238 



NA TURE 



[July 7, 1898 



measurement of the emissivity of platinum and palladium at 

 their melting points. 



The platinum wire, which served at the same time as radiator 

 and thermometer, waso"ii2 cm. in diameter. It was placed 

 in the axis of a vertical glass cylinder, which formed the 

 enclosure. 



The effect produced by a change in the size, shape, material, 

 and temperature of the enclosure and in the position and 

 diameter of the wire are also studied. 



The temperature is expressed in degrees Centigrade, and the 

 emissivity in C.G.S. units. 



Part ii. consists of a bolometric study of the radiation 

 emitted by platinum at temperatures ranging from 500" C. to 

 the melting point of the metal. It is shown that for theoretical 

 reasons the true rate of change of the total radiation with 

 temperature lies between the values obtained by measuring the 

 heat lost by the radiating body and those deduced from the. 

 readings of any form of bolometer or thermopile. 



By comparing the observations of Dr. J. T. Bottomley and 

 Schleiermacher, based on the first method, with those of F. 

 Paschen and of the author, made by the second method, a 

 criterion is obtained by which to test any formula intended to 

 express the law of thermal radiation. 



The formulas of Dulong and Petit, of Stefan, and of Rosetti 

 fail when tested in this manner ; whilst Weber's formula, from 

 400° to 800" C, gives results in close agreement with the true 

 rate of change of total radiation with regard to temperature. 



The second part of the paper also contains a description of 

 some points of interest in the design of the bolometer which 

 was used during this work. 



Part iii. refers to the variation of the intrinsic brilliancy of 

 platinum surface with temperature. 



The results may be expressed by the following formula : — 



(/ - 4C30) 



•67^ 



where / is the temperature in degrees Centigrade, and /5 the 

 intrinsic brilliancy in candle power per square centimetre. The 

 constant 400 is taken as the temperature limit at which the 

 visible radiation falls to zero. 



Chemical Society, June 16.— Prof. Dewar, President, in 

 the chair. — The following papers were read : — Preparation of a 

 standard acid solution by direct absorption of hydrogen chloride, 

 by G. T. Moody. The author prepares an accurately standardised 

 solution of hydrogen chloride by determining the increase in 

 weight consequent on absorbing the pure gas in water. — Re- 

 searches on the terpenes. III. Halogen derivatives of fenchene 

 and their reactions, by J. A. Gardner and G. B. Cockburn. An 

 o- and a jS-chlorofenchene hydrochloride are obtained by treat- 

 ing fenchene with phosphorus pentachloride ; both readily yield 

 a crystalline chlorofenchene CjoHjgCl, which can be converted 

 into a chlorofenchenephosphonic acid. — Researches on the terp- 

 enes. IV. On the oxidation of fenchone, by J. A. Gardner 

 and G. B. Cockburn. Fenchone is very slowly oxidised by hot 

 nitric acid with formation of isocamphoronic acid, dimethyltri- 

 carballylic acid, dimethylmalonic acid, isobutyric acid, acetic 

 acid, and nitrofenchone. — Nitrocamphor and its derivatives. 

 Part I. Isodynamic forms of nitrocamphor, by T. M. Lowry. 

 Although solutions of nitrocamphor show multirotation the 

 author has not been able to isolate the isodynamic forms of the 

 constitutions 



/CH.NO2 /C^N.OH 



CsHi/l andC8H/|\i , 



\co \c ^ 



yet the corresponding forms of t o'-bromonitrocamphor seem to 

 exist.— Cannabinol, by T. B. Wood, W. T. N. Spivey and T. 

 H. Easterfield. Cannabinol is a mixture which yields a liquid 

 and a crystalline acetyl-derivative, CjiHagOa.— An improved 

 form of gas-analysis apparatus, by W. A. Bone.— Preliminary 

 note on the action of light on acetylene, by W. A. Bone and 

 J. Wilson. On exposing acetylene to sunlight a greasy brown 

 deposit is formed which is still under examination.— Reversible 

 zymohydrolysis, by A. C. Hill.— The solubility of isomeric 

 substances, by J. Walker and J. K. Wood. The authors find 

 that the rule that the order of solubility of isomerides is inde- 

 pendent of the solvent is not strictly applicable. —Note on 

 nitration and substitution in nitro-compounds, by A. Lapworth 

 and C. Mills.— Hydroxydibromocamphorsulphonic acid. A cor- 

 NO. 1497, VOL. 58] 



rection, by A. Lapworth and F. S. Kipping. — Enantiomorphism, 

 by F. S, Kipping and W. J. Pope. — Azobenzene derivatives of 

 chrysin, euxanthone, gentisin and morin, by A. G. Perkin. 

