Spectra Of Phosphorus Research Articles

The Spectra of Two and Three-Valence-Electron Atoms, Si II, P III, S IV, Si III, P IV and S V

New measurements of the vacuum spark spectra of silicon, phosphorus and sulphur have been made with a vacuum spectrograph. With the aid of these data it has been possible to analyse a large number of hitherto unclassified lines. In Si III and P IV the stronger singlet lines have been classified, while in these ions and in S V a large number of lines involving terms in which both electrons are excited have been identified. In Si II, P III and S IV many of the important quartet lines have been located.

A New Band System Probably due to a Molecule CP

WHEN investigating the band spectra of phosphorus I tried a discharge in a mixture of argon and phosphorus vapour. This discharge, with suitable arrangements of the concentrations of the two gases, shows an intense and extended band system in the wave-length region λ4000-λ2900 A. which does not occur in pure phosphorus vapour. So far as I am aware it has not hitherto been recorded. At the same time the Swan bands of the C2 molecule are very intense in the visible region, obviously due to tap grease and sealing wax. As in a mixture of argon and a small trace of nitrogen, under the same conditions of discharge, the CN bands are specially strong (the C2 bands of course also being present), it seems very probable that the new band system is due to a molecule CP which would be the analogue of CN. So far as I know, such a molecule, or a molecule (GP)2 which would be analogous to (CN)2, has not been found chemically. If the above conclusion that the new band system is due to CP is correct, it might be possible also to get chemical evidence of some simple CP compound. In order to obtain a further test of the above conclusion, an attempt is being made to get exposures strong enough to show the bands due to the isotope molecule C13P which would make possible a definite identification of the emitter of the bands in question.

The Arc Spectrum of Phosphorus

THE arc spectrum of phosphorus has been investigated by Saltmarsh and by McLennan in the Schumann region, and the lines belonging to the fundamental transition 2M2(M2N1) have been arranged according to Hund's theory by McLennan (Trans. Roy. Soc. of Canada, vol. 21, sec. 3; 1927).

The spectra of doubly- and trebly-ionised phosphorus (P III and P IV)

Previous to the classification of some of the lines of the phosphorus spectrum into series of the doubly-ionised atom, which is described in the present paper, no series had been observed for the elements of group V of the periodic table. The element phosphorus of this group was selected for investigation because the spectrum corresponding to each stage of ionisation was expected to bear a marked resemblance to that of the silicon atom of one lower stage of ionisation, of the aluminium atom of two stages lower, of the magnesium atom of three stages lower, and so on. The series corresponding to successive stages of ionisation of some of these atoms had already been worked out, and hence, if the series spectra of phosphorus could be observed, a direct comparison would be possible. The spectrum of the neutral atom of phosphorus has been identified and described by the present writer, but no series relationships have been found. This is probably due to the limited range of the spectrum which it has been possible to investigate so far. The region investigated by Geuter in 1907 extends from λ 5727·90 to λ 2389·93 and contains 530 lines which are ascribed to phosphorus. Kayser gives also the approximate wave-lengths of a few more lines at the red end up to λ 6505. Only four of these lines belong to the arc spectrum, and the rest are therefore lines of phosphorus at one or more stages of ionisation.

