December 6, 1894J 



NA TURE 



•37 



of many gases and vapours, and proved the non-conducting 

 power of several others", founding on the conducting power of 

 iodine vapour important speculations as to its probable 

 chemical constitution. 



He has also measured the specific resistance of various 

 electrolytes, under extremely rapid electric oscillations, by an 

 ingenious and valuable method, based on the partial opacity of 

 semi-conducting matter to electromagnetic waves. Recently 

 he has worked at the discharge of electricity thiough rarefied 

 gases, getting induced currents in closed circuits in sealed bulbs 

 without electiodes, and, in especial, measuring to a first ap- 

 proximation the absolute velocity of the positive discharge through 

 a long vacuum tube, proving that it was comparable with, 

 though decidedly less than, the velocity of light. lie also gave 

 an ingenious theory of the striae— a theory which he has since 

 endeavoured, with some success, to extend to a large number of 

 electrical phenomena, the whole of electric conduction and in- 

 duction being regarded by him from the chemical side as a 

 modified or incipient electrolysis, or as concerned with electro- 

 lytic chains of molecules or " Faraday tubes." 



Some of his recent mathematical work on the theory of 

 electric oscillations in spheres and cylinders, and in dumb-bell 

 oscillators of the kind used by Hertz, with reference to not only 

 their oscillation-frequency but also their damping efficiency, 

 has been of much service to experimental workers in those 

 branches of physics. And, in general, the effective manner in 

 which he attacks any electrical problem presenting itself, as 

 evidenced by his book on " Recent Researches iii Electricity 

 and Magnetism," wherein he worthily carries on into a thiid 

 volume the great treatise begun by Clerk Maxwell, is evidence 

 of consummate ability combined with remarkable energy and 

 power of work. 



Royal Medal. 

 Picf. Victor HorsUy, F.R.S. 



A Royal Medal is awarded to Prof. Victor Horsley, F.R.S., 

 for his laborious and fruitful researches in physiology and 

 pathology, and particularly for those relating to the functions of 

 the nervous system and of the thyroid gland. His inquiries 

 relating to the former subject have been pursued for more than 

 ten years, and have been communicated to the Royal Society in 

 a succession of papers, the most important of which have been 

 published in the Philosophical Transactions. The first of the 

 series of researches (/'/;;/. Trans., |8S8), which was conducted 

 in co-operation with Prof. Schiifer, and concerned the relation 

 of a part of the cerebral cortex (the limbic lobe) to sensation, 

 afforded a new confirmation and extension of the doctrine of 

 the localisation of cerebral function now generally accepted. 

 While this work was in progress. Prof Horsley engaged with 

 Dr. beevor in a long and laborious series of experiments for the 

 purpose of determining with the utmost attainable accuracy the 

 nature of the muscular responses which are evoked by stimulat- 

 ing the convolutions in the quadrumana. The results of these 

 researches were communicated in four papers, of which the first 

 three relate to the "cortical representations ' of the movement 

 of the limbs, and of those of the tongue and face (/'/;// Trans., 

 1887-1890) ; the fourth on the channels (in the internal capsule) 

 by which the cortex exercises its influence on the rest of the 

 nervous system (/VhY. Trans., 1S90). 



These experiments not only served to bring to light a number 

 of new facts, and to elucidate their physiological relations in a 

 very remarkable way, but had a special interest in their bearing 

 on the physiology and pathology of the brain in man. Their 

 importance in this respect is enhanced by the circumstance that 

 in the course of the inquiry the opportunity offered itself of 

 comparing the brain of the monkey with that of the orang 

 (Phil. Trans., 1890), a brain which so closely approaches that 

 of man in its structure that the knowledge acquired by these 

 researches may now be confidently used as a guide in the dia- 

 gnosis and treatment of cerebral disease. Prof. Horsley has 

 himself shown — and this is not the least of the merits which it 

 is desired to recognise in the bestowal of the Royal Medal — in 

 how many instances the knowledge which is acquired by patient 

 and skilful work in the laboratory may be made available for 

 the saving of life, or the alleviation of human suffering. 



