212 



NA TURE 



{June 2%, 1883 



aurora flashes, though it does not seem to have been remarked. 

 My own observations have all been made with a very wide 

 slit, or, which comes practically to the same thing, with small 

 dispersion. This has been owing to the usual feebleness of the 

 greater part of the spectrum ; and many of the other observers 

 have for the same reason also used a wide slit. It may be useful 

 to explain the method by which most of my observations were 

 made, as it seems successful for perceiving the lines and general 

 character of I he spectrum, though not for measuring the posi- 

 tions. I have simply used one or two, or in some cases three 

 prisms, usually of Chance's dense flint glass, and for a slit, the 

 space between window-shutters nearly shut, or between two 

 planks placed against the window. I hold the prisms in my 

 hand on a simple stand, not always fixed, but so that they may 

 be easily moved with respect to each other and to the slit, so 

 varying the amount of dispersion. The best results are usually 

 obtained by holding them in the position of almost the greatest 

 deviation possible. Varying the deviation alters the focus. 

 If one plank or shutter is placed rather further forward than 

 the other, the apparent width of the slit is varied at will by 

 simply moving one's head to one side or the other. By these 

 means it is easy to observe all the different features of the 

 spectrum, which require different widths of the slit and degrees 

 of dispersion. A vacuum-tube or other light for comparison 

 may be placed behind the slit, though it is obvious that with 

 small dispersion accurate comparisons cannot be made. 



I have made some observations with a Browning's " Miniature 

 Spectroscope," with the diaphragm off, but it gives less light 

 than simple prisms. I have also tried a " half-prism spectro- 

 scope," by Hilger, but unsuccessfully; but I find that by taking 

 off the outer lens of the eyepiece and the diaphragm much more 

 light is obtained ; I have not, however, had an opportunity of 

 trying this plan yet on an aurora. 



The number of nights of aurora on which I have seen each 

 line, between 1871, November I, and 1883, March 27, is as 

 follows : — 



$ 



5 



26 



a € (, n y 

 >t 83 34 14 7 33 



On thirteen nights I could not be sure of any line, but on six 

 of these I suspected o, or else there was an abrupt fading away 

 about where a should come. There were other auroras— mostly 

 faint ones — whose spectra I did not observe. 



The lines visible in the spectrum often vary in the course of a 

 few minutes, and indeed are not always the same in different 

 parts of the sky at the same time. I have never been able to 

 detect that any particular feature of the spectrum belongs to 

 any particular type or feature of aurora, except that the line /3 

 belongs to red auroras. 



Dr. Vogel thinks it probable thit the auroral spectrum is a 

 modified air-spectrum. The following are the most striking 

 coincidences or approximations between my revised li-t of 

 auroral lines and Vogel's lists of lines in the spectra of air and 

 its con-tituents. They are sufficient to make the subject one 

 worthy of consideration ; but perhaps this is as much as can as 

 yet be said. There are other approximations to very faint air 

 or gas lines, which he regards as of some importance ; but, as 

 the lines in the latter spectra are so numerous, one would 

 naturally expect such coincidences accidentally. 



Aurora. 



e 1 5237 



e 5226 

 « 2 5 ! 99 



C 5°oi 



1 4870 

 7 4688 



« 43 66 



5 4278 



Aurora Spectrum Coincidences. 

 Air. 



Tar} 



5231 dull. 



N 5224 very bright. 



O 5 '&9 vel T bright. 



H 5187 very bright. 



N 5004 bright. 



Ail . /S008 very bright. 

 \ 5002 very bright. 



O 4870 moderately bright. 



N 4704 very intense. 



O 4372 moderately bright. 



N 4363 bright. 



N 4357 bright. 



H 4358 very bright. 



N 4275 very bright. 



A. S. Herschel has pointed out the proximity of $ to the dark 

 atmospheric band a at 6279. 



