T H E 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[SIXTH SERIES ] 



JANUAR Y 1917 



I. On the Relative Behaviour of the Light Radiations emitted 

 by Iron Vapour under the Influence of Thermal and 

 Chemical Actions in Flames. By G. A. Hemsalech, 

 Honorary Research Fellow in the University of Man- 

 chester *. 



[Plate I.] 



1. Introduction. 



IN his well-known researches on air-coal gas flame spectra 

 Dr. de Watteviile has shown that by far the greater 

 number o£ lines are emitted by the region of the inner blue 

 cone and only relatively few are observed in the outer 

 mantle f • 



A few years later Dr. de Watteviile and the present author 

 established a convenient and at the same time very simple 

 method of obtaining the spectra of flames, and were thereby 

 enabled to extend the research to the spectra emitted by 

 various high-temperature sources J. Since the method and 

 the principal results to which it has led have not been 

 accurately recorded in modern text-books on spectroscopy, it 

 may be useful to state them briefly. 



Our method consists in feeding the flame with the finely 

 divided material supplied by powerful condenser discharges. 

 The electrodes, made of the metal the spectrum of which it 



* Communicated bv Sir E. Rutherford, F.R.S. 



t C. de Watteviile/ Theses de Doctored, Paris 1904; also Philos. Trans. 

 Roy. Soc. Series A. vol. cciv. pp. 139-168. 



X Hemsalech ai d de Waiteville, Comptes Rendus de VAcademie des 

 Sciences, vol. cxliv. p. 1338 (1907). . 



Phil. Mag. S. 6. Vol. 33. No. 193. Jan. 1917. B 



