or SOME OF THE CHEMICAL ELEMENTS. 
149 
liant red purple. The contrast is exceedingly beautiful between this and the intense 
green light of thallium. Two or three nebulous bands in the red present indications of 
resolvability. There is also a diffused green light from 1297 to 1375. The line 1506 is 
in a small degree more refrangible than the strong thallium line. The strong line 1260 
is very near a tin line, but the contrast between the sharp calcium line and the nebulous 
tin line is very marked. A pair of strong lines is seen near the extreme refrangible end 
of the spectrum, which may coincide with those of Fraunhofer’s H. This specimen of 
calcium produced also the lines of magnesium ; these were of course omitted, as on the 
chemical analysis of this specimen of calcium it was found to contain magnesium. 
13. Barium . — As I could not obtain barium in the metallic state, I prepared an 
amalgam of barium by the electrolysis of chloride of barium. The mercury was a 
portion of the same used in the other experiments, and which had been examined in 
the spectroscope. The spectrum is one of great beauty, and the lines are for the most 
part sharp, narrow, and intense. There is a very strong line in the indigo, near a line 
of platinum ; the latter is furnished also by my specimens of iridium and rhodium. 
The line next in greater refrangibility appears to agree very nearly in position with 
one of tin. 
14. Strontium . — Metallic strontium prepared by Dr. Matthiessen was employed. 
The spectrum is exceedingly brilliant, the lines being numerous, narrow, and intense. 
It is remarkable for several bright nebulous columns in the red and orange ; these pre- 
sent indications of containing numerous fine lines. 
This metallic strontium contains calcium, the lines of which have been eliminated. 
An amalgam of strontium was prepared, and with this all the principal lines of the 
spectrum from the metal were confirmed. As might be expected, many of the fainter 
lines were not recognized in the spectrum of the amalgam. 
15. Manganese . — The lines were obtained from an electro-deposit of manganese from 
a solution of the chloride of manganese. Upon comparing this with a specimen of 
manganese which I was informed had been reduced by charcoal, all the lines of the 
electro-deposited manganese were seen in the other ; but this contained, in addition, the 
numerous lines of the iron-spectrum. The most characteristic groups are a triple line 
from 909 to 915*5, the five lines from 2267 to 2401, and the close group extending 
from 3097 to 3133. 
There are two remarkable broad nebulous bands, one at 840 and the other at 1565 ; 
the former, I suspect, is double. As the deposited manganese is brittle, the lines were 
fitful in consequence of the disruption of portions of the deposit by the spark. This 
may be the reason that some of the finer lines were not observed. 
16. Thallium . — The specimen of thallium was lent me by Professor W. A. Miller, 
who received it as pure thallium from Mr. Crookes. With the exception of a few faint 
lines, one in the red rather strong, and a distinct line near the most refrangible end, the 
spectrum agreed with the description in Professor Miller’s “ Note ” on Thallium*. 
* Proceedings of the Royal Society, January 1863, vol. xii. p. 407. 
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