110 



INDEX. 



Praseodymium chloride in 



mixtures of the alcohols and water . 95 



water Beer's law 94 



Praseodymium nitrate in water Beer's 



law 96 



Praseodymium, salts of 68 



Pulfrich, absorption spectra of chromi- 

 um compounds 63 



Rech, on the absorption spectra of aque- 

 ous solutions of neodymium chloride. 71 

 Recoura, absorption spectra of chromi- 

 um compounds 63 



Results obtained in this work 103 



Rontgen coil 9 



Russell, on the absorption spectra of 

 solutions of cobalt salts 11 



Sabatier, absorption spectra of chromi- 

 um compounds 63 



Schaeffer, Helen 98 



on the absorption spec- 

 tra of the rare earths. 70 

 Scheele, on the absorption spectra of 



praseodymium compounds 68 



Schottlander, on the absorption spectra 



of the rare earths 68 



Schunck, absorption spectra of chromi- 

 um compounds 63 



Settegast, absorption spectra of chro- 

 mium compounds 63 



Solutions, absorption spectra of 1 



Solvation 2 



and absorption 101 



Uhler and Jones 38 



Soret, absorption spectra of chromium 



compounds 63 



on the absorption spectrum of nickel 



chloride 39 



Sources of light 8 



Spectra, absorption, of solutions 1 



Spectrogram, making a 9 



Stiitzel and Muthmann, on the absorp- 

 tion spectra of salts of neodymium ... 70 



Summary and conclusions 100 



of results with cobalt salts. . . 35 



Talbot, absorption spectra of chromium 



salts 63 



Temperature, effect of on absorption. . . 101 



Theories of absorption 101 



Tichborne, on the color changes in co- 

 balt salts 11 



Uhler and Jones 



absorption .of cobalt chloride in 



methyl alcohol 17 



cadmium zinc spark 8 



Carnegie Publication No. 60 



Preface, 1 



on dehydration 37 



on solvation 38 



spectrograph 6 



work on cobalt salts ; 11 



Urbain, on the separation of the rare 

 earths 70 



Vernon, on the absorption spectra of 



chromium compounds 64 



Vierprdt, absorption spectra of chro- 

 mium compounds 63 



Vogel, absorption spectra of chromium 



compounds 63 



on the absorption spectrum of nickel 

 chloride 39 



Wain wright and Wratten 7 



Welsbach Light Co Preface, 71 



Wiedermann, E., absorption spectra of 



chromium compounds 63 



Wilson and Kriiss, on the absorption 



spectra of the rare earths 68 



Wratten and Wain wright 7 



Wyrouboff, on the color changes in 



cobalt salts 12 



Zimmermann, absorption spectra of 

 chromium compounds 63 



