466 Scientific Intelligence. 



sponding to an angle of " reflection " of 5° 6*5'. The wave-lengths 

 of the a, and fi x lines of iodine were found to be 0*437 X 10 -B cm. and 

 0*388 X lO - * cm. respectively. The corresponding data for tellu- 

 rium are given as 0*456 X 10 -8 cm. and 0*404 X 10"'" cm. Conse- 

 quently the succession of the elements should be tellurium-iodine, 

 as de Broglie found and as would be expected from the chemical 

 properties of these elements. When the atomic numbers for cad- 

 mium (48), indium (49), tin (50), antimony (51), tellurium (52), 

 iodine (53), and barium (56) are laid off as abscissas with the cor- 

 responding values of the square root of the reciprocal of the 

 wave-lengths as ordinates, the points obtained fall very nearly on 

 two parallel straight lines pertaining respectively to the a 1 and (3 1 

 lines of the radiators. The a 1 locus lies nearer to the axis of 

 atomic numbers than the /3 1 graph. The question, therefore, 

 seems to be settled in favor of the tellurium-iodine succession. — 

 Verh. d. deutsch. physih. Gesell.,~No. 1, p. 39, 1916. h. s. it. 



8. The Distribution of Intensity in Broadened Spectrum 

 Lines. — In a paper presented before the Royal Society of London 

 J. W. Nicholson and T. R. Merton made the following import- 

 ant statements. (1) Using a neutral-tinted wedge, the actual 

 distribution of intensity in broadened spectrum lines can be accu- 

 rately measured. (2) With this arrangement quantitative meas- 

 urements of the hydrogen line Ha have been made, and quantitative 

 observations of other lines of hydrogen, helium, and lithium. 



(3) The intensity-distribution of lines, broadened by condensed 

 discharges and at high pressures, does not follow the well-known 

 probability law known to obtain under certain specified conditions. 



(4) The broadening of Ha is symmetrical. (5) The most general 

 characteristic of all the curves obtained is that their curvature is 

 away from the axis perpendicular to the wave-length scale. (6) 

 The existence of more than one component accords with the view 

 that electrical resolution of lines is the origin of their broadening. 

 (7) On the supposition of several components symmetrically dis- 

 tributed about the centre, the only general law consistent with 

 the distribution of curvature is that of a sum of linear exponen- 

 tial terms, one for each component. (8) It is shown that in these 

 circumstances discontinuities in the slope of the curve must occur. 

 Those found in the curve for Ha are in quantitative accordance 

 with those expected from available data with respect to electrical 

 resolution. (9) Quantitative observations of Ho, H y , and the 

 diffuse series of helium and lithium confirm the view that electri- 

 cal resolution is the principal cause of the phenomena. — Nature, 

 vol. xcvii, p. 73, March 16, 1916. h. s. it. 



9. Magnetic Declination in the United States for January 1, 

 1915. — A new isogonic chart for this country, prepared by 

 Daniel L. Hazard, has recently been issued by the U. S. Coast 

 and Geodetic Survey. It is based upon a large number of obser- 

 vations, including those at more than 1000 new stations. The 

 lines of equal annual change are given as well as those of equal 

 declination. 



