260 
ME. J. NOEMAN LOCKYEE ON SPECTEUM ANALYSIS 
COme 6154-2} in the red and 5681 * 4 } in the y ellow > the latter P air having a slight 
5154-8) 
advantage over the former. 5150.5 f come next, and the shortest is 4982-5, really a 
double line, but so nebulous and ill-defined that Thalen has represented it as single. 
5895 - 0 ) 
In the chloride we find D ^g^g.Q>all across the spectrum, and all the others have 
vanished but a trace of f 
5581-4 
Magnesic Chloride, Mg Cl 2 . — Magnesium has three lines ( b ) surpassing all the others 
in length; their wave-lengths are 5183-0, 5172-0, and 5166-7 : these lines alone are con- 
stant in the chloride ; 4481-0, the winged line, sometimes flashes in. 
Zincic Chloride, Zn Cl 2 . — Zinc has three long lines in the blue, 4809-7, 4721-4, 
4679-5 ; these only are visible in the spectrum of the chloride. One line, 6362-5, in the 
extreme orange, is of the same length, apparently, as the shortest of the three blue lines, 
but is not visible, possibly on account of its faintness. 
Strontic Chloride, Sr Cl 2 . — Strontium has one extremely long line, 4607-5, and this 
with two in the indigo, 4226-3 and 4215-3, next in length to it, are alone seen in the 
chloride spectrum. 
Cadmic Chloride, Cd Cl 2 . — Cadmium, like zinc, has three lines of greater length than 
all the rest — one in the blue-green, 5085-0, and two, 4799-0 and 4676'8, in the blue. 
These alone appear in the spectrum of the chloride. 
Plumbic Chloride, Pb Cl 2 . — Lead has its longest line, 4058-0, in the violet ; this line 
alone is visible in the chloride spectrum; 5607-0 in the yellow-green, which appears 
nearly as long, is not visible. 
Baric Chloride, Ba Cl 2 . — Barium has three lines, distinguished by their great length . 
they are 5534-5 in the yellow-green, 4933-4 in the green, and 4553-4 in the indigo. 
These only are visible in the chloride spectrum. 
Aluminic Chloride, Al 2 Cl 6 . — Aluminium has but two long lines, which fall between 
H 1 and IT,, and are of the following wave-lengths, 3961'0 and 3943-0 ; these alone are 
visible in the spectrum of aluminic chloride. 
It will be seen from the foregoing that in the case of elements with low atomic 
weights, combined with one equivalent of chlorine, the number of lines which remain in 
the chloride is large — over 60 per cent., for instance, in the case of Li, and 40 per cent, 
in that of Na. While, on the other hand, in the case of elements with greater atomic 
weights, combined with two equivalents of chlorine, we get a much smaller number of 
lines remaining — 8 per cent., for instance, in the case of Ba, and 3 per cent, in the case 
of Pb. 
Preliminary Experiments with Mechanical Mixtures. 
Another series of experiments has had for its object the examination of the spectrum 
of mechanically mixed metals — alloys prepared ad hoc. These experiments, which 
