652 
ME. J. NORMAN LOCKYER ON SPECTRUM-ANALYSIS 
It will be seen from the above that my researches have convinced me that the opinion 
o 
held by the illustrious Angstrom, that metallic elements (in which I include hydrogen) 
have only one spectrum, is the only tenable one ; and it is to be hoped that science will 
soon be enriched by the results of more experiments similar to those recently made with 
such success by Mr. Schuster. 
Spectra of the Metalloids. 
Mitscherlich, in the paper to which I have so often referred, calls attention to the 
fact that the metalloids show the same spectra with regular shading as compound bodies ; 
but I think there is the difference to be remarked that, as a rule, the structure of the 
spectrum of the metalloids extends further along the spectrum from the least refrangible 
end than in the case of the spectra of compound bodies. As I do not think it is too 
much to say that, as a rule, the lines of the metallic elements are more prominent in the 
green and more refrangible parts of the spectrum than in the red (which may even be 
gathered from an inspection of the solar spectrum), the question arises whether it be a 
possibility that the molecules of a metalloid, in structure, lie between those of elements 
on the one hand and compounds on the other. 
Applications of these considerations to Solar and Stellar Spectra. 
Mitscherlich, in his first memoir, thus refers to the bearing of his observations with 
regard to the solar spectrum : — 
“ Ces essais montrent comment l’analyse spectrale peut conduireala connaissance des 
affinites mutuelles des corps simples a la temperature de l’atmosphere solaire. Si l’on 
observait, par exemple, le spectre d’un chlorure alcalin terreux dans la lumiere du 
soleil, on en pourrait conclure que son metal possede, a la temperature du soleil, une 
affinite pour le chlore plus grande que le potassium ou le sodium, ces derniers metaux 
existant a l’etat de liberte. Reciproquement, la connaissance des combinaisons existant 
dans l’atmosphere solaire pourra conduire a connaitre la temperature de cet astre, si 
toutefois nous ne parvenons jamais nous-memes a approcher de cette temperature. 
“ La presence du sodium libre dans 1’ atmosphere conduit a admettre qu’il n’y existe 
pas de corps electro-negatifs libres, tels que l’oxygene ou le soufre, et qu’ils n’y existent 
meme pas autrement en quantite assez abondante pour se combiner avec tout le sodium. 
coated surface was tlien introduced into the secondary current. The metallic lines appeared all along the 
spectrum, the “ structure ” (oxide spectrum) became fainter, and its intervals wider ; the bead soon became 
red-hot. A jar of 467 centims. gave lines only and no structure, and one of 2214 centims. the same result, the 
bead remaining cold. 
On usiug the bead as the electrode, the results were nearly the same ; but the heating-effect continued when 
somewhat larger jars were used than the one with 362 centims., which did not show this effect with the 
former arrangement. When the slit was very narrow it was observed that several of the bands of the oxide 
spectrum broke up into masses of fine lines, exactly liko those of the iodine vapour absorption-spectrum ; and 
this remarkable resemblance was rendered still more striking by the appearance of a beat like that shown by 
iodine. 
