458 



NATURE 



\ Aprils, 1875 



SOCIETIES AND ACADEMIES 



London 



Royal Society, March 18. — " On the Absorption-Spectra 

 of Metals volatilised by the Oxyhydrogen Flame," by J. Norman 

 I.ockyer, F.R.S., and W. Chandler Roberts, Chemist of the 

 Mint. 



The authors state that the researches which have recently been 

 published on the absorption-spectra of various metals, first by 

 Roscoe and Schuster, and subsequently by one of themselves,* 

 establish beyond all question the facts that — 



1. In addition to the well-known line-spectta, channelled- 

 space spectra are produced by the vapours of certain metals ; 

 and, 



2. Such spectra are produced by vapours which are com- 

 petent to give, at other times, not only line-spectra, but con- 

 tinuous spectra in the blue, or blue and red. 



As the temperature employed (or the volatisatiuu of the metals 

 in these experiments did not exceed bright redness, the range of 

 metals examined was necessarily limited. It was therefore con- 

 sidered desirable to extend these observations to the less fusible 

 metals, as well as to ascertain whether the spectra of those which 

 volatilised at the lower temperature would be modified by the 

 application of a greater degree of heat. For this purpose they 

 employed an oxyliydrogen blowpipe, and the lime still used by 

 Stas for the distillation of silver, his arrangement being modified 

 in order that the metallic vapour might be conducted into a lime 

 tube or tunnel heated to whiteness, so placed that a beam from 

 an electric lamp could readily traverse it. 



The apparatus employed consists of a block of lime traversed 

 by a tube 16 centims. long and 30 millims. diameter. A 

 receptacle, open at the upper surface of the lime-block, in order 

 to admit of the introduction of the oxyhydrogen blow-pipe, com- 

 municates with the centre of the tube. The ends of the tube or 

 tunnel in the lime were closed by glass plates held on by a 

 suitable clip. Small lateral orifices were cut in the lime for the 

 insertion of tobacco-pipe stems, through which a stream of 

 hydrogen could be passed into the tube and receptacle. 



An electric lamp was placed opposite one end of the tube and 

 a spectroscope opposite the other This last instrument was by 

 Desaga, of Heidelberg, and its single prism, the angle of which 

 was 60°, was capable of distinctly separating the D lines, at the 

 same time that it enabled us to see the whole spectrum in a 

 single field of view, an essential point in such inquiries. 



Some preUminary experiments indicated the advisability of 

 increasing the length of the column of vapour. To eflect this, a 

 tube 30 centims. long was made in a fresh block of lime, the 

 cavity being arranged as before ; in each end a short accurately 

 fitting iron tube, luted with a mixture of graphite and fire-clay, 

 was inserted ; and the total length of the column thus became 

 60 centims. 



The lime-block with its fittings was then placed in a charcoal 

 furnace, by means of which the whole could be raised to a high 

 temperature. As soon as the block was heated to biight red- 

 ness, the metal, the vapour of which was to be examined, was 

 introduced into the receptacle, and the flame of the oxyhydrogen 

 blowpipe was allowed to play on its upper surface, care being 

 taken to employ an excess of hydrogen. In almost every case 

 the metal experimented on was rapidly volatilised (the excep- 

 tions being gold and palladium). As the glass plates rapidly 

 became clouded by the condensation of the metallic vapours, it 

 was necessary to adopt an arrangement by which they could be 

 easily replaced. The authors assured themselves that oxides wetfe 

 not present to disturb the accuracy of the results. 



They ascertained that the effect of oxides, and of the metallic 

 rain due to condensation, was to produce a general absorption 

 obviously different from the special effects of absorption which 

 they record. Silver may be given as an example of the method. 

 Fifty grammes of pure metal were placed in the cavity, and 

 this amount produced a continuous supply of vapour for about 

 ten minutes. 



With the smaller thickness given by the first lime block, and 

 with a less powerful blast, the spectrum of silver consisted of an 

 absorption in the blue which at times extended almost to the 

 green. 



With the elongated tube and a stronger blast an exquisite 



channelled-space absorption was observed, the channels being 



far enough apart to render them very conspicuous in the field of 



view ; at the same time there was continuous absorption in the 



* Locliyer : Proc. Roy. Soc'.v. xxii. p. 371, 



blue. It was specially observed that there was no absorption in 

 the red. 



The results of experiments on the following metals and metal- ) 

 loids are then described : — Copper, sodium, calcium, aluminium, I 

 zinc, cadmium, manganese, iron, cobalt, nickel, chromium, tin, 

 antimony, bismuth, lead, thallium, gold, palladium, selenium, 

 and iodine. 



