July 24, 1913] 



NATURE 



54' 



"The Museums Association, at its annual confer- 

 ence in Hull, 1913, declares itself in cordial sympathy 

 with the proposal to make provision in the grounds 

 of the Crystal Palace for a British Folk-Museum on 

 the open-air plan, and expresses the hope that the 

 Right Hon. the Lord Mayor of London will use 

 every endeavour to carry the proposal into effect." 



The conference concluded its business by electing 

 Mr. Charles Madeley, director of the Warrington 

 Museum, to be president for the 1914 meeting, which 

 is to be held at Swansea. 



THE ELECTRIC FURNACE SPECTRUM OF 

 IRON. 



IN Nature for April 24 (p. 200) we gave a brief 

 account of the researches carried on by Mr. A. S. 

 King, of the Mount Wilson Solar Observatory, upon the 

 variations of the spectrum of titanium in the electric 

 furnace. Mr. King has now concluded an investiga- 

 tion of the variation with temperature of the electric 

 furnace spectrum of iron, an account of which is 

 published in No. 66 of the Contributions from the 

 Mount Wilson Solar Observatory. 



This communication, like others of his on a similar 

 subject, is of great interest, because it shows that 

 the spectrum of a substance is not the same for any 

 temperature. By knowing what spectrum is given 

 at a known temperature it is possible to determine 

 the temperature of stars or portions of the sun, and 

 so utilise these laboratory researches for stellar and 

 solar spectroscopy. 



While a great amount of work has already been 

 done in the case of iron, one of the earliest being 

 the differentiation of temperatures by the short- and 

 long-line method of Lockyer, Mr. King has all the 

 advantages of the latest form of furnace and method 

 of determining accurately the varying temperatures 

 for the lower stages of temperature. 



One of the great problems in these investigations is 

 to determine whether the changes described are due 

 to temperature or to electrical or chemical conditions 

 which are present in different degrees in the sources 

 of heat. 



In a brief summary like this it is not possible to 

 state all the conclusions which the research has 

 led Mr. King to deduce, but the more important may 

 be briefly summarised. In the first place, he has 

 been able to divide into six classes the relative in. 

 tensities of the iron lines in the visible spectrum for 

 three furnace temperatures and the arc, basing them 

 on the temperature at which a line appears in the 

 furnace, and its rate of growth as the temperature 

 increases. In passing from the furnace to the arc the 

 changes in relative intensity may generally be 

 accounted for by a difference in conditions equivalent 

 to a large temperature difference. The ultra-violet 

 was found a rich region for lines, and it was noted 

 that increase of temperature corresponded to an ex- 

 tension of the line spectrum towards shorter wave- 

 length. The increase in intensitv of lines from the 

 outer vapours into the core of an iron arc was found 

 usually to resemble the rate of growth shown by the 

 same lines with rising furnace temperature, and this 

 the author suggests renders it unlikely that chemical 

 reactions in the outer vapours affect the relative 

 intensity of arc lines in any large degree. 



So far as the visible region is concerned the en- 

 hanced iron lines are above the furnace stage, no 

 lines being observed in the furnace spectrum. The 

 furnace spectra at low and medium temperatures were 

 found, except perhaps in the ultra-violet, to be very 

 similar to those of the several flames. 



The author concludes that while there is no definite 



no. 2282, VOL. qi] 



proof that temperature radiation in a stricl sense takes 

 place, the position of temperature as the exciting and 

 regulating agent in furnace phenomena seems lo be 

 clear. 



ANTARCTIC LICHENS} 

 I" ICHENS form a quite exceptional group of plants 

 -1— ' with many peculiar features, the chief among 

 which is the fact that they are compound organisms, 

 a lichen consisting of a fungus individual and 

 numerous alga individuals — the fungus with its 

 branched and interlacing threads has grown around 

 the alga cells and enclosed them in a nest. The 

 result is that the lichen can grow in places which 

 would be quite unsuitable for the independent exist- 

 ence of either the fungus or the alga of which it is 

 composed. Algae grow in water or in moist places, 

 while most fungi are extremely sensitive to cold and 

 drought, but lichens can thrive in the bleakest posi- 

 tions and in the most severe climates, as on bare 

 mountain rocks and in the farthest circumpolar re- 

 gions reached by explorers — provided that the land 

 surface is not covered by perpetual snow. In alpine 

 and arctic regions, lichens do important pioneer work, 

 helping to break up the hardest rock surfaces and 

 prepare soil on which other plants can grow ; while 

 on steeply inclined and bare rock, lichens, along with 

 minute algjgj are in general the first colonists. 



These pioneer lichens are of the flat crustaceous 

 and foliose types, the former attached closely to the 

 substratum by their entire underside, the latter cling- 

 ing more loosely, and being therefore detachable 

 without chipping off bits of the rock itself in order 

 to obtain specimens. On less steeply inclined parts, 

 where the vegetation is older, the shrubby or fruti- 

 culose lichens are added ; these are fixed at the base 

 only, and show much greater variety of form than is 

 found among the encrusting and leafy types. 



In his report on the lichens of the Swedish Ant- 

 arctic expedition, 1901-3, under Dr. O. Nordenskjold, 

 which has recently been published, Dr. O. V. Darbi- 

 shire adds to his descriptions of the new species an 

 interesting summary and discussion of the distribu- 

 tion of lichens in the arctic and antarctic regions 

 generally. Unfortunately the good ship Antarctic was 

 crushed by ice in January, 1903, and a large portion 

 of the plants collected during her cruise along the 

 coast of Graham Land had to be abandoned when she 

 sank a month later ; but though doubtless a consider- 

 able amount of material was lost in this disaster, a 

 rich harvest was brought back by the botanical mem- 

 bers of the Swedish expedition. This includes no 

 fewer than 145 species of lichens, of which thirty- 

 j three are new. 



An analysis of the results of antarctic expeditions 

 up to and including Charcot's (1905) shows that at 

 present 106 lichen species are known from the land 

 which lies strictly within the antarctic limits, and that 

 of these thirty-two also occur in subantarctic America, 

 twenty-five in New Zealand, and sixteen in South 

 Georgia, showing a very close affinity between the 

 antarctic lichen flora, on one hand, and the American 

 and New Zealand floras, on the other — the difference 

 to the disadvantage of the latter being accounted for 

 bv the greater nearness of the subantarctic American 

 region to the extreme limit of the southern drifting 

 pack-ice. The lichens of subantarctic America and 

 New Zealand are also very nearly allied, for out of 

 133 lichens in the former flora, 113 are found in New 



1 "The Lichens of the Swedish Antarctic Expedition." By On-, 

 Vernon Darhishire. Wissensch. Ergebn. der schtvedischen Kadpo'ar- 

 Expedition. 190T-1903. Band iv., Lief. ri. Pp. 1—734-3 plates. (London 

 Dulauand Co., Ltd., 1912.) Price Is. (Subscription price 6s.) 



