January 31, 1895] 



NATURE 



323 



of the neighbourhood occurred an interesting; Oslracod, 

 Cydocypris globosa ; and in the White Loch, a species 

 still more interesting and more capricious in its dis- 

 tribution, Paiwinula Stevensoni. 



As regards the botany of the district, 1 can say very 

 little. My last two visits were made about midsummer, 

 and at that time the sea banks were gorgeous with masses 

 of thrift and red cranesbill {Ccmniuir. sii>ii;!i!neii»i), 

 the marshy flats with golden fields of w;iter-tlag, the 

 fells with thickets of Rosa s/'iiiosissiiiia and numerous 

 orchids, the most conspicuous of which was the sweet- 

 scented species, Gviiinaden!,/ coiiofisen. These, of course, 

 are all flowers which cannot be overlooked, and are 

 an ever-present delight to the eye and mind : less 

 alluring species, which need to be hunted for, were for 

 the most part passed unnoticed, and such as 1 did gather 

 were of no particular interest. 



G. Stevvardson Brady. 



PROFESSOR ARTHUR CAYLEV, E.R.S. 



MATHEM.'\T1CAL science has suffered a grievous 

 loss by the de^th of Prof. Cayiey, which occurred 

 on Saturday last, at Cambridge. There is hardly a 

 branch of pure mathematics which is not indebted to 

 him for original contributions of the highest vaiue, while 

 the important problems which have been elucidated by 

 him are so numerous, and cover so wide a field, that he 

 was certainly one of the greatest mathematicans which 

 the world has ever known. 



It was in September 1S83, when Cayiey was President 

 of the lirilish .Association, that he was ranked among 

 our " Scientific Worthies," Dr. G, Salmon being his 

 biographer. We refrain, therefore, from giving a long 

 rotice of his life, and content ourselves with a Ltief 

 sketch of his scientific work. 



Cayiey was born Augu-t 16, iy2i,at Richmond, Surrey. 

 At a very early age he showed great liking and aptitude 

 for arithmetical calculations. He entered King's College 

 School, London, at the age of fourteen, and three years 

 later went to Cambridge, where he entered Trinit\ 

 College. In 1842 he came out as Senior Wrangler and 

 First Smith's Prizeman. Sir (Jeoige Stokes had been 

 Senior Wrangler in the previous year, and the late Prof. 

 Adams obtained the distinction in 1S43. 



While still an undergraduate, Cayiey commenced his 

 career of mathematical publication by a paper in the 

 Cambridge Mathematical Joainal for iS4i,but it was 

 not until 1852 that he addressed a memoir to the Royal 

 Society, of which he was elected a Fellow in the same 

 year. Very soon after taking his degree at Cambridge, 

 he entered the legal profession, and was called to the 

 Bar in 1849. But during his career as a barrister, he was 

 constant to his first love, mathematics, and it was while 

 in legal practice that some of his most brilliant mathe- 

 matical discoveries were made. In 1S63, after fourteen 

 years of chamber life in Lincoln's Inn, he returned to 

 Cambridge to fill the newly-instituted .Sadlerian Pro- 

 fessorship of Mathematics, and no one could have been 

 better fitted than he to discharge the duties of the holder 

 of the chair, viz. "' to explain and teach the principles of 

 pure mathematics, and to apply himself to the advance- 

 ment of the science." 



With regard to Cayiey as an original investigator, his 

 special merit has been described by Mr. (ilaisher. who 

 termed him "the greatest living master of algebra." It 

 is difficult to select the work for which he will be the 

 best remembered, but Prof. Salmon defined it as "his 

 creation of an entirely new branch of mathematics by 

 his discovery of the theory of invariants, which has 

 given quite a new aspect to several departments of 

 mathematics . . . .\nd the effect has been that the 

 knowledge which mathematicians now possess of the 

 structure of algebraic forms is as different from what it 



NO. I318, VOL. 51] 



was before Cayley's time as the knowledge of the human 

 body possessed by one who has dissected it and knows 

 its internal structure is different from that of one who- 

 has only seen it from the outside." 



Among the honours which Cayiey received, may be 

 mentioned the Royal Medal of the Royal Society, 

 awarded to him in 1S59, and the Copley Medal in 1882. 

 He was a correspondent in the section of .Astronomy of the 

 Paris Academy cf Sciences, and was a Fellow or Foreign 

 Member of many other societies and academies, both at 

 home and abroad. He was given the honorary degrees 

 of D.C.L. by the University of Oxford in 1S64, and the 

 LL.D. by Dublin University in the following year. 

 Later, the University of Edinburgh conferred upon him 

 a similar honour, and he received the degree of Sc.D. 

 from his own University. The Universities of Leyden. 

 Gdttingen, and Bologna also conferred upon him the 

 degree of Ph.D. In 1890, the President of the French 

 Republic made him an officer of the Legion of Honour. 

 This distinction was granted in consequence of a 

 request addressed to the French Minister of Foreigiv 

 Affairs by the President and other members of the 

 Academy of .Sciences. 



Cayley's mathematical papers, commencing in the 

 year 1S41, have .ippeared in every periodical mathemat- 

 ical publication of importance in Europe and America. 

 In the year 1887 he undertook the work of editing the 

 series of ten quarto volumes, in which the Syndics of the 

 Cambridge University Press are publishing his collected 

 mathematical papers. The publication of these volumes 

 commenced in 1889, and six of the volumes were re- 

 viewed in these columns a year ago (Nature, January 18, 

 1S94). The number of papers which appear in the six 

 volumes is 416. Altogether seven volumes have as yet 

 appeared. As Cayiey is responsible for 724 titles in the 

 Royal Society Catalogue down to 1883, and he has since 

 produced a considerable amount of mathematical work, 

 it seems improbable that ten volumes will be sufficient 

 to contain the results of his prodigious activity and 

 enormous literary industry. 



What more need be said about this great master of 

 mathematics.- He sacrificed prospects of advancement 

 in the law in order to follow the mathematical work to 

 which he was devoted. He had the power to teach, and 

 the ability to extend the boundaries of knowledge. He 

 was " as distinguished for the amount and universality of 

 his reading as for his power of original work." Truly, 

 his memory will " outlive the life of dust and breath." 



The funeral service will take place in the Chapel of 

 Trinity College to-morrow (Friday). Lord Kelvin will 

 be present to represent the Royal Society, and other 

 men of science will probably attend to do honour to the 

 memory of their brilliant fellow-worker. 



NOTES. 



We are enabled to stale that the communication to the Royal 

 .Society on " Argon, a new Constituent of Air,' by Lord Ray- 

 leigh and Prof. Ramsay, to be given at the Royal Society 

 today, will refer to the density of nitrogen from various 

 sources : to methods for removing free nitrogen from air ; to 

 the separation of argon from air by ditTusion ; to the density of 

 argon ; to its spectrum (on which a short paper will be read by 

 Mr. Crookes) : and to its behaviour at low temperatures. It is 

 interesting to note that Prof. 01szew>ki, of Cracow, has lique- 

 fied and solidified the gas, and will communicate a short paper 

 on the subject. The solubility in water is also recorded. 

 Various attempts to induce chemical combination are described, 

 and general conclusions arc drawn in a final section. The 

 ratio of its specific heats shows it to be a monatomic gas, and 

 proves that its atomic weight is approximately 40. The 

 meeting will not be held in the apartments of the Royal Society, 

 but in the theatre of the University of London. 



