NA TURE 



[May 14, 1896 



Memoirs (Zafitsti) of the Caucasian Branch of the Kiissian 

 Geographical Society, vol. xviii., Tiflis, 1896. — Review of the 

 atmospheric sediments fallen in Caucasia during the spring and 

 summer of 1S94, by A. Wornesensky, with four maps. — A 

 journey to the mountain region of the district Tchernoniorsk, 

 by N. Albof, with a map of the district, 67 miles to the inch. 

 The author has visited, for botanical purposes, some of the least- 

 known valleys of tlie region, and now gives the diary of his 

 journey. — Studies in the geographical botany of Western Trans- 

 caucasia, by the same author. The article is full of valuable 

 data. Several interesting finds are mentioned, such as' the 

 new species Ainphoricapus elegans, and a Campannla, which 

 so much exceeds all known species of the same genus by its 

 beauty, that M. Albof proposes for it the name of Campanula 

 regina, and remarks that its general shape so much difl'ers from 

 all other now living Campanula species that it must be, without 

 doubt, a remainder from a foregone geological flora. — On the 

 Kumyks, an anthropological sketch, by J. Pantukhof. — The 

 Pshaves and their land, by M. Khizanachwili. — A journey to the 

 •central part of the land of the Chechenes, by Mdme. A. 

 Rossikof, with a map, three miles to the inch, of this very little 

 part of the main ridge. — A statistical description of the govern- 

 ments of Baku and Kars, from the "Caucasian Calendar." — 

 The state of the glaciers on the northern slope of the Caucasus, 

 by K. Rossikof, being the results of the measurements of the 

 motion of several glaciers in 1893 and 1894 ; and on the present 

 state of the desiccating lakes of the northern slopes of the 

 Caucasus, by the same author. The same volume contains, 

 as a supplement, a most welcome atlas of ethnographical 

 maps of Transcaucasia, drawn by the Secretary of the Society, 

 E. ICondratenko. The maps are the result of many years' 

 ■work. The classification of the more than sixty different stems 

 which inhabit Transcaucasia is the result of the remarkable 

 works of Baron Uslar and his follower, M. Zagursky ; and the 

 inumerical data as to the numbers of inhabitants belonging to 

 each stem are obtained from a census made in the years 

 1886-1891. The maps, on the scale of thirteen miles to the 

 inch, are seven in number, and represent the governments of 

 Tiflis, Kulais, Baku, Elizabethpol, Daghestan, Erivan, and 

 Kars. The limits of each village community are indicated, and 

 the nationality which prevails in each village is shown in 

 difi'erent colours ; while, on the borders of each map, special 

 coloured diagrams give the ethnographical composition and the 

 numbers of each nationality for each town and district, as well as 

 for the whole government, so that one sees at a glance their 

 numerical proportions. Full tables of figures are given by M. 

 E. Kondratenko in the text of the Zapiski. The value of this 

 work is enhanced by an ethnographical map of Turkish Armenia 

 and Kurdistan, published in the same volume. It is based upon 

 V. Cuinet's statistics, given in his work, "LaTurquie d'Asie," 

 and shows in different colours the percentage of Turks and 

 Armenians in each kata, or sub district. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, April 30. — " The Total Eclipse of the Sun, 

 April 16, 1893. Report and DisciLssion of the Observations 

 relating to Solar Physics." By J. Norman Lockyer, C.B., 

 F.R.S. 



The memoir first gives reports by Mr. Fowler and Mr. 

 Shackleton as to the circumstances under which photographs of 

 the spectra of the eclipsed sun were taken with prismatic 

 cameras in West Africa and Brazil respectively on April 16, 

 1893. These are followed by a detailed description of the 

 phenomena recorded, and a discussion of the method employed 

 in dealing with the photographs. The coronal spectrum and 

 the question of its jiossible variation, and the wave-lengths of 

 the lines recorded in the spectra of the chromosphere and 

 prominences, are next studied. 



Finally, the loci of absorption in the sun's atmosphere are 

 considered. 



The inquiry into the chemical origins of the chromospheric and 

 prominence lines is reserved for a subsequent memoir. 



The general conclusions which have been arrived at are as 

 follows : — 



(I) With the prismatic camera, photographs may be obtained 

 with short exposures, so that the phenomena can be recorded at 

 short intervals during the eclipse. 