The authors conclude that these experiments, conducted at 

 the high temperature of the o.\yhydrogen flame, go far to sup- , 

 port the conclusions which were drawn from the experiments at i 

 a lower temperature. First, in passing from ihe liquid to the 

 most perfect gaseous state, vapours are composed of molecules 

 of different orders of complexity ; and second, this complexity 

 is diminished by the dissociating action of heat, each molecular 

 simplification being marked by a distinctive spectrum. There 

 is also an intimate connection between the facility with which the 

 final stage is reached, the group to which the element belongs, 

 and the place which it occupies in the solar atmosphere. 



" On Traumatic Inflammation of Connective Tissue," by G. 

 Thin, M. D. Communicated by Prof. Huxley, Sec. R.S. 



Linnean Society, April i. — Dr. G. J. Allman, F.R.S., 

 president, in the chair. — The President, on taking the chair, said : 

 " I cannot allow the business of the evening to commence with- 

 out one word expressive of the deep sorrow which we all feel in 

 the death of one of our most distinguished Fellows and ablest 

 officers. In our late treasurer we had a man of refined and cul- 

 tivated mind, of honest and straightforward purpose, and of a 

 simplicity and kindliness of character thit endeared him to all who 

 knew him. IMr. Hanbury has been taken away from us at a time of 

 life when we might still have looked forward to much and valuable 

 work, and it now only remains for us to accept in sorrow the 

 loss which deprives the Society of a conscientious and efficient 

 oflicer, and many of us of a valued friend." — The following 

 papers ^vc^e read : — Notes on Octopus vulgaris. Lam., by Mr. 

 W. S. Mitchell. — On the connection of vegetable organisms 

 with small-pox, by Dr. E. Klein, Assistant- Professor at the 

 Laboratory of the Brown Institution. A report of this paper 

 will shortly appear in the Proceedings of the Royal Society. 



Chemical Society, April i. — Prof. Abel, F.R.S. , in the 

 chair. — Reseorches on the action of the copper- zinc couple on 

 organic bodies (viii.) : on chloroform, bromoform, and iodoform, 

 by Dr. J. H. Gladstone and Mr. A. .Tribe, was read by the 

 latter. — Dr. W. A. Tiiden then read a paper on the action of 

 nilrosyl- chloride on organic bodies (ii.) : on turpentine oil. The 

 action gives rise to a molecular compound of terp ene and the 

 chloride, which, by the action of alcoholic potash, yields nitroso- 

 tapcnc, CioHjjNO. — Dr. A. W. Hofmann made two communi- 

 cations to the Society : one, on the decomposition of the fulmi- 

 nates by ammonia and by sulphuretted hydrogen ; the other, a 

 striking lecture experiment showing the atomic relations of oxygen 

 and chlorine. 



Royal Horticultural Society, March 17. — Scientific Com« 

 mittee. Mr. P. Edgeworth, F.L. S., in the chair. — Flowering 

 specimens of Bambusa gracilis, Hort., were sent from Trentham 

 Gardens by Mr. Stevens. — Mr. Grote, F.L.S., sent extracts from 

 the Proceedings of the Agri-Horticultural Society of India, relative 

 to the growth of fungi in the interior of ant-hills. According to Dr. 

 Cunningham the species was an Agaricus of the section Lepiota, 

 They arise from a peculiar substance found in the ant-hills, and 

 which probably consists of vegetable debris permeated by 

 mycelium. According to Belt, a similar substance is found in the 

 nests of the leaf-cutting ants of Nicaragua, and is supposed by 

 him to serve as food, the ants cutting and storing the leaves for 

 the sake of the fungi which are subsequently developed in the 

 debris. — Prof Thiselton Dyer exhibited, under the microscope, 

 examples of the ascospores of yeast. They were obtained by 

 cultivating yeast on moist slabs of plaster of Paris in a damp 

 atmosphere. After about ten days the cells of the yeast, which 

 had been starved by this treatment, developed from two to fon* 

 spores in their interior. These, when placed under appropriate 

 conditions, were found to be capable of germinating, and so of 

 reproducing actively growing yeast. De Seynes had observed 

 them in Myccdtrina vini in 1868, but they had been first described 

 by Max Reess in 1S70, in yeast. — Copies of the Meteorological 

 Society's report on the observations of phenological phenomena 

 were placed on the table. — Dr. Masters called attention to the 

 bea'.itiful specimen of the fruit of Ncdyc/iium Cardncriauum, 

 sent by Mr. Bennett from Hatfield. It had not hitherto been 

 known to fruit in cultivation. 