In connection with this leading series of researches, two 

 others relating to the physiology of the central nervous system 

 must be referred to. In one of these {Phil. Trans., 1890), 

 Prof. Horsley (in co-operation with Dr. Semon) established the 

 existence, not only of a co oniinating centre in the liulh, but of 



NO. 1310, VOL 5 l] 



a cortical area in physiological relation with the respiratory and 

 phonatory movements of the larynx ; in the other, in conjunc- 

 tion with Prof. Golch, he investigated the electrical changes in 

 the spinal cord which are associated with excitation of the 

 cortex and internal capsule, and showed how the observation of 

 these facts can be made available for tracing channels of con- 

 duction in the cord. 



As regards the thyroid gland, Pi-of. Horsley's inquiries relat- 

 ing to functions of that organ were like those relating to the 

 nervous system, begun ten years ago, though the results were 

 not communicated to the Royal Society until three years later. 

 Their purpose was to ascertain the nature of the very marked 

 influence which the thyroid was known to exercise on the 

 nutritive functions of the organism, and to show that ihis influ- 

 ence is constant and definite. In this field. Prof Horsley has 

 not only the merit of having been one of the earliest workers, 

 but of having at ihis early period arrived at results which the 

 numerous investigations of subsequent writers have in all 

 essential particulars confirmed. 



D.WY Medal. 

 Prof. Peter Theodor Clez'c. 



The Davy Medal is awarded to Peter Theodor Cleve, Pro- 

 fessor of Chemistry in the University of Upsala, for his services 

 to chemical science during the last thirty year.s, and in particular 

 for his long-continued and valuable researches on the chemistry 

 of the rare earths. 



This field of inquiry is pre-eminently Scandinavian. By the 

 manner in which he has cultivated it, Prof Cleve has shown 

 himself a worthy successor of such forerunners as Gadolin, 

 Berzelius, and Mosander, and by sound and patient investigation 

 he has faithfully upheld the traditions inseparably associated 

 with these names. All chemists are agreed that no department 

 of their science demands greater insight or more analytical skill 

 than this particular section. Many of the minerals which furnish 

 the starting-point for investigation are extremely rare, and the 

 amounts of the several earths which they contain are frequently 

 very small. Moreover, the substances themselves are most 

 difficult of isolation, and their characters are so nearly allied that 

 the greatest careandjudgment are requiredin order todetermine 

 their individuality. 



A remarkable example of Prof Cleve's power in overcorning 

 these difficulties is seen in his masterly inquiry into the affinities 

 and relations of the element scandium, discovered by Nilson. 

 This, one of the rarest of the metals, is found only in gadolinite 

 to the extent of o'OOj per cent., and inytirolitanite to the extent 

 of about 0'005 per cent. The whole amount of the material, as 

 oxide, at Cleve's disposal was only about I gram, but with 

 ihii small quantity he determined the atomic weight of the 

 element, and ascertained the characters of its salts with such 

 precision as to leave no doubt of the identity of scandium with 

 the element Ekabor, the existence of which w.as predicted by 

 Mendeleef, in the memorable paper in which he first enunciated 

 the Law of Periodicity. Cleve's research, indeed, constitutes 

 one of the most brilliant proofs of the soundness of the great 

 generalisation which science owes to the Russian chemist. 



A not less remarkable instance of Cleve's skill as a worker is 

 seen in his research on samarium and its compounds, which he 

 communicated as one of its Honorary Foreign Fellows to the 

 Chemical Society of London. The existence of samarium was 

 inferred independently by Delafontaine ami Lecoq de Bois- 

 baudran, but we owe to Cleve the first comprehensive in- 

 vestigation of its characters and chemical relations. From the 

 nature of its compounds, a large number of which were first 

 prepared and quantitatively analysed by Cleve, and from the 

 value of its atomic weight, which was first definitely established 

 by him, it would appear that samarium most probaoly fills a gap 

 in the eighth group of -Mendelcef s system. 



We are further indebted to Cleve for a series of determinations 

 of the atomic weights of the rare substances yttrium, lanthanum, 

 and didymium ; these are generally accepted as among the best 

 authenticated values for these particular bodies. 



No record of Cleve's scientific activity would be complete 

 without some reference to his investigations in the domain of 

 organic chemistry, and more particularly to his studies, extend- 

 ing over twenty years, of naphthalene derivatives. By these 

 researches, made partly independently, and partly in conjunction 

 with his pupils, among whom may be named .Vtterberg, Widman, 

 Forsiing, and Hellstr<im, Cleve has gradually brought order out 

 of confusion, and has supplied most valuable experimental 



