April 14, 1898] 



NATURE 



575 



and Betchworth ; and between that date and the middle of July 

 the country from Aylesbury to Cuckfield will be systematically 

 examined by the class so as to draw a section over the trough of 

 the Thames basin, and see the deposits to the north and south 

 of London, which underlie the rocks associated with the chalk. 

 The class has been organised and carried on by Prof. H. G. 

 Seeley, F.R.S., for the past twelve years, without difficulty of 

 any kind, and without assistance. It was established as a class 

 to show that systematic instruction in geology could be given in 

 the open country, and the example it affords must tend to bring 

 about more practical teaching in the matter of field-work. 

 When the class began there was very little of such teaching any- 

 where, but the value of individual observation is now accepted 

 as a canon of scientific education, and the success of Prof. 

 Seeley's work should encourage educationists in their endeavour 

 to get the fact-knowledge entirely substituted for the word-know- 

 ledge of books. 



SOCIETIES AND ACADEMIES 

 Dublin, 



Royal Dublin Society, March i6. — Proi. G. F. Fitzgerald, 

 F.R.S., in the chair.— Prof. J. Joly, F.R.S., and Dr. H. H. 

 Dixon read a paper on the distribution of coccoliths and on 

 some microscopic organisms found in Dublin and Killiney Bays. 

 Coccoliths have been found by the authors on the Irish coast at 

 Sligo, Slyne Head, Dingle, Waterville, and along the coast of 

 south Co. Dublin, and on the south coast of England at Wey- 

 mouth. Samples of water from Loch Inver and Portstuart did 

 not afford any examples. Coccoliths were also found in the 

 mud obtained in the Severn and Liffey beds. In the paper are 

 also described a new marine Difflugia and organisms from 

 Killiney Bay resembling Ehrenberg's Pyxidicula and Xanthidia 

 from the chalk. — A paper by Prof. W. Noel Hartley, F.R.S., 

 and Mr. Hugh Ramage was then read by the former, the subject 

 being a determination of the wave-lengths of the principal lines 

 in the spectrum of gallium, showing their identity with two lines 

 in the solar spectrum. The authors have found gallium to be a 

 very widely distributed element in the earth, and to be present 

 also in meteoric bodies. It became natural to inquire if it is 

 present in the sun. The wave-lengths of the two principal 

 lines have not previously been determined by a grating spectro- 

 graph, and the authors availed themselves of the kind offer of 

 Dr. Adeney to allow them to photograph spectra of gallium with 

 the 21^ feet radius grating spectrograph in the Physical Labora- 

 tory of the Royal University of Ireland. The two principal 

 lines were photographed as bright and reversed lines in arc 

 spectra, and as bright lines in the spark spectrum of a solution 

 of gallium chloride. In these and in the oxyhydrogen spectrum 

 of gallium compounds the less refrangible line is always stronger 

 than the other. The wave-lengths of the two lines, determined 

 by interpx)lation from adjacent iron lines, are found to be 

 4172*215 and 4033'i25. In Rowland's map of the solar spec- 

 trum there are two lines probably identical with these, namely: — 



4i72'2ii. Source: Aluminium. Intensity: i, 

 and 4033* 1 12. Not identified. ,, oo. 



It is pointed out that gallium is present in every bauxite and 

 shale examined by the authors, and also in metallic aluminium, 

 and no doubt the line 4172211 in the spectrum of aluminium is 

 really a gallium line. From the very close agreement of the 

 wave-lengths, from the relative intensities of the lines as shown 

 above, and from the evidence of the wide distribution of the 

 element, it seems certain that the two gallium lines are identical 

 with the two lines above mentioned in the solar spectrum, and 

 there are no other lines so close to these. The evidence is dis- 

 cussed at length in the paper, as also is the effect of the presence 

 of elements upon the spectra of other elements. — Prof. J. P. 

 O'Reilly read a paper on the occurrence of anatase and brookite 

 in the quartzites of Shankill, Co. Dublin. He explained that 

 the minerals were found in a mass of yellow earth, met with by 

 the quarrymen in 1888, and had only lately been examined. 

 The peculiarity of the anatase was its approximation in compo- 

 sition to the clay or mineral analysed by Eakins as mentioned by 

 Dana in his "System of Mineralogy," edition of 1892, p. 716, 

 while presenting the crystalline form of anatase, thus allowing 

 of the presumption that the clay analysed by Eakins and called 

 by him " Xanthitane," was probably the product of decomposi- 

 tion of an anatase having much the same composition as the 

 mineral found at Shankill. 