NO. 1385, VOL. 54] 



(2) The most intense images of the prominences are produced 

 by the H and K radiations ot calcium. Those depicted by the 

 rays of hydrogen and helium are less intense, and do not reach 

 to so great a height. 



(3) The forms of the prominences photographed in mono- 

 chromatic light (H and K), during the eclipse of r893, ''° "°' 

 differ sensibly from those photographed at the same time with 

 the coronagra]ih. 



(4) The unckmbted spectrum of the corona in 1893 consisted 

 of eight rings, including that due to 1474 K. The evidence that 

 these belong to the corona is absolutely conclusive. It is 

 probable that they are only represented by feeble lines in the 

 Fraunhofer spectrum, if present at all. 



(5) All the coronal rings recorded were most intense in the 

 brightest coronal regions, near the sun's equator, as depicted by 

 the coronagraph. 



(6) The strongest coronal Hne, 1474 K, is not represented in 

 the spectrum of the chromosphere and prominences, while II 

 and K do not appear in the spectrum of the corona, although 

 they are the most intense radiations in the prominences. 



(7) A comparison of the results with those obtained in previous 

 eclipses confirms the idea that 1474 K is brighter at the maximum 

 than at the minimum sun-spot period. 



(8) Hydiogen rings were not photographed in the coronal 

 spectrum of 1893. 



(9) D3 was absent from the coronal spectrum of 1893, and 

 reasons are given which suggest that its recorded appearance in 

 1882 was simply a photographic eft'ect due to the uneipial 

 sensitiveness of the isochroniatic plate employed. 



(10) There is distinct evidence of periodic changes of the con- 

 tinuous spectrum of the corona. 



(11) Many lines hitherto unrecorded in the chromosphere and 

 prominences were photographed by the prismatic cameras. 



(12) The preliminary investigation of the chemical origins of 

 the chromosphere and prominence lines enables us to state 

 generally that the chief lines are due to calcium, hydrogen, 

 helium, strontium, iron, magnesium, manganese, barium, 

 chromium, and aluminium. None of the lines appear to be due 

 to nickel, cobalt, cadmium, tin, zinc, silicon, or carbon. 



(13) The spectra of the chromosphere and prominences 

 become more complex as the photosphere is approached. 



(14) In |iassing from the chromosphere to the prominences, 

 some lines become relatively brighter but others dimmer. The 

 same line sometimes behaves differently in this respect in different 

 prominences. 



(15) The prominences must be fed from the outer parts of the 

 solar atmosphere, since their spectra show lines which are 

 absent from the spectrum of the chromosphere. 



(16) The absence of the Fraunhofer lines from the integrated 

 spectra of the solar surroundings and uneclipsed photosphere 

 shortly after totality need not necessarily imply the existence of 

 a reversing layer. 



(17) The spectrum of the base of the sun's atmosphere, as 

 recorded l)y the prismatic camera, contains only a small number 

 of lines as compared with the Fraunhofer spectrum. Some of 

 the strongest bright lines in the spectrum of the chromosphere 

 are not represented by dark lines in the Fraunhofer spectrum, 

 and some of the most intense Fraunhofer lines were not seen 

 bright in the spectrum of the chromosphere. The so-called 

 "reversing layer" is therefore incompetent to produce the 

 Fraunhofer spectrum by its absorption. 



(18) Some of the Fraunhofer lines are produced by absorption 

 taking place in the chromosphere, while others are produced by 

 absorption at higher levels. 



(19) The eclipse work strengthens the view that chemical 

 substances are dissociated at solar tem])eratures. 



May 7. — "On the Occurrence of the Element Gallium in 

 the Clay- Ironstone of the Cleveland District of Yorkshire." Hy 

 Prof. W. N. Hartley, F.R.S. , and Hugh Ramage. 



The evidence of the existence of gallium in the ore and in the 

 metal rests on the measurements of the wave-lengths of the 

 lines in a large number of ]ihotographed spectra and upon the 

 relative strengths of the lines in the different materials examined 

 and in the precipitates obtained therefrom. 



Exanijiks are given showing the nature of this evidence. 



Chemical Society, April 23. — Mr. A. G. V. Harcourt, 

 President, in the chair. — The following papers were read: — The 

 constitution of the cereal celluloses, by C. F. Cross, E. J. Bevan, 

 and C. Smith. The cereal celluloses may be resolved by acids 

 into a re>idue of normal cellulose and a soluble furfuroid con- 



