December 7, 191 1] 



NATURE 



189 



tute on November 29. In the course of his address 

 Suhnan pointed out that the dominant thought 

 rh impressed one to-day was the many-sidedness, the 

 increasing scope, and the intense vigour which now marks 

 metallurgical progress. Tiie interaction of associated 

 sciences is now beginning to play its part in the develop- 

 ment of metallurgical industries. Certain of the factors of 

 so-called molecular energy find expression in some of the 

 jiewer processes and phenomena of metallurgy, as shown 

 in the methods adopted to the harnessing of molecular 

 attractions which reside upon the surfaces of solids, to the 

 purposes of ore concentration. These methods, which 

 [have, for example, completely changed the economic out- 

 look of the great Broken Hill deposits of silver-lead-zinc 

 Ores, are there used to separate the blends constituent in 

 saleable form from the " tailings " left behind after the 

 bulk of the lead and silver have been recovered. But they 

 arc applicable, in general, to all sulphide ores, as well as 

 to finely divided metals and non-metals, such as gold, 

 graphite, carbon, diamond, sulphur, and so on ; and they 

 are frequently spoken of as " oil processes," from the fact 

 that in several of them oil is used in larger or smaller 

 quantities, usually in smaller. In such processes there are 

 no chemical reactions to speak of ; physical forces of 

 previously unsuspected range and power, so far as com- 

 mercial applications are concerned, have been induced to 

 do the work more easily and much more economically, the 

 force mainly concerned being what is called " surface 

 energy." Equally new, and probably of great importance 

 to the metallurgist of the future, are the developments in 

 colloidal chemistry. The plasticity of clays and " ultra- 

 sliminess " of " slimes " are due to this class of bodies, in 

 which inorganic materials ape the reactions of organic; a 

 r!n\' colloid may almost be said to masquerade as a fatty 

 Mr. Sulman also referred to the extended applica- 

 of improved magnetic and electrostatic methods for 

 the separation of dry ores, and to catalytic processes of 

 metallurgical importance. 



A SELECTED " List of Educational Books for Schools, 

 Colleges, and Self-tuition," issued by Messrs. VV. and G. 

 Foyle, 135 Charing Cross Road, London, W.C., has 

 reached us. Nearly all the books included in the catalogue 

 can be supplied secondhand at half the published prices ; 

 and Messrs. Foyle will send any book in stock on 

 approval. 



Messrs. William Weslev and Son, 28 Essex Street, 

 London, W.C., have sent us a copj* of the latest issue of 

 their " Natural History and Scientific Book Circular." 

 It contains a catalogue of 356 selected books on natural 

 history, with coloured illustrations, followed by a list of 

 works published by, or on sale with, Messrs. Wesley and 

 Son, who are, it may be added, agents for the Smithsonian 

 Institution and the U.S. dovernment departments. 



Messrs. J. Wheldon .and Co. (38 Great Queen Street, 



i' :;sway, W.C.) have just issued a supplement to their 



tific and geological catalogues. The supplement com- 



, prises recent purchases in astronomy, chemistry, geology, 



I palaeontology, mineralogy, mining, &c.. and includes a 



!' small collection of works on applied chemistry, metallurgy, 

 and other subjects. 



I Erratum. — We are asked to state that in the abstract of 

 I Mr. Hutchinson's paper read before the Mineralogical 



! Society (p. 165) the temperature at which gypsum becomes 

 optically uniaxial should be 95" C, not 25° C. The 

 incorrect value was given in the typewritten report re- 

 ceived by us, and the error was not corrected in the proof 

 JRubmitted and returned to the printers. 



NO. 2197, VOL. 88] 



OUR ASTRONOMICAL COLUMN. 

 Discovery of a New Comet, 191 i7i. — A telegram from 

 Kiel announces the discovery of a new comet by M. Schau- 

 masse, at Nice, on November 30. Its position at 

 ijh. i5-9m. (Nice M.T.) was 



R.A.= i3h. 12.2m., dec. =5° 51' N., 

 and its daily motion was found to be -i-3m. 32s. in R.A. 

 and —13' in declination; the magnitude is 12-0. 



