282 Address of Sir William Thompson. 
surrounding the sun and those stars in whose spectra it had 
(6) That other vapors than sodium are to be found in the 
atmospheres of sun and stars by searching for substances fii 
ducing in the spectra of artificial flames bright lines coinciding 
with other dark lines of the solar and stellar spectra than the 
Fraunhofer line D. 
The last of these propositions I felt to be confirmed (it was, 
perhaps, partly suggested) by a striking and beautiful ig 225 
ment, admirably adapted for lecture illustrations, due to Fou- 
cault, which had been shown to me by M. Duboscque Soleil 
and the Abbé Moigno, in Paris, in the month of October, 1850. 
A prism and lenses were arranged to throw upon a screen al 
a piece of brass, compounded of copper and zinc, was put into 
the cup, the spectrum showed all the bands, each precisely 2 
the place in ho it had been seen when one metal or the other 
had been used separately. 
It is much to be regretted that this great generalization was 
not published to the world twenty years ago. I say this, not » 
because it is to be regretted that Angstrém should have the 
‘hom of having, in 1858, published independently the statement 
a a5 . ¢ 
. 
n incandescent gas emits luminous rays of the same 
every kind of ray; or that Kirchhoff also should have, in 1859, 
might now be in possession of the inconceivable riches of ast? 
nomical results which we expect from the next ten years 2 
rred im. : 
Kire hoff belongs, I believe, solely the great credit of 
ving first actually sought for and found other metals than 
sodium in the sun y the method of spectrum analysis. 
publication of October, 1859, inaugurated the practice of soli! 
ce and stellar chemistry, and gave spectrum analysis an impus® od 
___ which in a great measure is due its splendidly successful cut 
“ 
Hse 