 Chrysin yields a disazo-derivative of the composition CigHgO^ 

 (N2Ph)2 ; similar compounds have been prepared from other 

 analogous colouring matters. — Constituents of the Indian dye- 

 stuff " waras," by A. G. Perkin. Waras, a purplish powder 

 covering the seed pods of Flemingia congesta, contains flemingin, 

 C12H12O3, homoflemingin and two resins CuHijOjand C13H14O3 ; 

 it dyes silk a golden yellow shade. — Note on the oxidation of 

 charcoal by nitric acid, by G. Dickson and T. H. Easterfield. 

 By a process involving oxidation with fuming nitric acid and 

 potassium chlorate, charcoal may be made to yield one-fourth 

 of its weight of crystalline ammonium mellitate. 



Zoological Society, June 21. —Dr. W. T. Blanford, F.R.S., 

 Vice-President, in the chair. — Mr. J. Graham Kerr exhibited 

 some specimens of Lepidosiren collected by him in the Gran 

 Chaco of Paraguay during 1896-97. The adult males exhibited 

 the characteristically varying appearances of the hind limb in the 

 periods before, during, and after the breeding season. Mr. 

 Kerr also exhibited specimens of the young of Lepidosiren, 

 illustrating especially the external gills and sucker, the disap- 

 pearance of these organs, and the change in the colour of the 

 animal associated with the surrounding conditions of light or 

 darkness. A small collection of Teleostean fishes collected in 

 the same swamps in which Lepidosiren was found, and identified 

 by Mr. Boulenger, was also exhibited. ^The Secretary called 

 the attention of the meeting to the arrival in the Society's 

 Gardens of four living specimens of the Australian Lung-fish 

 [Ceratodus forsteri), deposited by Mr. D. O'Connor, who gave 

 an account of the mode in which he had obtained them and 

 brought them to England. — Mr. G. A. Boulenger^ F. R.S., 

 exhibited specimens of the remarkable fish Polyptertis lapradti, 

 from the Lower Congo. They were provided with highly- 

 developed external opercular gills, the presence of which, he 

 remarked, was not dependent on age, as had been heretofore 

 supposed, because they were retained for a long period, if not, 

 in some cases, throughout life. — Mr. R. E. Holding made some 

 remarks on some interesting animals he had observed during a 

 recent visit to the Zoological Gardens at Belle Vue, Manchester. 

 —Prof. Howes exhibited, on behalf of Mr. E. W. L. Holt, a 

 specimen of a new British fish (Argentina silus), obtained 

 eighty miles south-west of the Scilly Islands. — Mr. Abbott H. 

 Thayer, of New York, explained his method of demonstrating, 

 by actual experiments, the underlying principle of protective 

 coloration in animals, and invited the members present, and 

 their friends, to witness an exhibition of his demonstrations 

 which (as arranged with the Secretary) would take place in the 

 Society's Gardens next day. — Mr. G. A. Boulenger, F. R S., 

 read a memoir on the collection of fishes made by Mr. J. E. S. 

 Moore in Lake Tanganyika during his expedition in 1895-96. 

 Twenty-six new species were described, of which eight were 

 made the types of new genera. — Mr. R. I. Pocock read a paper 

 on the scorpions, spiders, and So/ifuga collected by Mr. C. S. 

 Betton in East Africa between Mombasa and Uganda. Of the 

 seven species of scorpions, six species of Solifiiga, and thirty 

 species of spiders represented in the collection, five of the 

 Solifugm and twelve of the spiders were described as new, one 

 species of the latter, viz. Eucratosceltts longiceps, being made 

 the type of a new genus. — A communication was read from 

 Mr. J. Stanley Gardiner containing an account of the fungoid 

 corals collected by him in the Central Pacific. Twenty-one 

 species were treated of, of which six were described as new. It 

 was proposed to absorb the genus Tichoseris into Pavonia, and 

 the genera Maeandroseris, Coscinaraea, and Plesioceris into the 

 genus Psammocora. — On behalf of Dr. A. Duges, Mr. G. A. 

 Boulenger communicated the description of a new genus 01 

 Ophidia, proposed to be called Geatractus, for the reception of 

 Geophis tecpanecus, recently characterised by M. Duges. — Dr. 

 G. H. Fowler presented three papers relating to the .surface 

 and mid water collections made by him on H.M.S. Research in 

 the Faeroe Channel in 1896 and 1897. The first of these, by 

 Mr. I. C. Thompson, dealt with the Copepoda ; the second, by 

 Mr. E. W. L. Holt, treated of the collection of fish-larvae, and 

 included an account of the larval ontogeny of Scopelus glacialis ; 

 and the third, by Dr. Fowler, contained a description of his 

 new midwater net, and a discussion on the general features ot 

 the midwater fauna. 



