but the circumstances of his 

 order at that time determined him upon establishing himself in the 

 United States of America, and he had almost completed his arrange- 

 ments for the purpose, when he was seized with acute inflammation 

 of the chest, and was carried off after a short illness. He died in 

 London on the 15th of November, 1848, at the early age of forty-three. 

 Father de Vico is chiefly known iu literature by his contributions to 

 the ' Raccolta Scientifica,' a scientific journal which owed its origin 

 principally to himself, and which is still continued under a new form., 



(Ragguaglio intorno alia, Vita e ai Lavori del P. Francesco de Vico, 

 Roma, 1851.) 



WALLICH, NATHANIEL, M.D. and Ph. D., F.R.S., London and 

 Edinburgh, a celebrated botanist, was born at Copenhagen on Jan. 

 28th, 1786. He commenced his botanical studies uuder the direction 

 of Professor Vahl, and went to India in 1807 at the age of one-and- 

 twenty in the capacity of surgeon to the Danish settlement at Seram- 

 pore. In 1815 he was nominated to the temporary charge of the Calcutta 

 Botanic Garden, which appointment was subsequently permanently 

 confirmed on the recommendations of Dr. Fleming, Mr. Colebrooke, and 

 Sir Joseph Banks. Dr. Wallich's exertions during the thirteen years that 

 elapsed before his first return to Europe added greatly to the extent 

 and value of the previously extensive collections of this garden. He 

 also transmitted to Europe and America a vast quantity of hitherto 

 unknown and beautiful plants. In 1820 Dr. Wallich made a botanical 

 excursion to Nepaul, in the course of which he collected a great variety 

 of plants, many of which he forwarded to London. A severe fever, 

 caught? 1 on his descent to the plains, confined him to his bed for two 

 mouths and compelled him to seek benefit from a voyage to Penang, 

 Singapore, and some other places in the Straits of Malacca, from which, 

 after an absence of five months, he returned on the last day of the 

 year 1822, rich in botanical collections and with renewed health. In 

 1824 he commenced the publication of a selection from his Nepaul 

 collections under the title of ' Tentamen Flora Nepalensis Illustratse,' 

 of which two numbers, containing 25 plates, were issued. These plates 

 were the botanical first fruits of the new art of lithography in India, 

 and both drawings and lithographs were executed by native artists 

 under Dr. Wallich's direction. 



In the following year he was deputed by the government to inspect 

 the timber forests of the Western Provinces, and availed himself of 

 this opportunity to examine and collect plants in the kingdom of 

 Oude, the valley of Degra, &c. Excursions to other parts of India 

 were undertaken at various times by Dr. Wallich, which enabled him 

 still further to increase the immense stores of botanical treasure he 

 had accumulated. His health had now however suffered so severely 

 from repeated attacks of illness that, in 1828, he visited England, 

 bringing with him the great bulk of his collections. He then with 

 the consent of the East India Company proceeded to distribute his 

 duplicate specimens amongst the public and private herbaria through- 

 out the world. The type collection, containing a complete series of all 

 the species, was presented by Dr. Wallich to the Linnsean Society of 

 London. At this time he completed his work, entitled ' Plantsc 

 Aaiaticse Rariores,' consisting of 300 beautifully executed coloured 

 plates. In 1833 Dr. Wallich returned to India and resumed the 

 charge of the Botanical Garden, which however his health obliged him 

 finally to resign in 1847, when he again arrived in England. He was 

 the author of numerous papers and reports on horticultural and bota- 

 nical subjects, published in the ' Transactions of the Asiatic Society cf 

 Calcutta,' Sir W. J. Hooker's * Journal of Botany,' and the ' Linnsean 

 Transactions.' He became a Fellow of the Linnsean Society in 1818, 

 and in 1849 one of its vice-presidents. He was a man of warm affec- 

 tions, ready wit, and pleasing manners, and devoted in his attachment to 

 his favourite science. It must not be forgotten that he did more than 

 any one else, to introduce into the gardens and greenhouses of Eng- 

 land the beautiful and luxuriant plants of India, and it is from hia 

 collections and desciiptions, and presentations to our public and 

 private gardens that we are indebted more than to any other source 

 for our acquaintance with the Flora of that district. 



He died at his house in Upper Gower-street, London, on the 28th 

 of April 1854, in the 69th year of his age. 



