42 2 



NATURE 



[November 24, 192 1 



stress. The blackboard model polygon, with the two 

 end sides lonj^, and four short sides, was rolled over 

 on a lath fixed to the board, while the apex drew five 

 circular arcs. The vertical ordi nates gave the square 

 roots of maximum bending moments on a 42-ft. girder 

 due to the transit of a 30-ft. 42-ton locomotive. The 

 short sides of the polygon doubled are the distances 

 apart of its five wheels, while the five spaces into 

 which the span is divided by perpendiculars from the 

 intersecting points of the arcs give, numerically, the 

 loads on the wheels. The cycloid is an extreme case, 

 and an interesting curve modified from it was shown, 

 and a new pair of conjugate load areas that balance 

 the linear circular rib and lead to a geometrical solu- 

 tion of the equilibrium of the semi-circular masonry 

 arch. 



P.\RIS. 



Academy of Sciences, November 7. — M. Georges 

 Lemoine in the chair. — C. RIchet : An optical illusion 

 in the appreciation of velocity. — G. Charpy and G. 

 Decorps : The determination of the degree of oxida- 

 tion of coal. An empirical method based on the 

 extraction of the constituents of the coal by 50 per 

 cent, soda solution at 100° C, and measurement by 

 permanganate of the amount of oxygen required for 

 the oxidation of the organic matter. — G. Jnlia : A 

 class of functional equations. ^ — H. Villat : Certain 

 integral equations p>ossessing an infinity of solutions 

 with an unlimited number of arbitrary parameters.- — 

 K. Popoff : The development of an arbitrarv function 

 in series according to a suite of given functions. — P. 

 Boutroux : The functions associated with an "auto- 

 genous " group of substitutions. — M. Riabouchinski : 

 The general equations of movement of solid bodies in 

 a perfect incompressible fluid. — M. Michkovitch : The 

 rectifications of the ephemerides of the minor planets. 

 - — M. Salet : Spectrophotometry of stars containing 

 carbon.^ — A. Buhl : The rble of analytical symmetries 

 in the relativist theories. — P. Langevin : The theory 

 of relativity and the experiment of M. Sagnac. A 

 proof that the generalised theory of relativity gives a 

 quantitative explanation of Sagnac's experiment.^ — M. 

 Decombe : The theory of the galvanic battery. — M. 

 Travers : A new method for the estimation of fluorine 

 at the ordinary temperature. Fluorine is obtained in 

 the state of soluble alkaline fluoride, potassium 

 silicate and a little hydrochloric acid added, and pre- 

 cipitated as potassium fluosilicate by potassium 

 chloride. The precipitate is estimated by titration. — 

 M. Grandmougin : The homonuclear dibromoanthra- 

 quinones. — E. Rothe : The use of radiogoniometrv in 

 the study of storms and of atmospheric "'parasite" 

 currents. It is possible to predict the weather from 

 the observation of the parasite currents. — J. Lacoste : 

 The relation existing between the directions of depres- 

 sions and the directions of the maxima of the atmo- 

 soheric parasites. — Mile. Yvonne Boisse and P. Marty : 

 The plurality of the eruptive apparatus of the Cantal 

 massif.— R. Soueges : The embryogenv of the Bora- 

 gaceae. The last stages of the development of the 

 embryo in Myosoi'xs hispida. — St. Jonesco : The forma- 

 tion of anthocyanine in the flowers of Cobaea 

 scatideiis at the expense of the pre-existing glucosides. 