NO. 1485, VOL. 57] 



Edinburgh. 

 Royal Society, March 21. — Lord Kelvin, President, in 

 the chair. — Lord Kelvin, in a paper on thermodynamics, 

 deduced from motivity, fulfilled a promise made twenty-one 

 years ago to the Society. After referring to the somewhat mis- 

 leading phrase, the mechanical equivalent of heat, and pointing 

 out the necessity of having a single word to express the avail- 

 ability of heat for transformation into useful work, he proceeded 

 to show that the whole of thermodynamics was contained in the 

 two equations 



de =JNrf/-t-2(Prf^-l- JMrf^) 



dm =}*^^dt + 2(p -I- -{^yidg) 



where e is the energy, vi the motivity, t the temperature of 

 any part of the system, T the lowest temperature in the 

 system, g any coordinate, P the corresponding force, and 

 N, M specific heats. The usual equations are at once 

 deduced by treating de, dm as complete differentials. — Dr. Gait, 

 of Glasgow University, communicated a paper on the micro- 

 scopical appearances of the grains in the more commonly occur- 

 ring starches. The paper was full of detail, and was illustrated 

 by numerous original photographs and lantern slides. In a 

 paper on methods of mapping rainfall, Mr. A. J. Herbertson 

 described a simple graphical method for taking into account the 

 varying lengths of periods of observation of rainfall at different 

 parts of the globe. The mean rainfall values were inserted on 

 the maps in different coloured inks, according to the length of 

 period of observation. The general trend of the isohyets could 

 be attained by comparing similarly coloured means, and the final 

 positions of the lines fixed by the values at the stations with the 

 most extended records. The variableness in the length of the 

 month is allowed for by drawing isohyetal lines, whose actual 

 values are the nominal values multiplied by the days in the cor- 

 responding month, and divided by one-twelfth of a year ex- 

 pressed in days. In a second paper, on the normal rainfall 

 of India and the abnormalities in 1896, Mr. Herbertson 

 showed maps on the mean annual and monthly rainfall of India, 

 based on the means published in the rainfall data for 1895, ^"^^ 

 those in the annual summary for i8q6. 



Royal Physical Society, March 16.— Mr. B. N. Peach, 

 President, in the chair. — Papers were read by Mr. W. S. Bruce, 

 of the Jackson- Harmsworth expedition, and Mr. William Eagle 

 Clark, on the mammals and birds of Franz Josef Land. Mr. 

 Bruce, who spent fifteen months on Franz Josef Land in 1896-97, 

 explained that the number of species, exclusive of mammals and 

 birds, he then obtained exceeded that of any previous Arctic ex- 

 pedition, he having secured 236 against 216 to the credit of the 

 United States expedition of 1881-83. He had at least doubled the 

 number of species known to Franz Josef Land. He had found 

 ancient reindeer horns, though there were no reindeer at present 

 in the Land. Among the specimens he exhibited were the bones 

 of whales and walruses found on raised beaches with an elevation 

 of from 50 to 80 feet, plainly indicating their great age ; while 

 one specimen — the scapula of a walrus — was found at a height 

 of 336 feet. The chief point of interest in Mr. Clark's part of 

 the subject, which was restricted to birds, was the findiiig of 

 several new species — Bonaparte's sandpiper, purple sandpiper, 

 and the shore lark. The first mentioned of these, Mr. Clark said, 

 was not only a new and remarkable addition to the ornis of 

 Franz Josef Land, but it was the first authentic example of this 

 American species that had been obtained in Europe elsewhere 

 than in the British Isles. Another subject of interest in the 

 paper was the description of a newly-found nesting-place of the 

 ivory gull. This was at Cape Mary Harmsworth, on what was 

 considered to be one of the largest pieces of bare ground in 

 Franz Josef Land. Of the twenty-two species of birds which 

 formed the avifauna of Franz Josef Land, only ten had been 

 found breeding, though several more undoubtedly nested there, 

 while several, again, were mere stragglers. 

 Paris. 



Academy of Sciences, April 4. — M. Wolf in the chair. — 

 On a doctrinal point in the theory of quadratic forms, by M. 

 de Jonquieres. — Contribution to the study of Zeeman's pheno- 

 menon, by MM. Henri Becquerel and H. Deslandres. An 

 account of some experiments on the influence of a magnetic 

 field upon the periods of vibration of the radiations emitted by 

 incandescent vapours. — Movements of the sensitive plant when 

 grown in water, by M. Gaston Bonnier. The author has suc- 

 ceeded in cultivating Mimosa pudica completely immersed in 