* WHEATSTONE, CHARLES, F.R.S., Professor of Experimental 

 Philosophy in King's College, London, was born at Gloucester in the 

 year 1802. Connected from his birth with business related to the 

 musical profession, his career presents an instructive and gratifying 

 instance, in addition to many we have already recorded, of the happy 

 effects of the devotion of leisure to scientific study, and of the manner 



in which the ranks of science are recruited from those of trade. But 

 this instance is of a peculiar kind. Mr. Wheatstone, as a seller and 

 maker of musical instruments, in London, was led to investigate the 

 science of sound, both theoretically and practically. His first contri- 

 bution to science, we believe, was founded on some ' New Experiments 

 on Sound,' made at an early age, and published in the ' AnnaU of Phi- 

 losophy,' N.S., for August 1823. Uniting great mechanical ingenuity 

 with clear geometrical conceptions of pure dynamics, he produced from 

 time to time, a variety of instruments and pieces of apparatus, for the 

 illustration of mechanical and acoustic principles, and the production 

 of experiments both of research and demonstration ; among which 

 were many (some founded on Dr. T. Young's harmonic sliders,) for 

 the explanation of the nature of waves and undulations and the mode 

 of their progression, interference, and combination. The study and 

 illustration of the philosophy of sound led to that of the philosophy 

 of light, and in this has consisted the peculiarity of Mr. Wheatatone's 

 career, which, we conceive, affords something very like a practical 

 demonstration of the undulatory theory of light. Had not that theory 

 been essentially true were not light, equally with sound, pro- 

 duced by the undulation of an elastic medium had light consisted 

 in the projection of corpuscles did not acoustics and optics present 

 an harmonious system of perfect mutual analogies we believe Mr. 

 Wheatstone would not have been led from music to light, and from 

 optics to electricity, and could not have made himself the philo- 

 sopher he has become. His apparatus and instruments for the 

 production upon true theoretical principles, or the imitation of such 

 production and the explanation of optical phenomena, are almost as 

 numerous and valuable as those illustrating sound, with which, indeed, 

 some of them are necessarily identical. The tardy justice with which 

 the truth of Dr. Young's [YOUNG, THOMAS] great discoveries in con- 

 nexion with the undulatory theory has at last been recognised, by the 

 educated "portion of the public, and the intellectual appreciation in this 

 country of Fresnel's consentaneous researches, are both greatly indebted 

 to Mr. Wheatstone for the production of experimental devices, enabling 

 the student to obtain a rational conception of the theory to perceive 

 in relation to that subject, " that central thread of common sense, on 

 which," in the words of Sir John Herschel, " the pearla of analytical 

 research are invariably strung." 



After numerous acoustic and optical investigations, made public in 

 the later Journals of the Royal Institution (some of which were 

 announced and illustrated at the weekly evening meetings), or in the 

 'Philosophical Magazine,' including experimental inquiries into the 

 principles of various musical instruments, he communicated to the 

 Royal Society, in 1833, through Professor Faraday as a Fellow, a 

 paper on the Acoustic figures which had been summarily investigated 

 by Chladni. In the following year he communicated to the society, 

 through the same medium, his celebrated ' Account of some experi- 

 ments to measure the velocity of electricity and the duration of 

 electric light.' In the same year (1834) he was appointed Professor of 

 Experimental Philosophy in King's College, London. On the 21st of 

 January 1836, he was elected a Fellow of the Royal Society. On the 

 21st of June 1838, he communicated a paper to the society (which 

 was read on the same day,) entitled, ' Contributions to the Physiology 

 of Vision. Part I. On some remarkable and hitherto unobserved 

 phenomena of binocular vision.' In this he first described the beau- 

 tiful instrument he named the Stereoscope, now, in various forms, 

 and with various modifications and additions, so well-known. 



But though the stereoscope has deservedly become an object of 

 refined popular admiration, Professor Wheatstone is far better known 

 to the general public, from the application of his scientific genius and 

 attainments to the Electric Telegraph, to the hietory of which, in 

 connection with himself and with his original co-patentee, Mr. WILLIAM 

 FOTHERGILL CooKE, we must now proceed. 



For between sixty and seventy years past, various philosophers have 

 from time to time exhibited experiments on frictional, and on voltaic 

 electricity, in electro-magnetism, and in magneto-electricity as each 

 branch of the subject became developed all considered as possible 

 means of communicating intelligence. These gradually improved 

 in definiteness of object, and in the approaches they made to prac- 

 ticability. Dr. Hamel of St. Petersburg, has recently asserted (in a 

 discourse delivered at the meeting at Bonn, in the autumn of 1857, of the 

 German naturalists and physicists,) that the first electro-magnetic tele- 

 graph was produced, between 1820 and 1832, by the Baron Schilling, 

 of Lanstadt, who had been attached to the Russian embassy at 

 Munich, and become familiar with the previous endeavours of the 

 Bavarian electricians. At the sitting of the Physical section of the 

 meeting at Bonn, in 1835, on September 23rd, of which Professor 

 Muncke of Heidelberg was president for the day, the Baron explained 

 and exhibited his telegraph. The subject received much continued 

 attention from Professor Muncke, who, on the 6th of the following 

 March, 1836 in the words of Dr. Hamel, "explained the whole thing " 

 to Mr. Cooke, at that time occupied in the Anatomical Museum at 

 Heidelberg, in preparing wax models for his father, who had then 

 recently been appointed Professor of Anatomy in the University of 

 Durham. He had not previously studied physics or electricity ; but 

 being struck with the vast importance to the railways then extend- 

 ing themselves over Great Britain, as well as to government and gene- 

 ral purposes, of a (virtually) instantaneous mode of communication, 



