118 The Ohio Journal of Science [Vol. XVI, No. 4, 



Manganous Chloride. 



Low heat gave a continuous region from 5900 to 4450, 

 diffuse at both ends. 



The prominent Hnes were identified as manganese 6017, 

 4822, 4783 and 4754, in addition to three or four hnes belonging 

 to hydrogen and mercury. The spectral examination showed 

 the presence of the base of the compoimd only; no lines due 

 to chlorine were detected. 



III. Bromides. 



Calcium Bromide. 



Low heat gave a continuous region, 5500 to 4850, shading 

 off at each end. 



After the discharge had passed for a little time, but before 

 heating the apparatus, the lines present were measured and 

 identified as those of hydrogen and mercury. This indicates 

 that practically none, if any, of the calcium bromide vaporized 

 and dissociated under low pressure at room temperature. 



Mercurous Bromide. 

 Strong heating gave a continuous region from 5072 to 4912. 



Zinc Bromide. 



With excessive heating there was obtained a continuous 

 region from 5550 to 5055, neither limit being sharply defined. 

 With the bottom of the lower electrode red hot there was a 

 small, but very intense continuous band, about 100 Angstroms 

 wide, with its center at about 5055, together with a region, 

 much less luminous, which appeared to be continuous from 

 5550 to 5150. 



ABSORPTION SPECTRA OF THE VAPORS. 



Chapman (Phys. Rev. 2nd Series, Vol. IV, p. 28, 1914) 

 came to the conclusion that the vibrating system giving the 

 emission spectra of the compounds was also potent in producing 

 absorption in solutions. It is reasonable to suppose that the 

 vibrating system might also persist and preserve its identity 

 in the vaporous state and that the absorption spectrum of the 

 compound should be the complement of the emission spectrum. 

 Several attempts were made to see if such were the case. A 

 tube was constructed, 22 inches in length, with an inside 

 diameter of 1}/^ inches. The ends were provided with jackets 

 for water cooling. Plano-convex lenses of about 20 cms. 



