July 12. 1894] 



NA TURE 



261 



sity of Glasgow, James Robert Erskine-Murray ; by the 

 University of Aberdeen, William Brown Davidson ; by 

 University College, Bristol, Reginald Charles Clinker ; by 

 Yorkshire College, Leeds, Frankland Dent ; by University 

 College, Liverpool, Alfred James Ewart ; by University College, 

 London, David King Morris ; by Owens College, Manchester, 

 Julius Frith ; by Durham College of Science, Newcastle-on- 

 Tyne, Robert Beattie ; by University College, Nottingham, 

 William Beckit Burnie ; by Queen's College, Galway, John 

 Alexander M'Clelland ; by the University of Torcrto, Frank 

 Boteler Kenrick ; by Dalhousie University, Halifax, Nova 

 Scotia, Frederick James Alexander M'Kittrick. 



The President and Council of the Royal Society have, upon 

 the recommendation of the Joule Studentship Committee, 

 elected Mr. J. D. Chorlton, of the Owens College, to the first 

 Joule Studentship. This studentship was founded for the pur- 

 pose of enabling students to carry on certain researches on lines 

 laid down by Dr. Joule, more especially with the view of deter- 

 mining the constants of some of the instruments employed 

 by him, which his representatives can place at the student's 

 disposal. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, May 31. — "The Root of Lyginoiendron 

 Oldhamiiiin, Will." By Dr. W. C. Williamson, F.R.S., and 

 Dr. D. IL Scott. 



During a re-investigation of the structure ai Lyginodendron,^ 

 the results of which the authors hope to lay before the Royal 

 Society on a future occasion, an important fact has come to 

 light, which they place on record without delay. 



A carboniferous fossil, with the structure perfectly preserved, 

 has been described in previous memoirs, under the name of 

 Kaloxylon Hookcri, Will." The authors have now established 

 the fact th.at Kaloxylon was not an independent plant, but was 

 the root of Lyginodendron Oldkamiuin, 



Specimens, presenting in every respect the typical Kaloxylon 

 structure, have been found in actual continuity with the stem of 

 /.yi^iiodindron, arising from it as lateral appendages. Their 

 structure and mode of origin prove that they were adventitious 

 roots. These organs branched freely, and the authors have 

 found roots and rootlets of all sizes, and at all stages of 

 development. 



This discovery enables a complete account to be given of the 

 vegetative organs of Lyginodendron, as they are now fully 

 acquainted with the structure, not only of the stem and foliage, 

 but also of the adventitious roots. 



June 14. — "On a Method for determining the Thermal 

 Conductivity of Metals, with Applications to Copper, Silver, 

 Gold, and Platinum." By James H. Gr.iy. 



The object of this investigation was to obtain a method for 

 determining thermal conductivities of metals, which would not 

 require either elaborate preparations or large quantities of the 

 substances to be tested, and by means of which a test could be 

 made in a few hours. 



The essence of the method is to keep one end of a given 

 length of the wire at a constant known temperature, and to 

 measure the rise of temperature of the other end of the wire every 

 minute. If proper precautions be taken to prevent loss by 

 radiation from the sides, the data are obtained for calculating 

 the thermal conductivity. 



The wire to be tested is soldered at one end into the bottom 

 of a copper box. The diameters found most convenient were 

 from 2 to 4 mm., the lengths from 4 to 8 cm. 



The box is filled with water and supported at its middle by 

 being fitted into an asbestos-lined wooden screen, 24 x 24 cm. 

 3 mm. length of the other end of the wire is soldered into a solid 

 copper ball, diameter 5 -5 cm. In the ball a hole 3 cm. deep is 

 made, so as to admit the bulb and part of the stem of a small and 

 very sensitive thermometer. This thermometer is graduated 

 from 5'C. to 20° C, and can easily be read to within one- 

 fortieth of one degree. The bulb is surrounded by water. 



1 Cf. \VilIi.-imson, " On the Organisation of the Fossil Plants of the Coal 

 Measures." Pan IV. Phil. Traits. 1873, p. 377 ; Part XVII. Phil. 

 Tram iSgo, B. p. 89. 



2 Cf. "'On ihc Organisation of the Fossil Plants of the Coa! Measures." 

 Part VII. Phil. Trans. 1876, Part 1, p. i ; Part XIII. !/'/ii7. Trans. 

