February 20, 1896] 



NATURE 



383 



in a plane perpendicular to the axis of the instrument by means 

 of a micrometer screw. This form of spectroscope was found 

 to be of great utility in verifying the position of lines in the 

 spectrum. 



Geological Society, London, February 5.— Dr. Henry 

 Woodward, F.R.S., President in the chair.— On the Morte 

 Slates and Associated Beds in North Devon and West Somerset. 

 -Part I , by Dr. Henry Hicks, F.R. S. In a paper read before the 

 Society in 1890 the author stated that he had found the Morte 

 Slates to be fossiliferous, and had come to the conclusion that 

 they were the oldest rocks in the North Devon area and had 

 been thrust over much newer rocks, producing a deceptive 

 appearance of conformity ; and that there was not a continuous 

 upward succession in the rocks from the Bristol Channel to the 

 neighbourhood of Barnstaple. Since that paper was read, the 

 author has obtained much additional evidence bearing on the 

 succession, which was described so far as the position and age of 

 the Morte Slates in the Ilfracombe areaare concerned. — Evidences 

 of glacial action in Australia in Permo- Carboniferous Time, by 

 Prof T. W. Edgeworth David. The author, after summarising 

 the work of previous observers, gave an account of recent 

 observations made by himself In Hallett's Cove, near Ade- 

 laide, the pre-Cambrian rocks were strongly glaciated, strioe 

 being seen when the overlying glacial beds are removed, as 

 sharply cut as though caused by recent glacial action, and 

 trending nearly north and south, the ice having come from the 

 south. The overlying glacial beds were in places fairly strati- 

 fied, while parts contain abundance of well-striated boulders ; 

 these beds are from 23 to over 100 feet thick. Proofs were 

 obtained that in this case the glaciation occurred in an age inter- 

 mediate between Miocene and pre-Cambrian, and probably did 

 not antedate the close of the Palaeozoic period. In Wild Duck 

 Creek, near Heathcote, Lower Silurian (Ordovician) beds 

 exhibited strongly-grooved, polished surfaces, the grooves being 

 from S. 5" E. to N. 5° W. , the ice having probably come from 

 the south. They were succeeded by Permo-Carboniferous 

 glacial beds, consisting chiefly of mudstones with well-glaciated 

 boulders. At Bacchus Marsh Ordovician beds were also well- 

 striated and polished, and more or less nwtitoiines. There also 

 the ice came from a southerly point. These beds were suc- 

 ceeded by Permo-Carboniferous glacial beds having an approxi- 

 mate thickness of at least 2000 feet, consisting of mudstones 

 with well-glaciated boulders. It was extremely probable that 

 the glacial beds of Bacchus Marsh, Wild Duck Creek, and 

 Springhurst in Victoria were of homotaxial if not contem- 

 ])oraneous origin, and they may probably be correlated with the 

 glacial conglomerates at Mount Reid in Tasmania, these corre- 

 lations being mainly based on lithological evidence. 



Cambridge. 

 Philosophical Society, January 27. — Prof. Liveing, Vice- 

 President, in the chair. — On longitudinal vibrations in connec- 

 tion with recent photographic discoveries, by Prof J. J. Thom- 

 son (see p. 379). — On the equilibrium of isotropic elastic solid 

 shells of nearly spherical form, by Dr. Chree. Attention was 

 chiefly devoted to the case of a thin shell exposed to 

 uniform, but different, normal pressures over its two surfaces. 

 The effect of external pressure, it was proved, is to increase, 

 while that of internal pressure is to diminish the original 

 departure from sphericity. — A harmonic analysis of the amount 

 of solar radiation received at the different latitudes on the 

 earth's surface, by Mr. R. Hargreaves. The amount of solar 

 radiation falling on the earth's surface in any latitude is expressed 

 by a harmonic series containing constant, annual, semi-annual 

 terms, and so forth. The dependence of the coefficients on 

 latitude, and also on the astronomical elements obliquity of the 

 ecliptic, eccentricity, and longitude of perihelion, was fully dis- 

 cussed. Numerical results were given in connection with each 

 point, showing the extent to which the present values may be 

 modified by such secular changes as are known to astronomers ; 

 and complete numerical data are thus provided for the discussion 

 of the question whether these astronomical changes are a z-^ra 

 I ansa in the explanation of changes of climate. 



Edinburgh. 

 Royal Society, January 20— Rev. Prof Flint in the chair.— 

 Dr. Buchan read a paj^er on the recent great atmospheric pressure. 

 So far, the highest reading had been that recorded at Ochlertyre, 

 in Perthshire, where 31 '107 inches was registered on the 9th. 

