Nov. 13, 1879] 



NATURE 



37 



temperature, the resulting spectrum under the supposition 

 that each element is really an element, would never be 

 simpler than the combined spectra of the various 

 ■elements. 



On the other hand, if the elements were really com- 

 pounds of some one primordial atom, we might expect 

 that a very high temperature would split up their atomic 

 structure, and simplify their spectra, so that at an 

 enormously high temperature a mixture of all the 

 elements might nevertheless give us a very simple 

 spectrum. We might likewise expect that different 

 elements might split up into common constituents, so that 

 at a very high temperature the spectra of these elements 

 would have certain lines in common. 



It is in the larger masses of the Universe, the sun and 

 stars that we must look to find a mixture of all kinds of 

 matter at very high temperatures, and when we have a 

 brilliant bluish-white star containing a large proportion of 

 the more refrangible rays we have every reason for sup- 

 posing this star to be at a very high temperature. Now 

 such stars exhibit an extreme paucity in the black lines 

 which appear in their spectra, in which there is hardly 

 anything else than certain prominent lines seen in the 

 spectra of hydrogen, calcium, magnesium, and sodium. 

 Lockyer, who has devoted great attention to this subject, 

 argues therefore as follows. If it be true that as a rule 

 the atmospheres of the whiter and presumably hotter stars 

 contain fewer elements and those of the smallest atomic 

 weight and that as stars diminish in whiteness their 

 atmospheres rise in complexity of structure this undoubt- 

 edly tells in favour of the power of high temperature to 

 split up the so-called elements. He has quite recently 

 carried this reasoning into another field. The Fraunhofer 

 lines give us the integration of the absorptions of all the 

 strata of the solar atmosphere. Now spot phenomena 

 occur in a restricted stratum of this atmosphere, and this 

 stratum is low and therefore hotter than the overlying 

 portions. We can tell the spectral lines special to a spot 

 by their widening, and the number of lines widened is 

 small in comparison with the Fraunhofer lines. Here 

 again we have simplicity brought about by high tempera- 

 ture in the low levels in the sun as in the stars hotter 

 than the sun. 



Let us now ask whether the spectra of the various 

 elements have or have not certain lines in common. It 

 used to be imagined that they had not. 



When, however, they have been examined under 

 great dispersive power there has been found reason to 

 ■qualify this assertion. There are certain lines in the 

 spectra of each element which appear long and thick, 

 their predominant notes as it were, and it has been 

 found that while such a line for instance is exceedingly 

 prominent in some one element other elements appear to 

 possess it, only not nearly so prominently. Lockyer's 

 argument from this was that, on the a-sumption that the 

 elements are truly elementary, the line in the other 

 elements was caused by traces of impurity. He has, 

 however, recently had reason to believe that there are 

 coincidences between the spectra of the various elements 

 not of this nature. There are coincidences of lines which 

 are not the prominent lines of any one spectrum and they 

 give no signs of that variability of brightness that nvght 

 be expected to characterise lines due to impurities. These 

 lines he has called basic lines. As may be readih imagined 

 in a branch of knowledge which is so new we shall have 

 long to wait for facts. Hence we cannot test this con- 

 clusion by referring to the spectra of stars. But Lockyer 

 has already shown that wc can test it by means of the 

 spectra of sun-spots, and here the facts are certainly in 

 support of it. The basic lines are more prominent in the 

 spectra of spots than in the spectrum of the sun generally, 

 and further they are more prominent at epochs of sun- 

 spot maximum than during times of minimum. 



But we must have a clear conception of what we mean 



when we suppose that the so-called elements are split up 

 at a very high temperature. 



If we apply a very powerful source of electricity we 

 obtain certain peculiar lines from the vapour of calcium. 



Now if we could (like the Demon of Maxwell) catch 

 hold of and segregate — put into a box as it were ail these 

 minute entities that give us this suspicious line at a high 

 temperature, and further if we could keep their high 

 temperature up I think it is probable that we might obtain 

 something which is not calcium, or at any rate, something 

 simpler than the molecule of calcium as this appears at 

 lower temperatures. But we are not yet able, and 

 perhaps we may never be able, at an ordinary temperature 

 to present the chemist with some other substance derived 

 from calcium which is not calcium. 



To conclude there seems little doubt that spectrum 

 analysis will, as it advances, throw great light on the 

 ultimate constitution of matter and it therefore justifies 

 the remarks which I made at the commencement of this 

 lecture. 



THE SWEDISH NORTH-EAST PASSAGE 

 EXPEDITION 



DESPATCHES have been received by Mr. Oscar 

 Dickson, of Gothenburg, from Prof. Nordenskjold, 

 giving an account of the wintering of the Vega, down to 

 April 1 ; letters from Lieut. Palander and other members 

 of the North-East Passage Expedition have also been 

 published, some of them bringing down the narrative to 

 a later date. From these we gather the following 

 particulars : — 



The Veya was frozen in on September 28, in 67 7' N. 

 lat. and 1 73^° long. W. from Greenwich, at the northern- 

 most extremity of Behring's Straits. The land in the 

 neighbourhood forms an extensive slightly rolling plain, 

 bounded on the south by gently-rising hills, which, farther 

 into the interior, are said by the natives to reach a con- 

 siderable height. The plain is occupied to a large extent 

 by lagoons separated from the sea by low sandy beaches. 

 When the Vega was frozen in, the ground was covered 

 with hoar frost and frozen, but still free of snow, so that 

 it was possible to form some idea of the flora of the 

 region. Close to the beach, compact beds of Elyinus were 

 intermixed with carpets of Haliantlius peploidcs ; next 

 there stretched a poor level gravelly plain, only covered 

 with a black lichen, Gyrophora prohoseidea, and some few 

 flowering plants, amongst which Armeria sifiirica was the 

 most common. South of this, again, was a tract occupied 

 by lagoons and small lakes, whose shores were covered 

 with luxuriant vegetation, consisting of grasses and 

 Carices. On the neighbouring high ground, where the 

 soil, derived from weathered strata of gneiss and dolerite, 

 is richer, the vegetation is marked by greater variety. 

 Here were thickets of willows, extensive carpets of 

 Empitrum iii« nun, and Andromeda tetragotta, and large 

 tufts of a species of Artemisia. Here were found also 

 the frozen remains of the rt-d whortleberry, the cloud- 

 berry, taraxacum officinale, and other plants peculiar to 

 the high north. In an excursion to the interior on 

 October 8, Lieut. Nordquist observed that on the driest 

 parts of the tundra the most common plants were Aim 

 alpina and Poa alpina; on the lo>ier places, Glycerin, 

 pedicularis, and Ledum pa/ustie. Petasites frigida and 

 a species of Salix occurred everywhere, the latter growing 

 in large compact masses covering spots several hundred 

 square feet in extent, the bu-hes in some places being 3 

 to 4 feet high. 



In the neighbourhood of the Vela's winter quarters 

 there were six small encampments, numbering from three 

 to twenty-five tents each, inh.ibited by Tchuktches to the 

 number of about 200. With these natives there was much 

 friendly intercourse. They were allowed free access to 

 the deck from which, though covered with a multifarious 



