JuUC 2, 1881] 



NATURE 



119 



brilliance of that group by the higher temperature of the dis- 

 charge in the denser gas, while the other lines of m.agnesium 

 fade, and even the hydrogen lines C and F are invisible. This 

 disappearance of the hydrogen lines they ascribe to the large 

 quantity of magiieiium carried over in the spark. When a 

 Leyden jar is now connected with the coil the fluted spectrum 

 continues bright for some time, but gradually fades as the con- 

 tinuance of the high temperature sparks decomposes the com- 

 pound. In nitrogen the flutings are only seen at first, probably 

 from hydrogen occluded, as is usually the case, in the magnesium, 

 and disappear when the pressure is increased, and cannot he made 

 to re-appear either by reducing the pressure or varying the 

 discharge. In carbonic oxide the behaviour is similar. The 

 authors conclude that the production of this spectrum is depen- 

 dent on a combination of the two elements, and is not merely a 

 matter of temperature. They describe this spectrum as consist- 

 ing of three parts, a group of three sets of flutings in the yellow 

 commencing at about the wave-lengths 5^'8> 55^^' 55'3 ! ^ 

 group of Iwo sets of flutings in the green commencing at about 

 w.l. 5210, and close to b ; and a group of two blue bands with 

 their less refrangible edges at about w.l. 4849 and 4803 respec- 

 tively. The authors differ from Ciamician, who has figured this 

 spectrum, in regard to the number of flutings in the green and 

 blue. This spectrum can be well seen when sparks are taken 

 from a solution of magnesium chloride in a tube full of 

 hydrogen. 



After simplifying the spectrum of magnesium by separating 

 that of magnesium hydrogen, and supposing the triplets to be 

 harmonically related, and perhaps some of the single lines 

 similarly related, there are still a greater variety of vibrations 

 than any very simply constituted particle could be expected to 

 be capable of as>uming. 



Linnean Society — Anniversary Meeting, May 24. — Prof 

 AUman, LL.D., F.R.S., president, in the chair. — There was 

 a very numerous attendance of the Fellows. — The Treasurer 

 (Mr. Frederick Currey) read his Annual Report, stating thai 

 financially the Society continued prosperous. The invested 

 capital at the present date is 3868/. 41. 6(1., the sum of 140/. 

 derived from Fellows' life compositions during the past twelve- 

 month having been invested in consols. The balance at the 

 bankers at the end of the financial year (April 30) was 532/. 

 \Qd., and at the] bankers' and on hand at this date (May 24) 

 604/. 15.?. \od. The annual contributions amounted to 928/. 4^., 

 and sales of publications 230/. 191. "jcl. ; there was an increase 

 in the admission fees, and decrease in compositions. 104/. Si. 31/. 

 had been expended on the purchase of books for the library, and 

 48/. IS. lid. towards bookbinding and stationery ; 765/. l8f. 2d. 

 had been spent on the Society's publications. A handsome 

 donation of 50/. had been made by Mr. G. Bentham. — The 

 Secretary (Mr. B. Daydon Jackson) then read his Report. Smce 

 the last anniversary eleven Fellows of the Society had died and 

 four had withdrawn. Against this thirty-seven new Fellows had 

 been elected, besides one Foreign Member and one Associate. 

 Daring the past year there had been received as donations to the 

 library 106 volumes and 125 pamphlets and separate impressions 

 of memoirs; from the vari jus scientific Societies there had also 

 been received in exchange ninety-six volumes and 24S detached 

 parts of publications, besides twenty-three volumes of donations 

 from the editors of independent periodicals. There had been 

 purchased 90 volumes of importance, among these 63 serials, 

 equal to 10 volumes, the total additions to the library therefore 

 being 315 volumes and 373 separate parts. Mr. Kippist had 

 presented framed water-colour sketches of Dr. Robert Brown's 

 birthplace, London residence, and Sir J. Banks's library. The 

 Society's collections and herbaria had been duly examined and 

 reported on to the Council as in good condition. After a 

 service of fifty years Mr. Kippist had resigned his position as 

 librarian to the Society, and the Council, in acknowledgment 

 thereof had granted him a retiring pension. — Mr. Baker, 

 in the name of Mr. J. W. Miers, then presented to the 

 Society a portrait of his father, the late John Miers, as 

 a memento of his connection therewith, and Prof. Allen 

 Thomson as representative of a small committee also presented 

 the portrait of Prof. St. George Mivart, late Zoological Secre- 

 tary, to the Society. — Prof. AUman then delivered his anniver- 

 sary address, the subject chosen being '-Recent Advances in 

 our Knowledge of the Development of Ctenophora.'' — The 

 Secretary afterwards read obituary notices of the several 

 Fellows that had died during the year, making special men- 

 tion of the life and labours of Mr. G. R. Alston, the late 



lamented Zoological Secretary, Mr. John Gould, the ornitho- 

 logist, Mr. Gerard Krefft, of Sydney, Dr. J. Lauder Lindsay, 

 and Mr. R. A. Pryor, of Herts. — The scrutineers having 

 examined the ballot, then reported that Mr. Alfred W. Bennett, 

 Mr. Francis Darwin, Prof. E. R. Lankester, Sir John Lubbock, 

 and Mr. Geo. J. Romanes had been elected into the Council in 

 the room of E. R. Alston (deceased). Dr. T. Boycott, Prof. M. 