Sunderland Thos. William Backhouse 



SCIENCE A T KAZAN"- 



""THE Kazan Society of Naturalists, which began its Memoirs 

 in 187 1 with the remarkable work of M. M. Bogdanoff 

 on the birds and mammals of the black earth region of the 

 basin of the Volga, has continued since to publish a series 

 of most valuable explorations of the region of the lower 

 Ural, Volga, and Siberia. We notice thus in the first eight 

 volumes of its Memoirs the researches on earthquakes in 

 Siberia, in Turkestan, and on the Ural, by M. Orloff ; several 

 valuable papers on the Geology of the Obschiy Syrt plateau, by 

 M. Sintsoff ; of the Government of Vyatka, by M. Krotoff; of 

 the Government of Kazan, by Prof. Stuckenberg ; and of the 

 banks of the Kania, by M.Zaitseff; a work on the birds of 

 Caucasus, by M. Bogdanoff; a paper on the Teleostei of the 

 mouth of the Volga, by M. Yakovleff ; the history of the deve- 

 lopment of the Acipenser slurio, by M. Zalensky ; and myco- 

 logical researches, by M. Sorokin ; several papers on the flora 

 of the Government of Perm, by M. Kryloff; and two papers by 

 M. Levakovsky on the substitution of certain s; ecies of plants 

 for others in a given region ; as well as several valuable re- 

 searches into the anthropology of the Bashkirs, Voguls, and 

 Votyaks, by MM. Malieff, Sorokin, and Ostrovsky. 



The three last volumes of the Memoirs, which w e have now 

 before us, contain also many valuable papers. In the depart- 

 ment of botany we notice the second part of M. Krylofl's flora 

 of the Government of Perm. It contains a complete list of all 

 Pbanerogamre discovered in this interesting province, which 

 includes the Ural Mountains, completed by special researches 

 into the subarctic and Alpine flora of this region. A map 

 sho « s pretty well how such plants as the Viburnus opulus, the 

 Cystisus biflorus, the Tilia parviflora, and the cereals are stopped 

 in their extension by the Ural Mountains, reappearing again on 

 their eastern slope ; whilst others, HI e the Querent pedunculate!, 

 or the Acer platanoides, are stopped in their extension towards 

 the east by the western spurs of the Ural and the lowlands of 

 Siberia, their north-eastern limit meeting nearly together with 

 the south-western limit of extension of the Finns cembra, the 

 I.onicera ccerulea, the Spinva media, and Polygonum viviparum. 

 The whole list contains 948 An^iospermae, and 8 Gymnosperma". 

 The Cryptogamse are represented by 38 Lycopodiacea: and 124 

 Lichens. — Or. Martianoff publishes valuable materials for the 

 flora of the Minusinsk region in Eastern Siberia, comprising a 

 sketch of its climate (according to five years' meteorological 

 observations by A. Krapotkin) and its physico-geographical 

 characters. The flora of Minusinsk is much varied, as it e n- 

 bodies three separate botanical regions : the Alpine, the forest, 

 and the steppe floras, intermingled with one another. Its 

 general character is that of the Altai region, and out of 777 

 Phanerogams, no less than 714 are Altaic, whilst only 59 belong 

 to the flora of Eastern Asia. The Alpine flora has but 104 re- 

 presentatives ; the forest-flora is the most widely spread, and 

 at the same time the richest ; it is represented by 579 species. 

 The steppe fl ra, which covers nearly one-quarter of the 

 Minusinsk district, and appears sporadically even on the plateaux 

 of the hilly tracts, numbers 315 species. We can only notice 

 here the excellent botanical sketches of separate parts of this 

 "Siberian Italy" which we find in M. Martianoff's work. His 

 list of plant*, which contains 760 species of vascular plants, is 

 unusually rich also in lower plants, the number of determined 

 Fungi and Myxomycetes comprising 644 species. — An interesting 

 work which has cost much labour to its author, M. Kryloff, is a 

 description of all drugs — mostly plants — used in the popular 

 pharmacies of the Governments of Kazan and Perm. The 1st 

 comprises about 200 plants, with a description of their use in 

 popular medicine. 



The zoological papers in this volume are but two : — On the 

 innervation of the heart of the Eso.x lucius and Acipenser ruthe- 

 nus, by MM. Kazem-beck and Doguel ; and on the ear-labyrinth 

 of the Plagiostomi {Acipenser ruthenus, A. sturio, and A.schiffa), 

 by M. Sizoff. Both papers have appeared also in the Archiv 

 fur mieroskopisehe Anatomic. 



Geology is represented hy the following papers : — On the 

 upper part of the mottled marls, by Prof. Stuckenl-erg ; 

 on the Permian in the Governments of Kazan and Samara, 

 by A. Zaitseff; and on the geology of the Volga between 

 Nijni-Novgorod and Kazan, by P. Krotoff. The Zechstcin 

 appears in the region situated between the Kama, the water- 



1 Memoirs of the Society of Naturalists at tlie Kazan University, vols. 

 ix. f x.| and xL, 1880-1882. 