A second telegram gives an observation by Dr. Abetti at 

 Arcetri on December 2, the position at i7h. 26-9m. 

 (Arcetri M.T.) being 



R.A. = i3h. 19m. 17.6s., dec. = 5° 24' 29" N. 



The comet is thus seen to be moving in a south-east 

 direction through Virgo. 



Borrelly's Comet, igiie. — Borelly's comet, rediscovered 

 by Mr. Knox Shaw on September 19, is approaching both 

 the sun and the earth. As the perihelion passage will take 

 place on December 18, when the comet is nearly in opposi- 

 tion with the sun, and as the comet is moving northwards 

 rapidly, it may become visible with opera-glasses during 

 the latter part of December and in January, 1912 (L'Astro- 

 nomie, November). 



The Production of Star Streams. — A paper by Prof. 

 Benjamin Boss, in No. 629 of The Astronomical Jourual, 

 discusses, in relation to a star stream he has found among 

 seventy-one large proper-motion stars given in the Pre- 

 liminary General Catalogue, the somewhat startling sug- 

 gestion that community of direction and velocity in such 

 streams may be caused by the initiation and maintenance 

 of their motions in an electromagnetic field of universal 

 extent. 



The directions and proper motions of eleven of these 

 large proper-motion stars, together with their radial veloci- 

 ties and parallaxes where available, agree so well as to 

 preclude the idea of chance occurrence, and some physical 

 explanation is sought. 



Assuming that the stars form from nebulae, the motion 

 of the latter might explain the phenomena ; but the ex- 

 tended nebulae do not exhibit such mottis pectiliaris, and 

 Prof. Boss seeks the common cause elsewhere. 



The suggestion is that the nebulae are the seat of 

 tremendous ionisation forces producing segregation, and 

 electromagnetic polarities in the segregated masses. In 

 the course of time a relatively strongly polarised mass 

 becomes expelled from the matrix and commences a stellar 

 existence. Initially the directions would be haphazard, 

 but the action of the supposed universally existent electro- 

 magnetic field would be to swing the polarised masses into 

 paths along the approximately parallel lines of force. 

 Assuming the B-type stars to be the newest. Prof. Boss 

 finds support in the fact that such stars display random 

 motions, while those in his group of large proper-motion 

 stars, exhibiting community of direction, are of the types 

 F, G, and K. Further, the action of a constant accelera- 

 tion such as is suggested would tend to level up the differ- 

 ences found in the initial velocities, thus producing the 

 community of velocity observed. 



Double-star Measures. — In No. 4534 of the Astro- 

 nomische Nachrichten Prof. Burnham publishes a long list 

 of recent measures of double stars related largely to the 

 proper motion of stellar systems contained in his General 

 Catalogue. The measures were made with the 40-inch 

 refractor at the Yerkes Observatory, and follow on Prof. 

 Burnham's similar publications in the same journal. 



In No. 4537 Herr J. Voiite publishes a si-.-ond list of 

 double-star "measures, which will later h- |niblished 

 in cxtcnso in the .Annals of Leyden Observatory. 



Radial Velocity of a Cygni.— Some time ago w.- 

 directed attention to a result obtained by Prof. Belopolsky 

 and Mr. Neuimin in which they found what appeared to 

 be a real difference between the radial velocity of a Cygni 

 as determined from the metallic lines and that determined 

 from the hvdrogen and helium lines. At the suggestion of 

 Prof. Frost, Mr. O. J. Lee has examined some measures 

 III ihr spectrum made by him in 1910, and he fails to find 

 .in\ K.iifirmation nf tlir Pulkowa results. He suggests 

 ili.ii \\\r- discrepam \ fuiml by Neuimin and Belopolsky 