 1887, B. i>. 289. 



NO. 1289, VOL. 50I 



All the probable errors are practically tested by using different 

 lengths or diameters of the wire, and the results obtained in 

 the present investigation indicate that the errors have been 

 eliminated. 



In order to make a complete test of a metal it is only necessary 

 to take a wire of 5 or 6 cm. length and solder it firmly, the one 

 end into the bottom of the heating box, the other into the 

 calorimeter ball. The water in the heating box is kept boiling 

 briskly, and readings are taken every half-minute from the 

 thermometer in the ball. These readings are then put upon a 

 curve as ordinates, with the time in minutes as abscissae. From 

 this curve the rise of temperature per unit time can then be 

 accurately read off, and, the thermal capacity of the ball being 

 already determined, the flow of heat per unit time is obtained. 



At the beginning of the experiment the ball is cooled to about 

 6" or 7' C. below the temperature of the air, and the rise for equal 

 temperatures above and below that of the air taken, the radiation 

 being thus eliminated. 



The metal which was chiefly used for the exhaustive tests of 

 the method was copper wire, of diameter 02 1 cm., density 8*85, 

 volume specific (electrical) resistance at about 13° C. 1834 in 

 absolute units. 



It must be noted that the found values are the means of the 

 conductivities corresponding to the temperatures at the ends of 

 the wire. When compared with the values obtained by other 

 experimenters, the results of the latter must be taken for the 

 mean of 97° C. and 10° C, that is, 53° C. 



For this temperature Angstrom gives 0*9208. 



Several qualities of copper were tested, as well as pure gold, 

 silver, and platinum, kindly lent for investigation by Messrs. 

 Johnson, Matthey, and Co. 



The values are given below : — 



Mean Conductivity between Temperatures 10° C. and 97' C. 



Copper, Specimen 



Silver 



Gold 



Platinum 



(pure) 



"Flame Spectra at High Temperatures. Part III. 

 The Spectroscopic Phenomena and Thermo-Chemistry of the 

 Bessemer Process." By Prof. W. N. Hartley, F.R.S. 



The flame issuing from the mouth of a Bessemer converter 

 was first investigated by Sir Henry Roscoe ' in 1863 ; by Lie- 

 legg," and by Marshall Watts in 1867;-' by Tunner,« J. M. 

 SiUiman, Rowan,'' Von Lichtenfels," Spear Parker," Kupel- 

 wieser,' Brunner,'' and Wedding in tS68 ; '" also by A. Greiner 

 in 1874." 



Up to the present time the precise nature of the spectrum, 

 the cause of its production, its sudden disappearance when 

 decarburisation of the metal takes place, and the connection 

 between the decarburisation of the metal and the extinction of 

 the spectrum have not been satisfactorily explained. According 

 to Roscoe, Lielegg, Kupelwieser, and Spear Parker, the 

 spectrutn is characterised by bands of carbon or of carbon 

 monoxide, which disappear when all carbon is burnt out of the 

 metal. 



On the other hand, the investigations of Simmler,'- Brunner, 

 V^on Lichtenfels, and Wedding, the spectrum is not due to 



i Literary and Phil. Soc, Manchester, Proc, vol. 3, p. 57, and Phil. 

 Mag;.., vol. 34, p. 437- 



'-' .Sitznngsberichte Kaiscrl. Akademie iter Wissenschaften, Wien, vol. 

 56, Part ii. 



s Phil. Mag., vol. 34, p. 437- 



< Dingier s Polytcch. /., vol. 178, p. 465. 



■'' Pliil. Mag., vol. 41, p. I. 



'» Dingier s Polytech. J., vol. tgi, p. 913. 



r Chent. .Ve-MS, vol. 23, p. 25. 



8 Ocsternichiscttc Zcitschr. fur Berg- und Hflllen-lVesen, No. 3, p. 59, 



1868. 



» Loc. cit.. No. 29, p. 327, '863. 



!» Zeilschrift far das Berg HIitten- und Salinen-Wesen, vol. 37, p. 117, 

 1869. 



'1 RcT'UC Universelle, vol. 35, p. 623. 



1- Zcitsclir. fur Anaiytischc Clumic, 1862. 



