398 



NATURE 



[Feb. 



composition of vegetable matter. It is to be found in the ashes 

 of all timber and plants in association with lime and soda ; but, 

 in this case we find the potash, or more correctly speaking, the 

 oxide of the metal potassium, is in chemical combination with 

 oxalic acid ; thus forming a compound salt, highly crystallized. 

 The paradoxical feature of the phenomenon is presented by the 

 query — Where did the oxalic acid come from to combine with 

 the oxide of potassium? Analysis has failed to detect oxalic 

 acid in the wood or leaves of the Fagus. There are certain well- 

 known plants which furnish oxalic acid. Notably, the Oxalis 

 acftocella, from which it used to be extracted before the great 

 advances of chemistry enabled man to be independent of that 

 plant as its source. Combined with lime it has been found in 

 some lichens, while the roots of rhubarb and bistort contain it in 

 small quantity in combination with potash ; but this is the first 

 instance, it seems, of this organic combination being found in 

 a solid, compact, crystallized form, especially in the heart of a 

 tree." 



The fiery sunsets which revealed the existence of the Krakatab 

 dust in the atmosphere were also noticed by Prjevalsky in 

 November and December 1883, as he was crossing the Gobi 

 and the Northern Ala-shan. He describes them as follows in 

 his "Fourth Journey to Central Asia" : — "After a bright day, 

 which is here the usual state of the weather during the winter, 

 light cirrus and cirro-stratus clouds appeared in the west, just 

 before sunset, or immediately after. Probably they were floating 

 all day long in the upper strata of the atmosphere, but became 

 visible when the sun went beneath the horizon. Immediately 

 after that, the whole of the western part of the sky became lighted 

 by a bright cream light, which soon acquired a violet colour in 

 the upper parts, with stripes of shadows. At the same time the 

 shadows of the night rose in the east, dark lilac in the lower 

 parts, and violet in the upper parts. The violet colour vanished 

 by and by in the west, and a segment of bright orange colour 

 appeared close by the horizon, on a cream background. Some- 

 times it acquired a light red colour, but sometimes it became 

 bright red or even blood-red. In the meantime the lilac colour 

 disappeared in the east, and all the sky became of a gray-lilac 

 colour. Amidst the changing colours in the west, Venus glowed 

 like a diamond descending beneath the horizon at the time 

 when the twilight, which lasted for about one hour and a half, 

 ■came to an end. During nearly all that time the glow in the 

 west was casting shadows, and all objects in the desert appeared 

 in a fantastic light. The sunrise was accompanied by the same 

 phenomena, but in a reverse order: sometimes the morning 

 twilight began with the appearance of a blood-red colour. At 

 full moon the phenomena were less striking, and in the atmo- 

 sphere of Northern Ala-shan, which is charged with dust, we 

 saw them less often than in the Central and Northern Gobi." 



A HUGE Greenland whale, 90 feet in length, after having 

 been seen in various parts of the Cattegat, lately went ashore in 

 the Sound, and was killed. During the previous twenty years 

 a whale had not been seen in these waters. The skeleton is to 

 be forwarded to the Copenhagen Museum. 



Prof. O. Torell and Dr. Trybom have petitioned the 

 Swedish Government for funds sufficient to enable them to 

 -continue their researches on the sea fisheries of Sweden, and to 

 establish a biological station on the west coast. 



Last summer Dr. Th. Thoroddsen effected some further 

 explorations in the interior of Iceland, visiting parts hitherto 

 untraversed. It is said that in Norse times, in the district 

 west of Hecla, by the River Thjorsaa, a numerous popu- 

 lation inhabited a fertile valley, which was laid waste in 1343 

 by a terrible volcanic eruption of the Raudukambar Moun- 

 tain. Dr. Thoroddsen now reports that this mountain is 

 aot a volcano at all, and that in historical times no volcanic 



eruption has devastated this valley; but he is of opinion that the 

 colony in question was destroyed through an eruption of Hecla 

 in the middle of the fourteenth century. Dr. Thoroddsen after- 

 wards explored the desert land south of the Hofjjokul, parti- 

 cularly a mountain range, called Kjerlingarfjoll, close to the south 

 of it. These mountains had never been exploied before, and 

 Dr. Thoroddsen found a country which he describes as very 

 remarkable. It was known in the low lands that there 

 were some valleys with hot springs, steam having been seen 

 from a distance, but the springs had never been visited. Dr. 