 Foster, Dr. J. Gwyn Jeffreys, and Prof. St. George J. Mivart, 

 who retired ; and for ofiicers Sir John Lubbock was elected 

 president, Mr. F. Currey, re-elected Treasurer, Mr. B. Daydon 

 Jackson, re-elected Botanical Secretary, and Mr. G. J. Romanes 

 was elected Zoological Secretary. 



Zoological Society, May 17.— Dr. A. Giinther, F.R.S., 

 vice-president, in the chair. — Mr. Sclater exhibited and made 

 remarks on examples of four parrots of the genus Chrysoiis 

 from various islands of the Lesser Antilles. — A communication 

 was read from Mr. Carl Bock, in which he gave an account of 

 the land- and fresh-water shells collected in the highlands of 

 Padang, Sumatra, and in the eastern and southern parts of 

 Borneo during his travels in those districts. Eight new species 

 were described. — A communication was read from Mr. G. B. 

 Sowerby, jun., containing descriptions of eight new species of 

 shells from various localities. — Mr. W. A. Forbes read a paper 

 on the anatomy and systematic position of the Jacanas (Parridiv), 

 which he showed were in no degree related to the rails, but form 

 a separate group, to be placed amongst the jilovers and allied 

 birds (Limicoltc). The author also called attention to the peculiar 

 form of the radius in the genus ]\htopiduts, which is not deve- 

 loped in the other genera of this group. — A communication was 

 read from Mr. L. Taczanowski, C.M.Z.S., containing the 

 description of a new species of weasel from Peru, proposed to 

 be called Muslela Jehkii, after its discoverer. — A communication 

 was read from Mr. W. F. Kirby, containing a description of the 

 hymenopterous insects collected in Socotra by Prof. Bayley 

 Balfour. Of these two were apparently new to science. — A 

 communication was read from Mr. Francis Day, F.Z. S., 

 containing remarks on the range of Apogon ElUoti. 



Royal Microscopical Society, May 11. — Prof. P. Martin 

 Duncan, F.R.S., president, in the chair. — Ten new Fellows were 

 elected and nominated. — Amongst the objects exhibited were 

 Seibert's polarising microscope, Nachet's binocular dissecting 

 microscope, Verick's skin microscope, Houston's botanical micro- 

 scope, embryological sections from the Naples Zoological Station, 

 &c. — Papers and notes were read on a new and remarkable annelid 

 (Mr. Stewart) ; the markings of diatoms (Dr. Matthews, Mr. J. 

 Deby and Count Castracane) ; a new species of Hydrosera 

 WalUcli (Dr. Stolterforth) ; and improvements in illumination 

 (Mr. J. Smith) ; also a note by Prof. Abbe on the conditions of 

 micro-stereoscopic vision, with special reference to the fact that 

 the lineal amplification of an object in depth is equal to the 

 square of the lineal amplification in breadth, reduced, however, 

 in proportion to the refractive index of the medium in which 

 the object is : thus an object under a power of 100 times would 

 be magnified ro,ooo times (lineal) in depth if in air, 7500 times if 

 in water, and 56oo if in oil or balsam. 



Edinburgh 

 Royal Society, April 4.— Prof. Fleeming Jenkin, vice- 

 president, in the chair. — In the absence of the author. Prof. 

 AUeyne Nicholson read a descriptive note by Dr. Carmichael 

 Mcintosh on the Phoronis, one of the specimens obtained in the 

 dredging operations of the Challenger. This Annelid was ai 

 special interest as indicating in several particulars close similarity 

 to certain well-known Calenterates. — Dr. R. H. Traquair read 

 a paper on additional researches on the structure of the Palno- 

 niscidcT and Platysomidtr. The more that the fossil remains of 

 these families w^ere studied the more difiicult did it become to 

 clearly differentiate them from each other ; and from his later 

 researches Dr. Traquair had been obliged to adopt a wider 

 definition of Palc^oniscidiZ than he had formerly employed. 

 Hence it appeared that the criticism that had been urged against 

 his former papers, viz., that he had not shown sufficient ground 

 for their separation as two distinct families, could still be urged 

 with even greater reason ; but this, according to the doctrme of 

 descent, was a natural consequence of increased information. 

 Certain of the specimens he had examined, though retaining the 

 most essential characteristics of either family, as the case 

 might be, possessed modifications of structure which were 

 ordinarily typical of the other. The evidence was that the 