 This place, curiously enough, had the "record" for low read- 



NO. 1373, VOL. 53] 



ings, a pressure of 27*333 inches having been recorded there 

 in January 1884. This was the lowest ever recorded anywhere. 

 — Prof. Crum Brown showed and discussed an experiment 

 illustrating the modern theory of salt solutions.— Dr. A. Lock- 

 hart Gillespie gave statistics from the Infirmary records of the 

 past fifty years, illustrating the relations of weather, influenza, 

 and disease. Diseases of the respiratory system were more 

 common during cyclonic weather, and cardiac troubles showed 

 a marked increase after epidemics of influenza. The idea that 

 influenza was more severe than it used to be was not borne out 

 by facts. — Dr. John Murray and Mr. Robert Irvine contributed 

 a paper, replying to criticism, on the chemical changes in 

 marine deposits. — Prof Tait illustrated the looped, concave- 

 upward path of a rotating spherical projectile by means of a 

 spherical india-rubber balloon. 



January 27. — Prof. McKendrick in the chair. — By request 

 of the Council, Mr. Frederick Ives, of Philadelphia, gave an 

 address on the stereo-photochromoscope. The essential features 

 of Mr. Ives' method are as follows. By means of a specially 

 constructed stereoscopic camera, three pairs of negatives are 

 taken at once. Each pair, by a suitable intervention of colour- 

 filters, secures those parts of the object from which one of the 

 Young- Helmholtz three primary colours is reflected. When the 

 six positives are subjected to the synthetic action of the photo- 

 chromoscope, a coloured, solid-looking, optical illusion is the 

 result. Not the least interesting feature of the process, as was 

 remarked at the meeting, is the light which it throws on the 

 Young- Helmholtz theory of colour vision. 



February 3 — Prof. Chrystal in the chair. — Prof Tait read an 

 obituary notice of Prof Blackie by the Rev. Dr. Walter Smith. — 

 Dr. W. W. J. Nicoll described experiments he had carried out on 

 the behaviour of the iodine molecule in solution. His method was 

 different from any yet tried, viz. the determination of the mole- 

 cular volume of the iodine in different solutions, and his results 

 agreed well with those of others approaching the problem from 

 different sides. He found that the value of the iodine molecule 

 in solution was about 85, and this whether it was of the form 

 I2 or I4. His conclusion was that the molecules, in the gaseous 

 form, and in dilute solution, were truly comparable. — In Dr. 

 E. H. Barton's absence. Prof Tait read a paper on the tem- 

 perature-variation of the magnetic permeability of magnetite. 

 His results, as exhibited graphically, showed that the perme- 

 ability reached its maximum about 300°, suffered a very sudden 

 decrease about 500°, and remained constant afterwards. — Prof 

 Tait gave a note on centrobaric shells. Thomson and Tait 

 prove the proposition that a shell, whose density is inversely 

 as the cube of the distance from an internal point, has a true 

 centre of gravity, by considering the forces of attraction. Prof 

 Tait gave a demonstration of a very much simpler and shorter 

 proof, which had since occurred to him, from the point of view 

 of potential. 



Paris. 

 Academy of Sciences, February 10. — A study of uranium 

 carbide, by M. H. Moissan. — Action of high frequency 

 currents upon bacterial toxines, Ijy MM. d'Arsonval and 

 Charrin. In these experiments especial care was taken to 

 eliminate, as far as possible, all electrolytic action of a 

 chemical nature. Two different cultures were used (pyo- 

 cyanic and diphtheric toxines), and in both cases these were 

 found to have their virulence diminished after passage of the 

 high frequency current. It was also noticed that this attenuated 

 virus more or less protected the animals against further injec- 

 tions of the original virus.— On the application of the Rontgen 

 rays to surgical diagnosis, by MM. Lannelongue and Oudin. 

 An application to some diseases of the knee and thigh. The con- 

 clusion is drawn that although the application of the new light to 

 surgery has not led to the discovery of any points previously 

 unnoticed, yet it has in all the experiments given results in agree- 

 ment with the clinical diagnosis. — Microbial associations and 

 tuberculous suppurations, by MM. Lannelongue and Achard. 

 A discussion of the conditions under which other microbes are 

 associated with the tubercle bacillus. — On the structure of Mount 

 Joly, near Saint-Gervais, by MM. Marcel Bertrand and E. 

 Ritter. The view previously held about this mountain, that it 

 had escaped the violent actions to which the neighbouring rocks 

 had been subjected, and that foldings had not taken place, is 

 shown to be untenable. This spot is, in fact, the region where 

 the displacements of the strata have been pushed to the greatest 

 extent. — On campholide, the reduction product from camphoric 

 anhydride, by M. A. Haller. Camphoric anhydride reduced 



