Frequencies in the Spectra of Various Elements. 4G9 



called by Hemsalech * to the fact that Charles de Wattevillef 

 in his exhaustive paper on Flame Spectra has recorded that 

 the wave-length A, = 3075'99 A.U. was the only radiation 

 belonging to the zinc spectrum which was emitted by the 

 flame of a burner supplied with the spray from a solution of 

 zinc chloride. Tn view of these results, it was thought that 

 the line \= 3075*99 A.U. should have come out on the plates 

 of McLennan and Thomson when the Bansen flame was fed 

 with the vapour from heated metallic zinc. 



The experiments with zinc were therefore repeated by us, 

 with the result that the line was identified among those con- 

 stituting the water-vapour group referred to by Ramage. 



In these experiments the particular type of Bunsen burner, 

 fig. V., used by McLennan and Thomson was adopted. To 



FIG. V. 



the top of any ordinary Bunsen burner Q a brass cylinder KL, 

 3'8 cm. in diameter and 8 cm. high, was soldered. The top 

 was closed by a lid containing an aperture about 2 cm. in 



* Hemsalech, Phil. Mag. vol. xxxiv. p. 221 (1917). 



t Be Watteville, Phil. Trans. Roy. Soc. ser. A, vol. cciv. pp. 139-163 



