Jan. 29, 1880] 



NATURE 



2P1 



favourably ; more frosty weather having prevailed the water 

 freezes behind the boats of the men trying to open a channel in 

 the ice-barrier. Immense disasters are anticipated from the 

 thaw if some means are not found to work more effectually. 

 It is stated that the block was formed principally in con- 

 sequence of the situation of the bridge of Saumur, which some 

 competent engineers proposed to demolish many years ago as 

 creating a danger on the occasion of inundations. The proposal 

 was renewed during the present crisis without having met with 

 nny success. 



The Canal Saint Martin, which is used so largely for provi- 

 sions of Paris, has also been entirely frozen, and the blocks of 

 ice not having melted, as in the Seine, the Director of the City 

 Works is busy in disencumbering it as much as possible. The 

 difficulty is not so much in cutting the ice as in sending it into 

 the Seine by the flood gates. Although having a length of only 

 a few kilometre?, the Canal St. Martin has so many locks, that 

 the problem of freeing it is one of the most difficult than can be 

 imagined. 



This week the Commission of the Municipal Council of Paris 

 will deliberate upon the desirability of continuing the experi- 

 ments on electric lighting in the Avenue de l'Opera. Since the 

 article by M. de Fonvielle was written, the Siemens brothers 

 have exhibited their lamps on one of the largest confectionery 

 shops on the Boulevard Montmartre. It works very well, and 

 creates some sensation in Paris. 



At the last meeting of the St. Petersburg Gardening Society, 

 Prof. Beketoff made an interesting communication on the dis- 

 covery in the government of Ekaterinodav, in a wild state, of 

 vine-plants and of the Hungarian oak (Quercus cervis). Both 

 are probably degraded plants, affjniing remarkable specimens of 

 natural transformism. 



Among the numerous bibliographical indexes which have 

 lately appeared in Russia, we notice the "Bibliography of 

 works in Finance, Industry, and Trade in Russia, from 1 714 to 

 1870," by M. Karataeff, which contains a complete systematic 

 list of more than 6,000 books, papers, and newspaper notices on 

 these subjects. The work has just appeared at St. Petersburg. 



We notice in the last number of the Journal of the Russian 

 Chemical aud Physical Society, the sixth part of the memoir by 

 Prof. Menshutkin, on the influence of isomerism of acids on the 

 formation of compound ethers. As seen from numerous mea- 

 surements published by the author, the isomerism of acids is of 

 great influence on the absolute and relative rate of etherisation, 

 the primary acids being etherised in from 72 to 120 hours, whilst 

 no less than 336 hours are necessary for the complete etherisation 

 of several tertiary acids. Besides the rate of etherisation 

 decreases also with the increase of the molecular weight. 

 The same journal contains a paper by MM. Eeilstein, and 

 Courbatoff on chloranilines and chlomitranilines, and the 

 minutes of the meetings of the Society. 



The new French cable for America has been placed at the 

 disposal of the public for correspondence. It goes direct from 

 Brest to St. Pierre, and from St. Pierre to Massachusetts, 

 where it is connected with the American Telegraphic Union. 

 A new cable will be laid from Brest to Penzance by the Faraday 

 steamer, in the beginning of February, and afterwards from 

 Penzance to St. Pierre. This second cable will be used for 

 English telegrams. 



It is stated that a valuable bed of anthracite has been pro- 

 spected at Ching-men-chow, near Ichang on the Upper Yangtszi- 

 kiang, and that it is already being worked. The coal district is 

 : aid to extend for seventy-five square miles, and to contain ten 

 beds of coal, one of which, at Wo-tsze-kow, is estimated to 



contain 1,200,000 tons, and lying only 100 feet below the 

 surface. 



The Cracow newspaper Witk states that the Cracow Academy 

 proposes to convoke a general congress of historians. 



The Forty-sixth Annual Report of the York School Natural 

 History Society is on the whole favourable ; good work has been 

 done in the geological section especially. 



The annual meeting of the Yorkshire Naturalists' Union was 

 held at Huddersfield on Saturday week, Dr. II. C. Sorby, the 

 president, occupying the chair. There are now twenty-six 

 societies in the Union ; Prof. Williamson, of Manchester, was 

 chosen as Dr. Sorby's successor in the presidency. The latter 

 gave his annual address in the evening on "The Structure and 

 Origin of Limestones." 



We have received a report of a very successful scientific exhi- 

 bition which has been opened for a few days by the enterprising 

 Dundee Naturalists' Society. We notice from the programme 

 of the Society, that besides lectures by eminent men of science, 

 a number of papers of a thoroughly scientific character, will be 

 read by members of the society during the present session. 



A BANK, commonly called Hafner, in the Lake of Zurich, and 

 sitiiated at a distance of a few thousand feet from the Mansion 

 House Promenade, is now being minutely investigated by ordar 

 of the town authorities. It appears that remains of a prehistoric 

 pile dwelling are coming to light at this spot, consisting of a 

 quantity of coarse and fine clay vessels, coals, a few bronze 

 implements, &c. The piles upon which the old colony re.ted 

 are particularly numerous. 



The additions to the Zoological Society's Gardens during the 

 past week include a Chinese Rhesus Monkey (Macacus lasiotus) 

 from Shanghai, presented by Messrs. John Morris and A. H. 

 Brown ; two Blue-eyed Cockatoos (Caca'.ua opthalmicd) from 

 the Duke of York's Island, presented by the Rev. Geo. Brown, 

 C.M.Z.S. ; two Martinican Doves (Zenaida martinicana) from 

 Grenada, W.I., presented by Capt. H. King; a Kittiwake Gull 

 (Rissa tridactyla), European, presented by Mr. W. H. Cope, 

 E.Z.S. ; a Common Barn Owl (SIrix flammea), European, pre- 

 sented by Mr. G. D. Edwards; a Jaguar (Felis onfa) from 

 South America, four Common Peafowls (Puvj cristata) from 

 India, two Knots (Tringa canutus), four Widgeon (Maraapent- 

 lope), a Wild Duck (Anas bjschas), two Scaup Ducks (Fnl^ula 

 marila), European, | urchased. 



OUR ASTRONOMICAL COLUMN 

 Periodical Variation in the Brightness of Nebul.e. — 

 In 1877, in a communication to the Royal Astronomical Society, 

 Prof. Winnecke drew attention to the nebula H. II. 278, re- 

 marking tbat it appeared to exhibit not only a variability in its 

 light, but, which he considered much more remarkable and diffi- 

 cult of explanation, tbat periodical fluctuations of brightness 

 seemed to take place. A .short time since he briefly pointed out 

 a second case of similar character, in the nebula H. I. 20 ; in 

 the last number of the Astronomische Kachruhten he returns to 

 the subject, and collecting the descriptions of the latter nebula, 

 presents very strong evidence of the variability of its light and 

 indications that it may prove periodical. 



H. I. 20 is No. 8S2 A, and No. 2405 of the General Cata- 

 logue : its position for 1SS0 is in R.A. 1 ill. 18m. 13s., N.P.D. 

 77" 59' '6, or it precedes B.A.C. 3S82 by 34'5s., and is 5' south 

 of the star. A star 12m. follows at 2'8s., 2'"I to the north. Sir 

 W. Herschel described it as " very bright" on March 15, 1785. 

 Forty-five years afterwards his son found it " extremely fainti" 

 and remarked at the time: "This nebula must have changed 

 greatly, if it ever belonged really to the 1st class." On April 4, 

 1831, he again found it faint. The next record of its appear- 

 ance wis made by Boguslawskr, during his preparation of Hour 

 XI. of the Star-charts of the Berlin Academy, when it appears 