 The experiments of E. Rose, which gave negative 

 results for glucosides in the non-coloured flowers are 

 shown to be incorrect. Glucosides are always present, 

 and the author holds that the colouring matters are 

 produced at the expense of these pre-existing gluco- 

 sides. — H. Colin : The graft of sunflower on the 

 Jerusalem artichoke. Studies on the transformations 

 of the carbohvdrates.— A. Kozlowski : The formation 

 of the red pigment of Beta vulgaris by oxidation of 

 the chromogens. The chromogens extracted from the 



NO. 2717, VOL. 108] 



maritime beet and the white sugar-beet were while 

 or light vellovv. On oxidation these gave a red pig- 

 ment spe'ctroscopically identical with colouring matter 

 from the red beet. The chromogens from the white 

 beets have some properties in common with the 

 saponins; they have a bitter taste, and produce froth 

 and decolorisation of red-blood corpuscles,— P. Dan- 

 geard, jun. : The formation of aleurone grains in the 

 albumen of the castor-oil plant. The observations 

 described and illustrated lead to the conclusion that 

 the formation of the aleurone grains is only a par- 

 ticular case of a more general phenomenon, the evolu- 

 tion of the vacuolar system.— E. Chatton : A new 

 kinetic mechanism : svndinian mitosis in the plas- 

 modial parasitic Peridinians.— M. Baudouin : A method 

 for the determination of the minerals constituting 

 prehistoric metallic axes : use of spectrum analysis. 

 The presence or absence of tin is readily determined by 

 the spark spectrum without mutilating the specimen. — 

 F. H. Ouix : The role of the otoliths in the spon- 

 taneous movements of animals during jumping and 

 falling.— P. Brodin and P. Huchet : A nev.' anti- 

 anaphylactising substance, formaldehyde-sodium hydro- 

 sulphite.— G. Truffaut and M. Bezssonnof : The varia- 

 tions of. energv of Clostridium Pastorianum as 

 nitrogen-fixing organisms. The partial sterilisation 

 of the soil bv calcium sulphide increases, not only the 

 number of C. Pastorianum, but also their capacity 

 for fixing nitrogen.— C. Levaditi and S. Nicolau : 

 Neurotropic aftinity and the purification of the virus 



of vaccine. 



Cape Town. 



Royal Society of South Africa, September 28.— Dr. | 

 J. D. F. Gilchrist, president, in the chair.— J. Moir : 

 Colour and chemical constitution, pt. 15. A sys- 

 tematic studv of fluorescein and resorcm-benzme. 

 Colour-factors have been obtained by experiment 

 wherebv the colour of anv halogenated fluorescein can 

 be calculated. A preliminary investigation of/f^O''C>n- 

 benzine derivatives follows.-J. D. F. Gilchrist : The 

 origin of paired fins in fishes. 



Books Received. 



\ustralasian Antarctic Expedition, 191 1-14. Under 

 the Leadership of Sir D. Mawson. Scientific Reports. 

 Series C: Zoologv and Botany. ^ o' „ '^' P^""^/ " 

 Echinodermata Asteroidea. By Prof. R. Koehler 

 Pp. 308 + 75 plates (Sydney: Government Printing 



Office.) sS^. ^ .. r^ :n 



Stanford's New Map of the Pacific Ocean 30 in 

 X22^ in. (London: E. Stanford, Ltd.) Coloured 



sheet, AS. n ta u' rr 



The ^Larketing of Whole Milk. By Dr. H. E 



Erdman. (The Citizen's Librarv : Marketing series.) 



Pp xvi + 3^,3. (New York: The Macmillan Co.; 



London : Macmillan and Co., Ltd.) 215. net. 



The Wisdom of the Beasts. By • C. A Strong. 



Pp. x + 76. (London: Constable and Co., Ltd.) j^- 



Wisconsin Geological and Natural History Sur\ev 

 Bulletin No. 55 : Soil series, No. 27. Soil Survey of 

 Northern Wisconsin. Bv A. R. Whitson and others. 

 Pp iv + 46. Bulletin No. 58: Educational series. .No. 

 6 The Geographv and Economic Development ot 

 South-eastern Wisconsin. Bv Prof. R. H. Whitbeck. 

 Pp. x+2:;2. (Madison, Wis.) , • , 



Air Ministry : Meteorological Office. Geophysical 

 Memoirs, No." 17 : Simultaneous Values of Magnetic 

 Declination at Different British Stations. Bv Dr. U. 

 Chree. Pp. 175-200. 2... net. Geophysical Memoirs 

 No. 18 : Observations of Radiation from the Skv. ana 



