136 



NATURE 



[June 18, 1874 



petition with new varieties of silkworms, which are described as 

 possessingmany qualities which will render tliem a most useful addi- 

 tion to the various silkworms now under cultivation. — The Society 

 has been successful in securing two specimens of a fish called the 

 Gourami, from Singapore ; attempts have been made to procure 

 some of these fish for introduction into this country, but they have 

 as yet been unsuccessful. The introduction of the D'wspyros, a 

 Chinese fruit-tree, is recommended, and attempts are being 

 made to acclimatise it. — M. Millet is endeavouring to secure 

 some means of foretelling the approach of cold weather in the 

 spring months, and asks for any observations on the point which 

 others may have made. — An interesting paper by M. J. Lapru, 

 on the Italian bee, points out the superior qualities of that insect, 

 and suggests its more general cultivation. 



Jahrbucli der kais. k'on. geologisclun Reichsanslalt. Band .xxiii. 

 Nos. 3 and 4. — The first paper in No. 3 is by Dr. O. Feistmantel 

 On the relation of the Bohemian carboniferous formation to the 

 permian. The pala;ontological and physical evidence enables 

 the author to arrange these formations as follows : — I. Permian 

 formations, a Upper grouo (with two stages) consisting of red 

 sandstone with bituminous shales, containmg animal remains, 

 and red shales with various plant-remains ; marl, limestone, and 

 calcareous shales with abundant animal remains. /' Lower 

 group, or permanent coal-bearing group, containing coal-seams, 

 generally accompanied with bitu.-ninous shales. The beds yield 

 permian animal remains, and a rich flora almost entirely non- 

 carboniferous. Red sandstones with aiiracaiiies are also in- 

 cluded in the group. II. Carboniferous formation: grey sand- 

 stones and carboniferous shales ; coal-seams without accompanying 

 bituminous shales, and without a fauna which can be brought 

 into relation or connection with the permian. The flora shows 

 no admixture of permian types. — In the second article I. Niedz- 

 wiedzki gives some account of the basalt rocks met with in the 

 carboniferous basin near Moravian Ostraw ; and the other papers 

 in the number are On the occurrence of Tertiary (or mations in the 

 upper region of the Mantza valley, that is, between the Balkan 

 and the Rhodope mountains in Rumili ; and Contributions to 

 the geology of the Fruska Gora in Syrmia. — There are only 

 two geological papers in No. 4, the first of which is a very long 

 contribution, by F. Posepny, On the lead and cadmia veins of 

 Raibl in Carinthia, which is well illustrated with coloured litho- 

 graphs, showing sections of various vein-stores, ores, minerals, 

 &c., and a map of the workings, &c. — The second paper is by 

 Dr. Mojsisovics, On son>e triassic fossils ftom the South Alps ; 

 two plates accompany the paper. — Among the " Mineralogical 

 Communications," so carefully edited by Dr. Tschermak, there is 

 one paper of somewhat general interest. An outline of a mecha- 

 nical theory of the laws of crystallisation, by Dr. J- Hirschwald. 

 Verhandlungen dc-s iiatuihist. Vereuis d. pr. Rheiiilaiide u. 

 WestphaUns, zg/fr 11. 30/cr yahrsa>!g.—T:he: former of these 

 volumes contains, among other pap, rs, one On Vesuvius, by Von 

 Rath and Von Lasaulx ; On the structure of Trilobites, by Von 

 Koenen ; On the effect of extreme cold on plants, by Mohr ; On 

 Monas prodigosa, by Prof. Binz of Bonn; On the pupil of the 

 fox, by Troschel ; On benzyl-sulpho-cyanates, by Kekule ; and 

 others on technical points of medicine. In the latter we riiay 

 note Dr. Braun's description of the Upper Jura, with a geological 

 section ; Dr. Umber's measurements of the skulls of numerous 

 mamma'lia, in which he attempts to find a criterion of their in- 

 telligence in the propoition of the anterior to the posterior part 

 of the basis cranii (accovdiig to his results the Carnivora are 

 inferior to the Quadrumana; and Horses to Rodents and Marsu- 

 pials) ; two papers on the geological and palceontological features 

 of the cave at Balm : one by Rindfleisch On tubercular inflam- 

 mation ; and one by Kekule On allyl compounds. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, June 11,— Note on the alleged existence of 

 Remains of a Lemming in Cave-deposits of England, by Prof. 

 Owen, F.R.S. 



Note on the Absorption- Spectra of Potassmm and Sodmm 

 allow temperatures, by II. E. Roscoe, F.R.S., and Arthur 

 Schuster. 



