ARC SPECTRUM OF IROX METEORITES. 
1025 
Substances certainly present. 
Substances probably pi’csent. 
Alanganese 
Strontium 
Cobalt 
Lead 
Nickel 
Litliium 
Chromium 
Molybdenum 
Titanium 
Vanadium 
Coj^per 
Didymium 
Barium 
Uranium 
Calcium 
Tungsten 
Sodium 
Yttrium 
Potassium 
Osmium 
Aluminium 
It is probable that the presence of the lines of copper in the arc spectrum of the 
meteorites is due to the fact that copper wire was used to bind the meteorites to the 
poles of the arc lamp. I have not yet had an opportunity of repeating the photo¬ 
graphs with specimens of the meteorites which have not come in contact with copper 
in this way, but observations of the spark and flame spectra of other portions of the 
same meteorite have not confirmed the presence of copper. 
4. Of the 43 lines in the tables for which no origins have been suggested, from the 
Kensington maps of metallic arc spectra, 29 are apparently coincident with lines 
mapped by Kayser and Runge in the iron spectrum, but which do not appear in the 
Kensington photographs. These are indicated in the tables by the letters K. and R. 
(Kayser and Runge), in the column for remarks. 
As I pointed out in my paper on the Iron Spectrum, these are very probably due to 
iron, as no other origins have been determined for them, their absence from the 
Kensington photographs depending upon the short exposure necessarily given, as 
ex^jlained in the paper. Accepting these as due to iron, there are only 14 lines for 
which no origins have been found. Their wave-lengths are 39G3'S, 3972‘2, 3992'0, 
3993-2, 4010-3, 4036-5, 4037-3, 4132-7, 4171-2, 4495-8, 4551-4, 5099-5, 5510-2, 
5669-2. The two lines at wave-lengths 3963-8 and 3972-2 are apparently coincident 
with lines in Mr. McClExIn’s photograph of the spectrum of iron, but are not 
recorded by any other observer. All these lines are very feeble, and it is therefore 
probable that they may ultimately be found to be faint lines in the spectra of some 
of the metallic elements, when photographs with longer exposures are available. 
5. Bearing in mind the lengths and intensities of the lines, the qualitative 
spectroscopic analysis of the meteorites can be carried a step further, and we can 
roughly approximate to tlie relative Cjuantities of the different substances present. 
Thus, it will be gathered by a reference to the tables, that tbe chief chemical difference 
between the two meteorites is that there is a preponderance of calcium in the Nejed 
meteorite, and of nickel, barium, and strontium in the Obernkirchen meteorite. 
The original negatives were taken by Sero;eant Kearney, R.E. ; the enlai-gements 
MDCCCXCTV.—A. 6 P 
