Feb. iS, I 



NA TURE 



383 



minute fragments of minerals, by balancing in a liquid of a 

 specific gravity adiustable to that of the mineral, fails altogether 



(a) when the substance has a specific gravity over 4'5 about ; 



(b) Vfhen it is of a porous nature. The author deals with mine- 

 rals having a specific gravity above that of Thulet's solution, or 

 of a porous nature, by embedding a known weight of the mineral 

 in a known weight of paraffin of known specific gravity, and 

 then determining the specific gravity of the mixed bodies by 

 balancing in a solution of low density. From these data the 

 required specific gravity is calculable. Several experiments 

 carried out on fragments of heavy or dendritic minerals ranging 

 in quantity from 12 to 35 milligrames were quoted. These gave 

 results concordant with recorded densities, and, where carried 

 out on pieces removed from the same hand specimen, were 

 uniformly consistent. — Celestial phenomena explicable by 

 meteors, by W. H. S. IVIonck, IVI.A. 



Section of Natural Science.— J. P. O'Reill)', C.E., in the 

 chair. — Notes on the energy of the Ischia earthquakes of 1S81 

 and 18S3, by Rev. Dr. Haughton, F.R.S.— Dr. Haughton also 

 communicated an extract from a letter from a lady in India, 

 respecting the fall of a meteoric stone at Roorkee. — Note on 

 Edwardsia timida (Quatr.), by G. T. Dixon, M.A. The speci- 

 men was found atlMalahide, Co. Dublin. This is the first record 

 of the occurrence of this species in the British Isles. 



Sydney 

 Linnean Society of New South Wales, November 25, 

 1885.— W. J. Stephens, F.G.S., President, in the chair.— The 

 following papers were read : — A list of the Trogositida; of 

 Austraha, with notes and descriptions of new species, by A. 

 Sidney Olliff, F. E.S., Assistant Zoologist, Australian Museum. 

 — Notes from the Australian IVIuseum— a new butterfly of the 

 family Lyca;nida;, from the Blue Mountains, by A. Sidney Olliff, 

 F.E.S., Assistant Zoologist, .ALUStralian Museum. — On a remark- 

 able fish, from Lord Howe Island, by William Macleay, F.L.S., 

 &c. Under the name of Ctenodax 'oilkinsoni, Mr. Macleay 

 described a fish picked up on the beach at Lord Howe Island, 

 and made some remarks on its probable affinities. He considers 

 it not referable to any known family. — Recent changes in the 

 forest flora of the interior of New South Wales, by R. von 

 Lendenfeld, Ph.D. Based on observations made by Mr. Forest 

 Ranger Ridston and others, and on his own experience in the 

 Nymagee-Condobolin district, the author gives an account of 

 the rapid spreading of the pine {Frcmla robusta) within the la^t 

 twenty years. A table giving averages of the rainfall, the 

 spread of the pine and of the hee.i\e Diodoxus eiyHiniriis, White, 

 which in its larval stage destroys the young pine-trees, accom- 

 panies the paper. — The Australian freshwater Rhizopods, Part I., 

 by R. von Lendenfeld, Ph.D. This paper is the first of an 

 intended series in which the Australian Protozoa belonging to 

 the groups Rhizopoda and Heliozoa are to be registered, and 

 the new species described. In this paper six species are men- 

 tioned, two are new. It is a most remarkable fact that the 

 common and well-known European forms are all apparently 

 found in equal abundance in Australian water.:. The new 

 sjiiecies are very similar to European ones, and do not present 

 any marked peculiarities. It does not appear likely that there 

 were no Rhizopods in Australian creeks before the advent of 

 Europeans, and so it cannot be assumed that all these Australian 

 species have been imported. As they cannot travel over the 

 oceans dividing Australia from other continents, it rnust be 

 assumed that they are unch.anged descendants of the Rhizopods 

 of that geological period, in which Australia was not isolated. 

 The absence of forms peculiar to Australia speaks strongly 

 against any recent spontaneous generation. — An Alga forming a 

 pseudomorph of a siliceous sponge, by R. von Lendenfeld, 

 Ph.D. — Onchidiiim chameleon, sp. nov., and the structure of 

 the dorsal skin of this and other Onchidia, by R. von Lendenfeld, 

 Ph.D., and John Brazier, C.M.Z S. — Observations on some 

 Australian Polychoeta, by W. A. Haswell, M.A., B.Sc, &c. — 

 Descriptions of two new fishes from Port Jackson, by E. P. 

 Ramsay, F.R.S.E, &c., and J. Douglas-Ogilby, Australian 

 Museum. — On some remarkable crystals of siderite, by F. Ratte, 

 Eng., Arts and Manufactures (Paris). 



