184 THE CHEMISTKY OF THE SUN. [CHAP. 



Nor was this all ; some of the bright lines in the spectrum 

 of the photosphere itself were continued into the prominence 

 spectrum. Strange and unexpected as these observations were, 

 they were soon endorsed. Thus Vogel gave the following list. 1 



"Wave-length. 



u 6561-8 Hydrogen. 



D 3 5874-3 



DJ 5895-0 Sodium. ; 



ix, 5889-0 



5315-5 Iron(l) 



&! 5183-0 Magnesium. 



*a 5172-0 



b 3 5168-0 Nickel. 



# 4 5167'0 Magnesium. 



5017-6 Iron. 



4923-1 

 F 4860-6 Hydrogen. 



4340-0 



About the same time Lorenzoni directed his attention to this 

 subject, and not only indicated several new lines,^but gave 

 frequencies of appearance. His new lines, like some of the old 

 ones, had no counterparts among the Fraunhofer lines ; notably 

 one, which he indicated by /, at wave-length 4471 '2, and 

 another between B and c. 



In twenty-six protuberances seen in one month we have/ 

 appearing 19 times against hydrogen 26 ; and the unknown 

 substance which produces D 3 26 times against magnesium 8 

 and sodium 6. Three other lines, one between B and c, and 

 two between F and 5, were only seen once. 



Fortunately, Lorenzoni was not the only one who was 

 utilising the clear sky of Italy for this work. 



Tacchini saw a great number of lines brightened in his 

 observations of prominences extending from 1871 to 1873. 



1 H. C. Vogel, Beobachtungen, 1872, pp. 36, 37. 



2 Mcmoire della Societa degli spettroscopisti Italiani, vol. i. 1872. 



