New Spectrum discoveries, 129 



ARTICLE X. — The New Spectrum discoveries:^ 



We give in this number a series of illustrationsf of the spectra 

 of flames, in which salts of Potassium, Sodium, Lithium, Stron- 

 tium, Calcium, Barium, and Caesium are volatilized, with the 

 solar spectrum for the sake of comparison. 



Fig. 1 represents the solar spectrum, with the most remarkable 

 of Fraunhofer's lines indicated by transverse bars. 



Fig. 2 is the potassium spectrum, nearly continuous between 

 Fraunhofer's lines G and D, but showing beyond these limits, two 

 characteristic lines, one named Ka, correspondent to the dark line 

 A, at the red extremity of the solar spectrum, and one Ky8, near the 

 remote extremity of the spectrum, and coincident with another of 

 Fraunhofer's lines. A third line, less distinct, and therefore less 

 valuable for purposes of analysis, coincides with the solar line B. 



The sodium spectrum is seen in Fig. 3, and is eminently char- 

 acteristic. It is distinguished by a single brilliant yellow lineNa, 

 and coincident with the dark solar line D. 



Fig. 4 exhibits the peculiarities of the lithium spectrum. It 

 shows an intensely brilliant crimson line Li a, and one less dis- 

 tinct orange line Li ^. 



The strontium spectrum (Fig. 5), is move complex ; out of eight 

 remarkable lines, six red, one orange, and one blue, four may be 

 particularized, the orange line Sr a, the two red lines Sr /?, and 

 fcjr y, and the splendid biue line Sr S. 



The spectrum represented in Fig. 6 is that of calcium, present- 

 ing two characteristic lines, the bright green line Ca jS, and the 

 intense orange line Ca a. 



Of all these spectra, that of barium, represented in Fig. 7, is 

 the most complicated. Three green lines, Ba a, Ba /3, Ba y, are 

 most to be relied on for the determination of this spectrum. 



The new metal caesium, the spectrum of which is represented 

 by Figure 8, was discovered by Bunsen from the appearance of 

 the two blue lines Ca a and Ca (S, in the spectrum produced 

 when the residue from the evaporation of the mineral waters of 

 Baden and of Diirklieim was iguited. 



Buuseu afterwards announced the discovery of another of 

 new metal, which he names rubidium, and which he detected in 

 a similar manner in the residues of the same mineral waters, by 



* See page 224 of the last volume of Canadian Naturalist. 

 t Reduced from the London Review. 

 Can. Nat. 9 Vol. YII. 



