December 30, 1922] 



NA TURE 



895 



a remarkable extent. The brown colour produced 

 by sulphuric acid with liver oils after oxidation, 

 behaves in exactly the same manner as the violet 

 colour with the fresh oils, being similarly increased 

 by the addition of natural oils. Oxidation of the 

 natural oils destroys this power, but it is unaffected 

 by hydrogenation. 



The Optical Society, December 14. — Sir F. W. 

 Dyson, president, in the chair. — T. Smith : A large 

 aperture aplanatic lens not corrected for colour. 

 A lens suitable for spectroscopic work with aplanatic 

 corrections for all zones mav have as large an aperture 

 as fji or still greater, all the surfaces being strictly 

 spheric? 1. An actual lens made bv Messrs. Ross, 

 Ltd., of 3 inches focal length and 3 inches aperture 

 possesses corrections comparable with those given 

 by the theoretical investigation. With a slightly 

 reduced aperture, correction for colour may be 

 obtained without prejudice to the quality of the 

 spherical corrections. The production of suitable 

 glass discs is the outstanding difficulty in the way 

 of great increases in the relative apertures of telescope 

 objectives. — T. Smith : The optical cosine law. 

 The law of refraction, the sine law relating to coma, 

 and other exact laws of optical instruments are 

 particular cases of a very general law which assumes 

 the form of a cosine relation. As an example of the 

 application of the law, the principles which should 

 govern the construction of a variable power telescope 

 yielding aplanatic correction at all magnifications 

 are investigated. — S. Weston : A constant bubble. 

 The alteration in the length of the air bubble in a 

 spirit level due to variation of temperature is avoided 

 in the new type of level produced by Messrs. E. R. 

 Watts and Son, Ltd., known as a " constant " 

 bubble. The first consideration is to obtain the 

 exact proportion of air and spirit. The cross section 

 of the tube containing the liquid is so shaped that 

 as the temperature is raised and the surface tension 

 gradually decreased, only the cross sectional area 

 of the bubble is affected, its length remaining un- 

 altered. 



Paris. 



Academy of Sciences, December 4. — M. Emile 

 Bertin in the chair. — M. Guillaume Bigourdan 

 was elected vice-president for the year 1923. — G. 

 Bigourdan : The Observatory of Paris, on the 

 200th anniversary of its construction. An historical 

 synopsis of the work done at the Observatory from 

 its completion in 1672 to 1699. — Maurice Hamy : 

 The measurement of small diameters by interference. 

 A development of Michelson's formula, without the 

 restriction a = o (a being the ratio of the width of the 

 slits to the distance between their centres). — A. de 

 Gramont : Quantitative researches on the line 

 spectrum of vanadium in fused salts. Two tables 

 are given showing the persistence of the chief vana- 

 dium lines by ocular and photographic observations. 

 In the visible spectrum the sensibility is 1 in 1000, 

 and this is increased by the use of photography to 

 1 in 100,000. The method can usefully be employed 

 in the examination of minerals. — Sir William H. 

 Bragg was elected correspondant for the section of 

 physics, in the place of the late M. Rene Benoit, 

 and J. B. Senderens correspondant for the section 

 of chemistry, in the place of the late M. Barbier. — 

 A. Schaumasse : Observations of the Skjellerup 

 comet (1922^) made with the equatorial of Nice 

 Observatory. Positions of the comet and comparison 

 stars are given for November 29 and 30. The comet 

 is of the nth magnitude. — J. Le Roux : The gravita- 

 tion of the systems. Reply to some criticisms by 



M. Brillouin. — J. Haag : The constancy of the 

 homogeneity of the fluid representative of the 

 different possible states of a gaseous mass. — Maurice 

 and Louis de Broglie : Remarks on corpuscular 

 spectra and the photo-electric effect. — Pierre Salet : 

 The law of dispersion of prismatic spectra in the 

 ultra-violet. In an earlier paper the author has 

 given a formula which represents exactly the observed 

 relation between the wave - length and the position 

 of a line in the spectrum, and this was verified for 

 wave-lengths between X3800 and 4900. Proof is 

 now given of the validity of the formula in the 

 ultra-violet to X2250. — F. Croze : The place of the 

 ultimate lines of the elements in the spectrum series 

 and their relations with the resonance lines. — Pierre 

 Steiner : The ultra-violet absorption spectra of the 

 alkaloids of the isoquinoline group. Papaverine 

 and its hydrochloride. The absorption curve of 

 papaverine is not that obtained by the addition of 

 the absorption curves of its constituents : the effect 

 of the isoquinoline nucleus preponderates. — Marcel 

 Sommelet : Tertiary amines derived from benz- 

 hydrylamine. — Raymond Delaby : The alkyl- 

 glvcerols. The conversion of the vinyl-alkyl-car- 

 binols into alkyl-glycerols. The ethylenic alcohol 

 is treated with bromine in acetic acid solution, these 

 converted into acetins by prolonged boiling with 

 sodium acetate, and the products separated by 

 fractional distillation. The acetins are hydrolysed 

 by a solution of hydrochloric acid in methyl alcohol. 

 — P. W. Stuart-Menteath : The San Narciso mine in 

 Guipuzcoa. — P. Viennot : The tectonic of the region 

 of Bagneres-de-Bigorre and of Lourdes. — Louis 

 Dangeard : Contribution to the geological study of 

 the bottom of the English Channel, based on recent 

 dredgings by the Pourquoi-Pas ? (August-September, 

 1922). The results are given on a chart, with special 

 reference to outcrops of the Lias and Eocene. — M. 

 Lecointre : The stratigraphy of the north of Chaouia 

 (Western Morocco). — J. Cluzet and A. Chevallier : 

 The radioactivity of the springs of Echaillon. The 

 deposits forming these springs are rich in radio- 

 thorium. This is the only spa in France admitting 

 the therapeutic utilisation of thorium emanation. — 

 G. Reboul : The determination, in cloudy weather, 

 of the vertical movements of the atmosphere : the 

 influence of clouds on the velocity of displacement 

 of depressions. — M. Bridel and G. Charoux : Cen- 

 taureidine, a product obtained from centaureine, a 

 glucoside from the roots of Centaurea Jacea. This 

 substance, which has the composition of C 8 H 16 8 , 

 is probably a derivative of flavone. — M. Aynaud : 

 Botrymycosis of sheep. 



Sydney. 



Royal Society of New South Wales, November 1. — 

 Mr. C. A. Sussmilch, president, in the chair. — R. S. 

 Hughesdon, H. G. Smith, and J. Read : The stereo- 

 isomeric forms of menthone. The ten stereoisomeric 

 forms of />-menthan-3-one stated to be theoretically 

 possible, and certain menthones and menthols 

 derived by reduction from the optically active and 

 inactive forms of piperitone are discussed. — E. Hurst, 

 H. G. Smith, and J. Read: A contribution to the 

 chemistry of the phellandrenes. Muta -rotation and 

 optical inversion on the part of /-a-phellandrene 

 a-nitrite occurs when it is dissolved in chloroform, 

 benzene, or acetone, and maintained at io° C. — H. G. 

 Smith : Notes on the chemistry of certain Australian 

 plant products. Pt. i. A resin coating the leaves and 

 stems of Acaciaverniciflua, the essential oil of the small 

 leaved Bceckia Gunniana, and the rubber and wax 

 from Savcostemma australe, are discussed. The milky 

 latex of Savcostemma australe contains about 7 per 



NO. 2774, VOL. I io] 



