November 7, 1907] 



NA TURE 



producing insects. It contains, in particular, an accuuTt 

 of a little-known pamphlet by Dr. Friedel (Leipziaf, I70i). 

 a man who, as the authors point out, was possessed of 

 the true scientific spirit, but who appears to have corrected 

 the blunders of Leewenhoek only to make lesser blunders 

 of his own. 



The Rendiconto of the Bologna Academy for 1905-6 

 has been recently issued. It contains papers by Prof. 

 Guido Tizzoni and Dr. A. Bongiovanni on the curative 

 action of radium on the virus of rabies, together with a 

 short communication on the same subject by Prof. Ivo 

 Xovi, who seems to have arrived at somewhat different 

 conclusions regarding the efficacy of the cure. In 

 addition, Prof. Cesare Arzella discusses in two short notes 

 the conditions of integrability of a series of integrabic 

 functions and of partial differential equations respectively. 



From Captain Lyons's report of the Survey Department 

 of Egypt in 1906, it appears that the two principal features 

 of the work during the year were the completion of the 

 cadastral survey (large-scale plans of the cultivable land 

 of Egypt, on which the individual holdings are indicated), 

 and the publication of about one-quarter of the general 

 map of the Nile valley and the delta on the scale of 

 I : 50,000. The work of the meteorological section has 

 greatly increased ; among many improvements we may 

 mention that since January, 1906, monthly summaries of 

 the weather have been prepared and published, and that 

 subsequently the area of the Daily Weather Report has 

 been enlarged to include pressure and wind data over the 

 eastern Mediterranean and Nile basin, thus filling up an 

 important gap in the regions for which weather conditions 

 are mapped daily. 



The September part of the Journal of the Insiitution of 

 Electrical Engineers contains a paper by Mr. E. \V. Moss in 

 which, under the title "Electric Valves," short accounts 

 are given of the theory and modes of action of many of 

 the devices used at present for converting alternating into 

 direct currents. Of these, the Norden electrolytic valve 

 and its modifications appear to have proved themselves 

 most capable of dealing with heavy currents, while the 

 glow-lamp valve of Dr. Lee de Forest and Prof. Fleming 

 seems one of the most convenient for the small currents 

 used in wireless telegraphy. 



Our knowledge of the electrical state of the atmosphere 

 should in the near future receive considerable additions 

 from the observations which, according to the June number 

 of Terrestrial Magnetism and Atmospheric Electricity, are 

 about to be taken on board the United States magnetic 

 survey yacht Galilee during her cruise in the Pacific and 

 by the staff-surgeons on board two of the vessels of 

 the German Royal Navy. The potential gradient, the 

 conductivity of the air. and the radio-activity of air and 

 sea-water are all to be measured regularly during calm 

 weather. 



Crystallised alumina occurs in nature in varyijig shades 

 of colour, ranging from the colourless sapphire to brown 

 and opaque corundum. The ruby, sapphire, and oriental 

 amethyst are varieties distinguished by their transparency 

 and colour. These colours have been attributed 10 the 

 presence of traces of salts of iron, manganese, chromium, 

 titanium, and other metals, but the experiments described 

 by M. F. Bordas in the current number of the Comptes 

 rendus (No. 18, October 28) would appear to prove that 

 this explanation is insufficient, since by submitting a 

 coloured stone to the action of a highly active radium 

 bromide the colour is modified, passing from red through 



NO. 1984. VOL. yyl 



violet, blue, and green to yellow. Radium bromide of an 

 aclivity of 1,800,000 was used in these experiments, the 

 time of exposure not being stated. The action could be 

 modified by graduating the activity of the radium salt or 

 by increasing the distance of the stone from the radio- 

 active material. The stones thus treated are not radio- 

 active ; they do not light up in the dark under the influence 

 of pure radium bromide, and the coloration is permanent 

 as regards heating. 



Dr. W. Doberck has retired from the position of 

 director of the Hong Kong Observatory, and has been 

 succeeded by Mr. F. G. Figg. He desires it to be known 

 that his permanent address is now " Knowloon," Elgin 

 Road. Sutton, Surrey. 



Under the title of "A Chronicle of Science," the 

 Graphic publishes fortnightly articles which deal attrac- 

 tively and accurately with topics of scientific interest. The 

 issue of October 19 contained an illustrated description 

 of the Percy Sladen Trust Expedition to the Indian Ocean, 

 and the current number (November 2) includes portraits of 

 Sir John Evans and the Rev. W. H. Egerlon— the 

 " father " of the Geological Society. Sir John Evans will 

 celebrate his eighty-fourth birthday on November 17, and 

 Mr. Egerton his ninety-sixth on November 13. Mr. 

 Egerton was elected a Fellow of the Geological Society in 

 1832, and has therefore been on its roll for seventy-five 

 j'ears. 



Among new books shortly to be issued are to be 

 noted:— "The Functional Inertia of Living Matter," by 

 Dr. D. Eraser Harris; "A Manual of Prescribing," by 

 Dr. C. R. Marshall; and a revision of " Waring's Bazaar 

 Medicines of India," by Lieut. -Colonel C. P. Lukis, 

 I. M.S. Messrs. J. and A. Churchill will publish these 

 three books. 



A NEW edition of Mr. Wm. Woods Smyth's "The Bible 

 in the Full Light of Modern Science " has been published 

 by Messrs. Simpkin, Marshall and Co. Much new matter 

 has been added. The price of the book is is. 6d. net. 



Mr. Carl Zeiss, of Jena (London address, 29 Margaret 

 Street, W.), has published in brochure form full particulars 

 of the field glasses he is prepared to supply. It is con- 

 venient to have in this concise form details as to price, 

 linear magnification, and so on of these widely used 

 glasses. 



Erratum. — In Prof. Rutherford's letter in Nature of 

 last week (October 31, p. 661, col. 2, line 23), for 

 " picradium " read " preradium." 



OUR ASTRONOMICAL COLUMN. 



Comet Mellisii (1907^). — Observations of comet 19074? 

 made at the Lyons Observatory on October 17 showed 

 that the object liad the appearance of a diffused nebulosity 

 of about 35" diameter, was of about the tenth magnitude, 

 and had a slight central condensation. Observing at the 

 Marseilles Observatory on October 17 and 18, M. Borrelly 

 found the comet to be fairly bright and extended, with a 

 granular appearance {Comptes rendus, No. 17, October 21). 



Other observations are recorded in No. 4210 of the 

 Astronomische Nachrichten (p. 163, October 28), in which 

 Herrn G. van Biesbroeck reports that on October 19, 

 using the 15-inch refractor of the Uccle Observatory with 

 a magnification of 240, he saw the comet as a circular, 

 nebulous object of i ' diameter and of the tenth magni- 

 tude. A central condensation, but no stellar nucleus, was 

 seen. 



Prof. Becker, director of the Strassburg Observatory, 