In order to obtain the absorption-spectrum afforded by the 

 well-known green coloured jiotassium vapour, pieces of the clean 

 dry metal were sealed up in glass tubes filled with hydrogen, and 

 one of these was then placed in front of the slit of a large Stein- 



hill's spectroscope, furnished with two prisms having refracting 

 angles of 45° and 60'. Tlie magnifying power of tlie telescope 

 was 40, and was sufficient clearly to separate the D lines with 

 one prism. A continuous spectrum from a lime-light was used, 

 and that portion of a tube containing the bright metallic globule 

 of potassium was gently heated untU the green vapour made its 

 appearance. A complicated absorption spectrum was then seen, 

 a set of bands (a) in the red coming out first, whilst after a few 

 moments two other groups appeared on either side of the D 

 lines, the group ;3 (less refrangible) being not so dark as the 

 group 7. These bands are all shaded off to.vards the red, and 

 m general appearance resemble those of the iodine spectrum. 

 In order to assure ourselves that the bands are not caused by the 

 presence of a trace of an oxide, tubes were prepared in which 

 the metal was melted in hydrogen several times on successive 

 days until no further change in the bright character of the globule 

 could be perceived. On vapourising the metal, which had been 

 melted down to a clean portion of the tube, the bands were seen 

 as before, and came out even more clearly, the globule, after 

 heating, exhibiting a bright metallic surface. An analysis of the 

 potassmm used showed that it did not contain more than o'8 per 

 cent, of sodium, although, of course, the double line D was al- 

 ways plainly seen. 



In order to ascertain whether an alteration in the absorption- 

 spectrum of the metal takes place at a red heat, fragments of 

 potassium were placed in a red-hot iron tube, through which a 

 lapid current of pure hydrogen gas was passed, the ends of the 

 tube being closed by glass plates. The magnificent green colour 

 of the vapour was clearly seen at this temperature on looking 

 through the tube at a lime-light placed at the other end. Owing, 

 doubtless, to tl'e greater thickness or increased pressure of the 

 vapour, the bands seen by the previous metliod could not be 

 resolved by the sma'd spectroscope employed, the whole of the 

 red being absorbed, whilst a broad absorption-band in the 

 greenish yellow was seen o:cupying the place of the group 7. 



The positions 'of the bands obtained by the first method were 

 measured by means of a telescope and distant scale, and ttie 

 wave-lengths obtained by an interpolation curve, for which Will- 

 known an- lines were taken as references. The following numbers 

 give the wave-lengths of the most distinct, that is, the most re- 

 frangible edge uf each band. As the measurements had to be 

 quickly made owing to the rapid darkening of the glass by the 

 action of the metallic vapour, these numbers do not lay claim to 

 very great accuracy, but fairly represent the relative positions of 

 the band, and show that they do not always occur at regular 

 intervals, although they are pretty regularly spread over the field, 

 and all are shaded alike. 



Bands of potassium shaded off towards red. 

 tenth metre : — 



63"! 

 6300 

 6275) 

 6059, 



6033 



6012 > 



59SS 



5964^ 



The bright potassium lines in the red and violet were not seen 

 reversed, the intensity of the lime-light being too small at both 

 extremes to render an observation possible. 



In order to ascertain whether the vapour of sodium, which, 

 when seen in thin layers, appears nearly colourless, exhibits 

 similar absorption-bands, tubes containing the pure metal, which 

 had been prepared and preserved out of contact with any hydro- 

 carbon, were prepared, the metal being obtained free from oxide 

 and the absorption-spectrum being observed in the manner al- 

 ready described. As soon as the metal began to boil a series of 

 bands in the blue (Na7)made their appearance, and shortly 

 afterwards bands in the red and yellow (Na ct), stretching as far 

 as the D lines, came out. At this period of the experiment the 

 D lines widened, thus blotting out a series of fine bands occurring 

 in the orange (Na ,8), some of which could in consequence not 

 be mapped. All the bands of the sodium-spectrum shade off 

 like the potassium bands towards the red. 



When the vapour of sodium is examined in a red-hot iron 

 tube the colour of the lime-light as seen throuyh it is a dark blue. 

 As the sodium is swept away by the current of hydrogen passing 

 through the colour becomes lighter, ani the transmitted rays can 

 be analysed by the spectroscope. At first the whole red and 

 green and part of the blue is cut out entirely. 'I'he D lines are 



5949) 

 5930 1 1 

 5901 ) 



5S60 , 



SS42 

 5821 ■ 



5So2\ 

 5781^ 



Wave-length in 



5763 > 

 I 5745 



5732 



S7I2 



5700 / ' 

 ■ 5690 



5674 



5667 ) 



