On the Chemical Analysis of the Solar Atmosphere. 185 
—13.34.42.21, that is —| 1243 | —]1342 |, and so for the 
other similar terms, and we have 
41234) = (12 .34413.42-4+14.23)?,) 
And so in general, n being any even number, the skew symme- 
trical determinant $123... is equal to the square of the 
Pfaffian 12..., where the law of these Pfaffian functions is 
12384 =12.84 418.42 414.28 
123456 = 12.3456 + 13.4562 + 14,5623 + 15.6284 + 16.2345 
where, in the second equation, 3456, &c. are Pfaflians, viz. 
3456 =34.564385.644+86.45; and so on. 
2 Stone Buildings, W.C., 
December 28, 1860. 
XXVIII. Letter from Prof. Kirncunorr on the Chemical Analysis 
of the Solar Atmosphere. 
To the Editors of the Philosophical Magazine and Journal. 
GENTLEMEN, Owens College, Manchester, 
February 1, 1860. 
{ RECEIVED a short time ago from Heidelberg the enclosed 
portion of a letter from Prof. Kirchhoff to Prof. Erdmann. 
As it gives a later account of Kirchhoff and Bunsen’s most im- 
portant researches than has yet appeared in the Nnglish journals, 
I think it may be of interest to your readers. 
I am, yours sincerely, 
Henry HE. Roscoz. 
“Since I sent in my last report to the Berlin Academy, I 
have been almost uninterruptedly engaged in following out the 
investigation in the direction I there indicated. I will not now 
speak either of the theoretical proof I have given* of the facts I 
there announced, or of the experiments by help of which Bunsen 
and I+ have shown that the bright bands in the spectrum of a 
flame serve as the surest indications of the metals present therein ; 
I will take the liberty, in this communication, of informing you 
of the progress I have made in the chemical analysis of the solar 
atmosphere. 
“The sun possesses an incandescent, gaseous atmosphere, 
which surrounds a solid nucleus having a still higher tempera- 
ture. If we could see the spectrum of the solar atmosphere, we 
should see in it the bright bands characteristic of the metals 
* Phil, Mag. July 1860. t+ Ibid. August 1860. 
