54 



NA TURE 



[December 17, 1891 



proportional numbers under all circumstances. A change 

 in the shape of the molecules, or an augmentation of 

 their diameters, will affect the first number in a much 

 greater proportion than the second. But, as I have 

 shown, the equation of Van der Waals holds good, inde- 

 pendently of this assumption. 



D. T. KoRTEWEG. 

 Amsterdam, November 4. 



THE BIRD-GALLER V IN THE BRITISH 

 MUSEUM. 



A LONG-NEEDED and much-wished-for reform, 

 ■^*- to which the attention of naturalists should be 

 specially invited, has been commenced in the Bird- 

 gallery of the British Museum. Under the old 7'egime 

 at Bloomsbury, the rule was, as it is even now in most of 

 the Continental Museums, that every specimen should be 

 stuffed, and exhibited in the public gallery. The natural, 

 if not the necessary, consequence of such a rule is that, 

 as time progresses, the shelves become crowded with 

 badly mounted specimens, which are very unpleasing to 

 the general observer, and most inconvenient to the 

 scientific worker. 



In the British Museum, however, the idea of mounting 

 every specimen has been long ago abandoned. The 

 main collection for scientific work is, we need hardly 

 say, that of skins. These are arranged in cabinets, in 

 numbers which it would be impossible to find space for if 

 " mounted." When thus disposed of they are much more 

 easy to find, and more convenient for examination, than 

 "mounted" specimens. Though it may be sometimes 

 necessary to refer to the Bird-gallery, the working orni- 

 thologist of this country, as a rule, uses only the skin 

 collection. 



This being so, the question arises as to what is the best 

 way of making the Bird-gallery useful, and attractive to 

 the general public. As to this there can be no question, 

 it appears, that the Bird-gallery should be fitted up as an 

 " Index Museum," and should contain a series of the 

 principal types of bird-life arranged in systematic order 

 from the highest to the lowest. Every family should be 

 placed in a separate case, in its proper position between 

 the two groups to which it is most nearly allied. In 

 each family a series of well-mounted specimens should 

 illustrate the principal sub-families and genera, and the 

 male and female and other plumage of the leading species. 

 Nests and eggs should be added to show the mode of 

 nidification, and maps to show the areas of distribution. 

 Diagrams and preparations of particular structures 

 should be placed at the head of each group, to exhibit 

 its special peculiarities ; and finally, every specimen and 

 diagram should be clearly labelled and explained. It will 

 readily be understood that a Bird-gallery filled up in this 

 way would be a most instructive object, and much more 

 useful and attractive than the crowded rows of uniformly- 

 set-up specimens that are offered to view in most public 

 Museums. Some such plan as this, we take it, is what 

 the authorities of the British Museum have now in 

 view. 



For a commencement, the family of Woodpeckers has 

 been selected, and a case devoted to its illustration has 

 been fitted up. A series of well-mounted specimens 

 shows the leading forms of the group, and diagrams, 

 preparations, and maps exhibit its principal peculiarities 

 and the distribution of the species. 



This is at present only the beginning of a very 

 important change of plan. But there can be no question 

 that if the scheme is carried out, and the whole Bird- 

 gallery is treated in a similar way, an admirable reform 

 will have been effected. 



NO. 



I I 55, VOL. 45] 



THE OCTOBER ERUPTION NORTH-WEST OF 



PANTELLkRIA. 

 COME time after the news arrived in this country of 

 •^ the volcanic outburst in the neighbourhood of Pan- 

 telleria, my friend Mr. Geiard Butler, F.G.S., undertook 

 to visit the island, and to investigate the interesting 

 phenomena that were being exhibited there. Mr. Butlei 

 has now returned, having made a large collection of 

 specimens of rocks and minerals, and I trust that before 

 long we shall have fuller information concerning this 

 remarkable district. The following short note embodies 

 the general results of his inquiries concerning the recent 

 eruptions ; but telegrams received since his return state 

 that renewed outbursts have led to the formation of an 

 island at the spot, and mariners have been warned to 

 avoid it. John W. Judd. 



Royal College of Science, London, December 14. 



In Nature of December 3 (p. 120), a short sketch is 

 given of a paper by M. Ricco on the above, which those 

 interested in the subject may read in the Comptes rendus 

 for November 25. 



It may be worth while for one who visited Pantelleria 

 soon after the eruption to point out that there appears to 

 be no foundation for the idea conveyed by many Eng- 

 lish accounts and by the words " island, " " erupted 

 island," in Nature {loc. cit.), that an island comparable 

 to Graham's Island was formed. 



It seems that by a submarine eruption which, after 

 prefatory earthquakes between October 14 and 17, was 

 first observed on the latter day, about 5 kilometres to the 

 north-west of Pantelleria, a narrow band of floating 

 bombs, extending for about a kilometre in a north-east 

 and south-west direction, was produced. 



The persistence during the eruption of this linear band 

 may perhaps indicate the line of fracture of the sea 

 bottom. 



There appears to have been always deep water at the 

 scene of eruption. Rieco tells us that soundings at the 

 middle and ends of the floating shoal of bombs found no 

 bottom at 320 metres. 



The brittle cindery bombs readily broke up, giving vent 

 to the superheated steam tbey contained ; when, or upon 

 their becoming otherwise waterlogged, they sank, so that, 

 on October 26, soon after the eruptive action ceased, all 

 traces of it had disappeared in deep water. 



G. W. Butler. 



NOTES. 

 We regret to have to record the death of Prof. Stas, the 

 eminent Belgian chemist. He died at the age of seventy-eight. 



At last Thursday's meeting of the Royal Society, the Presi- 

 dent read from the chair a letter from Prof. Dewar, which had 

 been put into his hand as he entered the meeting-room, in 

 which Prof. Dewar stated that he had at 3 p.m. that afternoon 

 " placed a quantity of liquid oxygen in the state of rapid 

 ebullition in air (and therefore at a temperature of —181" C.) 

 between the poles of the historic Faraday magnet in a cup- 

 shaped piece of rock salt (which is not moistened by liquid 

 oxygen and therefore keeps it in the spheroidal state)," and to 

 his surprise, Prof. Dewar saw the liquid oxygen, as soon as the 

 magnet was stimulated, "suddenly leap up to the poles and 

 remain there permanently attracted until it evaporated." 



According to information sent to Berlin, Emin Pasha and 

 Dr. Stuhlmann, travelling in the region between Lakes Victoria, 

 Tanganyika, and Albert Edward, have discovered what they take 

 to be the ultimate source of the Nile. This is a river called 

 Kifu, which is supposed to have its sources in the Uhha country, 

 lying to the east of the northern part of Lake Tanganyika,. 