Societies and Academies

PARIS. Academy of Sciences, October 4.—M. Henri Deslandres in the chair.—E. Picard: The International Congress of Mathematics at Strasbourg.—The President announced the death of Sir Norman Lockyer, and described the main lines of the scientific work carried out by this distinguished astronomer and correspondant of the Academy.—A. Lacroix: A series of alkaline syenitic potassic rocks in sodium minerals from Madagascar.—G. Bigourdan: Corrections of the normal time-signals sent out by the Bureau international de l'Heure from January 1 to March 19, 1920. Two types of signal are sent out: ordinary signals for the purpose of navigation, railways, etc., and scientific or rhythmic signals for use in observatories. The corrections for the directing clock are tabulated; those for the time-signals will be given later.—C. Sauvageau: The membranes of some algae (Florideæ) and the setting of the gelosic hydrosol.—M. Gevrey: The determination of Green's functions.—T. Varopoulos: Some theorems of M. Rémoundos.—J. Soula: Generalisation of a theorem of M. Leau relating to the determination of the singular points of a function defined by a Taylor's series.—A. Bilimovitch: The intrinsic equations of motion of a solid body.—V. Vâlcovici: The hydrodynamical forces in movements differing between themselves by a uniform rotation of space.—J. Andrade: The problem of the spiral cylinder. —A. Vela: Observations of Nova Cygni. An account of work done on the new star at the Madrid Observatory. Maximum brightness, about 1.4 magnitude, was attained on August 24. A number of spectroscopic observations were made.—J. Bergengren: The absorption spectrum of phosphorus for the X-rays, The substances employed included ammonium phosphate, Bridgemann's black phosphorus, phosphoric acid, and commercial red phosphorus. It was found that the wave-lengths of the limits of absorption were different for the various kinds of phosphorus. This is the first time that the chemical state of an element has been found to have an influence on its X-ray spectrum.—M. de Broglie and A. Dauvillier: The fine structure of the absorption discontinuities in X-ray spectra. A discussion of some phenomena having a bearing on the results described in the preceding paper by M. Bergengren.—A. Dauvillier: The mechanism of the chemical reactions caused by the X-rays. The only mineral substances sensible to the action of the X-rays are crystals for which I. Langmuir, Born arid Landé, and Debye and Sherrer have supposed and proved the existence of an ionic structure. All other sensitive substances, colloids, electrolytes, glass, etc., also contain ions. The cause of the chemical actions would thus be due to the destruction of the negative ions, which would lose their electrons under the impact of the rapid electrons constituting the corpuscular radiation. The violet coloration of alkaline glasses, the photo-electric properties of crystals, and the colour-changes in platinocyanide screens are considered from this point of view.—H. Copaux and C. Philips: The heat of oxidation of beryllium. Direct combustion of the metal in compressed oxygen in the calorimetric bomb gave unsatisfactory results; the combustion of the metal was never complete. The figure required was hence derived indirectly by measuring the heats of solution of the metal and its oxide in dilute hydrofluoric acid. The heat of oxidation, 151.5 calories, was high, and ranges beryllium with calcium (160 calories), lanthanum, (148 calories), and magnesium (144 calories).—G. Denigès: The microchemical reactions of radium: its differentiation from barium by iodic acid. The usual reagents employed in the microchemical reactions of barium, hydrofluosilicic, oxalic, and tartane acids, tartar emetic, potassium ferrocyanide, and tartrate give identical results with barium and radium salts. Ammonium cyanurate, ammonium phosphomolybdate in ammonia solution, and potassium bromate, which are also good reagents for barium, give similar crystals, with radium compounds. Iodic acid, on the other hand, shows clear differences between the two metals, and reproductions of two microscope-slides are given to prove this. As showing the delicacy of the microchemical method, it is mentioned that afl experiments on the reactions of radium were carried out with 0.2 milligram of metallic radium added as the bromide.—R. Fosse: The qualitative analysis of cyanic acid.—A. Lumière and F. Perrin: A new class of hypnotics: the dialkylhomophthalimides. Starting with naphthalene, this is oxidised to phthalonic acid, which reduced bv hvdriodic acid leads to homophthalic acid, (CO.OH).C6H1. CH2CO.OH, the ammonium salt of which, evaporated to dryness and gently fused,gives the homophthalimide. From this dialkvl derivatives are readily obtained. Used as hypnotics, they possess the advantages of verv slight toxic power, and are practirallv free from unfavourable serondarv reation.—F. Kerforne: The tectonic of the Armorican massif.

On the spectra of phosphorus and sulphur

On the spectra of phosphorus and sulphur