 Thoroddsen found grand sulphur springs in great numbers, 

 which, he states, far excel the well-known ones at Myvain 

 and Krisuvik. There are also numbers of large boiling mud 

 pools — blue, red, yellow, and green in colour — whilst steam 

 penetrates everywhere through fissures in the earth with terrific 

 noise. One steam jet, 6 to 9 feet in height, kept up such a 

 continual roar that it was impossible to hear the loudest shouts 

 for a longdistance. Several subterranean cavities were also found 

 containing boiling clay pools, and around one of them the earth 

 trembled far and wide, whilst far down below in the earth a 

 noise was heard like that which might proceed from a gigantic 

 butter-churn. The valleys in which these springs and mud pools 

 are found are surrounded by extensive and deep snow-fields 

 with innumerable fissures, through which the roar of the steam 

 far below the snow can be heard in some places, whilst in others 

 the steam escapes through them. The ground in these valleys is 

 so hot that only with the greatest care is it possible to tread on 

 the thin crust of clay covering the boiling mud below. 



The additions to the Zoological Society's Gardens during the 

 past week include a Ring-tailed Coati {JVasiia rufa 9 ) from 

 Brazil, presented by Mr. N. T. Williams ; three Herring Gulls 

 [Larus argentatus), British, presented by Mr. L. V. Harcourt ; 

 six Moorish Geckos {Tarentola mauritanica) from the south of 

 France, presented by Masters F. and O. Warburg ; a Thigh- 

 striped W^allaby {Halinattirus thetidis 9) from New South 

 Wales, deposited ; a White-throated Capuchin {Cebus hypoleu- 



cus), a Capuchin (Cebus sp. inc.) from Central America, 



purchased; an lLla.nd (Oreas canna ? ), a Yellow-footed Rock 

 Kangaroo {Petrogale xanlhopiis 6), born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



The Multiple Star C Cancri. — This remarkable stellar 

 system has justly attracted much attention ever since Sir W. 

 Herschel discovered in 1781 that it was really composed of 

 three, not two stars, the principal star being itself a close 

 double. But the intere-t with which the system was regarded 

 was greatly increased by the remarkable paper which Prof. 

 O. Struve produced upon the subject, and communicated to the 

 Paris Academy of Sciences in 1874 {Co7nptcs rendus, vol. Ixxix. 

 p. 1463), and in which he pointed out a noteworthy inequality 

 m the [motion of the distant companion C, having a period 

 of about twenty years. The question was again taken up by 

 Prof. Hugo Seeliger in 1881, in a paper entitled " Ueber die 

 Bewegungverhaltnisse in dem dreifachen Sternsystem i Cancri," 

 and presented to the Vienna Academy of Sciences on May 5 of 

 that year. Prof. Seeliger has continued his discussion of the 

 observations of the star, and has recently published a further 

 paper on the subject, which appears in the Memoirs of the 

 Royal Bavarian Academy of Sciences, Munich, under the title 

 " Fortgesetzte Untersuchungun ueber das mehrfache Stern- 

 system f Cancri." The result of his further labours has been 

 in effect to confirm the results he had obtained in his earlier 

 work, and those which Prof. Struve had brought out in 1874. 



The three stars A, B, and C, have the magnitudes respec- 

 tively 5 c, 57, and 5 "3. The proper motion of the system 

 amounts in a century to -f 10" '6 in R. A., and to - 11" in 

 Decl. The close pair, A and B, first separated by Herschel, 

 have a motion round one another in about sixty years, their 

 apparent distance from each other varying from about o"'6 to 

 i""i ; whilst C, the more distant companion, has moved through 

 about 55° of position-angle round the other two since Herschel's 



