June 24, 1920^ 



NATURE 



525 



difficulties of transport, it has been necessary to 

 give up the proposed reception by Lord Treowen 

 on that afternoon, but it is hoped that arrange- 

 ments can be made for a visit to be paid to Llan- 

 over in connection with one or more of the Satur- 

 day excursions. 



A long list of works, factories, and other indus- 

 trial undertakings has been compiled, some of 

 which are sure to be of interest to the various 

 members of the association. 



Exhibitions will be a great feature of the meet- 

 ing. The National Museum of Wales is arranging 

 to display some of its treasures. There will be 

 an exhibition of pictures and charts for school 

 'decoration arranged by a committee of the asso- 

 ciation in connection with the educational section. 

 The botanical section is arranging a special ex- 



hibit, whilst collections illustrating the work of the 

 various corresponding societies are being arranged 

 in conjunction with the Cardiff Naturalists' Society. 



A reception, specially intended for the members 

 of Section I, will probably be given by Prof. 

 J. Berry Haycraft in the new physiological labora- 

 tories of the medical school. 



The list of foreign guests who have accepted 

 the invitation to be present includes the names of 

 MM. Bruno and Brioux, representing the French 

 Department of Agriculture ; Profs. Cayeux, 

 Laplae, Fauvel, and Yves-Guyot, from France; 

 Prof. Gilson, from Brussels ; Profs. Chamberlin, 

 Graham Lusk, and Kofoid, from the United 

 States ; Prof. Chodat, from Geneva ; Profs. 

 Hasselsbalch and Ostenfeld, from Denmark ; and 

 Don. G. J. de Osma, from Madrid. 



Obituary. 



Prof. 

 ROF. J. 



J. R. Rydberg, For.Mem.R.S. 



PROF. J. R. RYDBERG, who died in December 

 last after a long illness, made an enduring 

 contribution to science by his investigations of the 

 arrangement of lines in the spectra of the elements. 

 Rydberg was one of the earliest workers on this 

 subject, and he entered upon it with a full realisa- 

 tion of its significance in relation to the structure 

 of atoms and molecules. His classical memoir, 

 " Recherches sur la Constitution des Spectres 

 d'Emission des Elements Chimiques," was pre- 

 sented to the Swedish Academy in 1889, but he 

 appears to have arrived at his well-known general 

 formula before the announcement by Balmer, in 

 1885, of the formula connecting the lines of 

 hydrogen. 



Notwithstanding the imperfect spectroscopic 

 tables then at his disposal, Rydberg discovered 

 most of the important properties of series spectra, 

 including the relation between corresponding 

 series in the spectra of related elements, and fore- 

 shadowed discoveries which were made later, 

 when experimental work had sufficiently ad- 

 vanced. Some of the features noted by Rydberg 

 were observed about the same time by Kayser 

 and Runge, but his work had the special merit 

 of connecting different series in the spectrum of 

 the same element into one system, which could be 

 represented by a set of simple formulae having but 

 few adjustable constants. He especially insisted 

 that the hydrogen constant, now generally called 

 the "Rydberg constant," should appear in the 

 formulae for all series, and, apart from slight 

 variations from element to element suggested by 

 the theoretical work of Bohr, nearly all subse- 

 quent attempts to improve the representation of 

 series have involved this supposition, and have 

 had Rydberg's formula as a basis. 



Other valuable contributions to the subject were 

 made by Rydberg, but the memoir above men- 

 tioned is the most comprehensive of his published 

 papers ; it is a perfect model of a scientific investi- 

 gation, and may still be read with advantage by 

 all students of physics. 



Much attention was also given by him to the 

 NO. 2643, VOL. 105] 



I chemical and physical properties of the elements 

 I in relation to the periodic system, and in 191 3 he 

 [ published his suggestive memoir, " Untersuch- 

 I ungen iiber das System der Grundstoffe." His 

 I later work in this connection was seriously inter- 

 rupted by ill-health. 



Rydberg was born at Halmstad, in Sweden, on 

 November 8, 1854, and entered the University of 

 Lund in 1873. He obtained the doctor's degree 

 in mathematics six years later, and after holding 

 appointments in the departments of mathematics 

 and physics, was appointed professor of physics 

 in the University in 1901. About a month before 

 his death he had retired from his professorship 

 on reaching the age-limit of sixty-five years. He 

 was elected a foreign member of the Royal Society 

 in 1919. 



The death is announced of Prof. A. A. 

 Inostranseff, who was for many years professor 

 of geology in the University of Petrograd. Ino- 

 stranseff was born in 1843, ^'^^ began his geological 

 researches in Germany, where he was led to devote 

 special attention to petrology. His first paper, on 

 the microscopic structure of some Vesuvian lava, 

 was published at Halle in 1872. On his return 

 to Russia he made important observations on the 

 opaque minerals in crystalline rocks and on the 

 metamorphic rocks of the Government of Olenez. 

 He also did much geological surveying in the 

 Caucasus in connection with projected railways. 

 His interests gradually widened, and in 1882 he 

 published a volume (unfortunately in the Russian 

 language) on man in the Stone Age round Lake 

 Ladoga. He had much success as a teacher, and 

 among other researches which he encouraged may 

 be particularly mentioned those of his pupil, the 

 late Prof. Amalitsky, on the Permian deposits of 

 northern Russia. The Permian theriodont reptile 

 Inostransevia commemorates his name. 



We regret to announce the death, on June 19, of 

 Dr. F. A. Tarleton, senior fellow of Trinity College, 

 Dublin, a former professor of natural philosophy, 

 and president in 1906 of the Royal Irish .Academy. 