Paris 

 Academy of Sciences, February 8. — M. Jurien de la 

 Graviere, President, in the chair. — Discourses on the occa- 

 sion of unveiling the statue erected in front of the College 

 de France to the memory of Claude Bernard, on February 4, 



by MM. Paul Bert, Eerthelot, Fremy, and Chauvcau. '. The 

 statue, which is cast in bronze, is the work of M. Guillaume, 

 Member of the Institute. — Farewell address of M. Paul Bert 

 on his departure to Tonquin, where he has recently been ap- 

 pointed Civil Administrator. In the course of his remarks the 

 speaker expressed a hope that the young naturalists of the West 

 would begin to turn their attention to the Far East, and teach 

 the learned classes of those regions more fully to appreciate the 

 superiority of European science. " I rely on them," he added^ 

 "to increase our moral influence, and also to enlarge our know- 

 ledge of that region, in many places still unexplored, to study 

 its resources, and prepare the way for the introduction of the 

 great European industries. They will thus at once promote the 

 interests of science and of France, a task enviable beyond all 

 others." — Remarks on the celebration of the centenary of Arago's 

 birth, on February 26th prox., by M. Mouchez. It was 

 stated by the speaker that the celebration would t.ake the form 

 of a public ceremony in the presence of the various deputations, 

 during which would be crowned the bust of Arago, occupying 

 the site on the Boulevard Arago, where a monumental statue is 

 subsequently to be raised to the great astronomer by public 

 subscription. The proceedings will close with a subscriptinn 

 banquet at the Hotel de Ville, to which will lie invited the 

 members of the Arago family. — Note on celestial photography, 

 by M. Mouchez. Amongst the stellar photographs already 

 obtained at the Paris Observatory, was [one of the nebula 

 near the star Maia in the Pleiades, which had never 

 before been seen with the best glasses. But M. Struve 

 now telegraphs to the author that he has just detected this 

 nebula with the new large equatorial of o'So m., recently 

 set up in the Pulkova Observatory. It was added that Dom 

 Pedro, Emperor of Brazil, had instructed M. Cruls, Director of 

 the Rio de Janeiro Observatory, to prepare a photographic 

 apparatus sim'ilar to that now in use in Paris, for the purpose of 

 co-operating in the general project of photograjjhing the starry 

 regions, already begun with such unexpected success at the 

 Paris Observatory. — Determination of the elements of re- 

 fraction, two diagrams, by M. Lcewy. It is shown that, 

 in spite of all the rotatory movements of the double 

 min-or, the fundamental condition for determining the con- 

 stant of refraction is always fulfilled. This principle rests 

 on the geometrical property that the projection of the 

 distance of two images on the trace of the plane of reflection 

 remains inv.ariable and always equ.al to the distance r'f' relative 

 to the epoch when the two stars and their two reflected images 

 are found comprised in the same plane. — On some hyper- 

 elliptical formulas, by M. Brioschi. — Note on the first botanical 

 collections that have reached the Paris Natural History Museum 

 from Tonquin, by M. Ed. Bureau. This first collection, carefiiUy 

 prepared by M. Balansa, is confined exclusively to the neigh- 

 bourhood of Hai-Phong and of Quang-Yen ; but it gives a com- 

 plete picture of the flora of these districts.— Remarks on the 

 admission of patients suffering from pulmonary tuberculosis into 

 the public hospitals, with a view of determining how far this 

 disease is contagious, by M. E. Leudet. The elements that 

 have served to offer a solution of this question are the records of 

 16,094 adult patients of both sexes treated in one of the wards 

 of the Rouen Hotel-Dieu during the thirty-one years from 1854 

 to 1885. The author concludes that the propagation of pul- 

 monary tuberculosis by contagion in hospitals has not been 

 demonstrated, or that it is at least very restricted.— Observations 

 on Fabry's comet made at the equatorials of the Bordeaux Ob- 

 servatory, by MM. G. Rayet and Courty. — Equatorial observa- 

 tions on Barnard's comet, made at the Bordeaux Observatory, by 

 M. F. Courty.— Observation of Brooks's comet made with the 

 14-inch equatorial of the Bordeaux Observatory, by MM. G. 

 Rayet and Courty.— On the shower of shooting-stars observed 

 on November 27, 1885, at the Zi-ka-wei Observatory near 

 Shanghai, China, by Pere Marc Dechevrens. The meteoric 

 display is described as less imposing than that of November 27, 

 1S72. The stars appear to have swept by at the rate of about 

 a hundred every 15 minutes. Notwithstanding the moonlight 

 a few were still seen so late as 4 a.m. the following morning 

 —On a new s}Stam of projection of the sphere suggested by 

 an inquiry into the means of representing the elliptical functions 

 geometrically, by M. Guyon.— Note on Ivory's theorem and on 

 some theorems in connection with the homofocal surfaces ot 

 the second order, by M. A. Mannheim.— Researches on the 

 groups of finite order contained in the group of the linear substi- 

 tutions of contact, by M. Autonne.— Note on a new process for 



