June 29, 1893] 



NATURE 



207 



According to Block, this is due to a sudden sharp frost, which 

 freezesilhe river to the bottom at a shallow place without allow 

 ing time for the formation of mere surface ice. It is probable 

 that a strong east wind is a necessary condition, and that the 

 detention of the water is aided by the reeds growing near the 

 datflow of the lake. A collection of records of the occurrence 

 has been made by Herr Robert Sieger in a paper on the oscil- 

 lations of lake and ocean levels in Scandinavia, which appears 

 in the Zeilschnft der GeseUschaft fiir Erdkundc. He finds six 

 observations during the sixteenth, twelve during the seventeenth, 

 and eighteen in the eighteenth century. He does not, how ever, 

 think that the general level of the lake is perceptibly influenced 

 by the phenomenon. 



Two organisms resembling the cholera bacillus have re- 

 cently been obtained by Bujwid from water during an outbreak 

 qf cholera (" Ueber zwei neue Arten von Spirillen im Wasser," 

 Centralblatt fiir Bakteriologic, vol. xiii. 1893, p. 120). 

 These are designated as Bacillus chohroides a. and ^ in conse- 

 quence of their striking resemblance to Koch's cholera organ- 

 ism. It is quite possible, however, that these forms may really 

 be identical with the original cholera spirillum, and that the 

 differences noted in cultures and microscopic specimens miy be 

 simply due to the modifications undergone by the latter after 

 long residence in artificial culture media. Finkelnburg ("Zur 

 Frage der Variabilitiii der Cholera bacillen," ibid. p. 113) has 

 made careful comparalive studies of cholera bacilli obtained 

 from different centres during the recent cholera epidemic. He 

 found ihat whereas those obtained from Paris and Hamburg 

 respectively were practically identical, they presented .slight 

 but distinct deviations from the laboratory specimen of Koch's 

 spirillum originally brought from India. Finkelnburg points out 

 as the result of his investigations that in the course of the many 

 years during which this organism has been cultivated outside the 

 human body and in foreign surroundings, it has apparently 

 undergone a gradual attenuation, and that in this process of 

 degeneration it has lost some of its vital energy. Whether it 

 has also suffered a diminution in its toxic properties Finkeln- 

 burg has not yet determined, but concludes by emphasising the 

 imporlance of such an inquiry as calculated to throw some light 

 on ihe possible future attenuation of the virus during its residence 

 in Europe. 



Mr. F. C. Selous, who has spent twenty years in South 

 Central Africa, has now completed the book in which he de- 

 scribes his experiences in the country. Messrs. Rowland Ward 

 ind Co. will publish the work in the autumn. 



A BOOK by Capt. Hayes on " The Points of the Horse," and 

 dealing chiefly with equine conformation, will be published next 

 month by Messrs. Thacker and Co. 



The trustees of the South African Museum have issued their 

 report for the year 1892. Mr. Roland Trimen, F.R.S., the 

 curator of the museum, reports favourably of the condition of 

 the collec:ion generally. The donations amount to 4857 

 specimens, presented by 90 donors, as 'against 4677 speci- 

 mens presented by 105 donors in the year 1891. For a long 

 time extended accommodation has been needed, and we are 

 glad to note that the Parliament granted the application for a sum 

 of /20,ooo to satisfy the want. Designs for the new museum 

 building have been invited, and the work will be proceeded 

 with as soon as possible. 



. The proceedings of the Bith Natural History and Anti- 

 quarian Field Club, No. 4, contains an article by the Rev. H. 

 H. Winwood, on some deep-well borings made in Somerset and 

 one or two other counties. A description is given of the thick- 

 iiess and nature of the beds pierced in each case. 

 NO 12-^5, vor.. /i8"l 



' The second part of " Phycological Memoirs," being researches 

 made in the botanical department of the British Museum, con- 

 tains, among other papers, several notes on the morphology of 

 the Fucacea;. Mr. George Murray contributes a comparison of 

 the marine floras of the warm Atlantic, Indian Ocean, and the 

 Cape of Good Hope. 



A SERIES of monographs dealing with the principal gold fields 

 of Victoria are being prepared under the direction of Mr. A. 

 W. Howitt, the Secretary for Mines. A report by Mr. E. J. 

 Dunn, on the Bendigo gold-fields, forms one of the number. 

 According to Mr. D.inn, the primary features of this gold-field 

 are that the mass ofsilurian strata which he investigated is made 

 up of bands auriferous to varying degrees or barren of gold, and 

 that the whole of the strata are bent along certain lines into 

 anticlinal folds with intervening synclinals. The report is 

 illustrated by numerous plans, sections, and diagrams. 



The Scientific Society of the University College of Wales 

 has issued its first report. Natural history specimens collected 

 during the excursions have been identified, and the results 

 recorded in the report furnish some useful information with 

 regard to Welsh fauna and flora. . , 



At the meeting of the Russian Chemical Society fn March 16 

 K. D. Khroushchoff, who is well known for his remarkable 

 synthesis of hornblende and other minerals, made a communi- 

 cation to the effect that he also has obtained artificial diamonds 

 in a way similar to that of Moissan. He prepared a carbonide of 

 silver, Ag.^C, obtained fay the heating of cumina'.e of silver. At 

 the te.tiperalure of boiling, silver absorbs about six per cent, of 

 carbon, which is given out on cooling. Cooling was effected 

 rapidly, as l)y Moissan, so that a crust was formed which pre- 

 vented the increase of volume of the metal, an<l produced a con- 

 siderable interior pressure. It app'eared that part of the dis- 

 sociated carbon had the properties of diamini — ihe dust con- 

 sisting of minute broken crystals and laminje, colourless and 

 transparent, strongly refracting light, quite isotropic, and 

 scratching corundum ; on combustion they give carbon dioxide, 

 with an insignificant amount of ash. Diamond dust obtained 

 in this way was shown to Prof. Beketolf the day after 

 Moissan's communication had been received at St. Petersburg. 



Further interesting experiments with the electric furnace 

 are described by M. Moissan in the current number of the 

 Comptes Rendus. By attaching to the furnace a condensing 

 tube of copper shaped like the letter U, and so constructed as 

 to be surrounded by an outer jacket of cold water constantly 

 changing under high pressure, M. .Moissan has been enabled to 

 distil and condense most of the elements which have hitherto 

 been found so refractory. When a piece of metallic copper 

 weighing over a hundred grams was placed in the inner crucible 

 of the furnace and subjected to the arc furnished by a current 

 of 350 amperes, brilliant flames shot forth from the apertures 

 through which the carbon terminals were inserted. The flames 

 were accompanied by copious yellow fumes, due to the com- 

 bustion of the issuing vapour of copper in contact with the 

 oxygen of the air. After the expiration of five minutes nearly 

 thirty grams of copper had been volatilised. Under the cover 

 of the furnace an annular deposit of globules of metallic copper 

 was found, and upon examination of the condensing tube a large 

 proportion of the volatilised copper was discovered condensed 

 in almost a pure state. It has long been known that silver is 

 volatile ; it is now found that at the temperature of an arc of 

 the above description silver may be brought to full ebullition in 

 a few moments, andit distils with ease, condensing in the copper 

 condenser in the form of small globules, whose size varies from 

 that of small shot to spherules of microscopic dimensions, and 

 a certain proportion is usually deposited in the form of arbores- 



