150 
ME. W. HUGGINS ON THE SPECTEA 
17. Silver. — The spectrum is that of electrotype silver, obtained from pure nitrate of 
silver in cyanide of potassium. 
18. Tellurium. — This metal was supplied to me as pure by Messrs. Johnson and 
Matthey. It contains many strong and characteristic lines. The strong line in the red 
is very near the strong line in cadmium, but the latter is in a small degree less refran- 
gible. 
19. Tin. — The spectrum was obtained from purified tin, and confirmed by compa- 
rison with electrotype tin ; one line, not observed in the spectrum of the latter, has 
been omitted. 
20. Iron. — Electrotype iron was employed. This spectrum agreed exactly with a 
specimen received from Dr. Matthiessen as very nearly, if not quite, pure iron. 
21. Cadmium. — The spectrum of purified cadmium was confirmed by comparison with 
cadmium electro-deposited. 
22. Antimony. — The numerous and strong lines of this spectrum are, for the most 
part, nebulous at their boundaries. The spectrum is that of electro-deposited antimony. 
23. Gold. — The specimen of which the spectrum is given was received from Pro- 
fessor Miller. It was reduced by him from the pure chloride, and fused under bisul- 
phate of potash. 
24. Bismuth. — Electro-deposited from the nitrate of bismuth. 
25. Mercury. — Commercially pure mercury was washed with nitric acid, and then 
distilled. A portion of this was placed in a small cup made from glass tube, into which 
a platinum wire was sealed. The other electrode was a platinum wire. 
26. Cobalt. — Electrotype cobalt from the chloride was employed. The lines are 
numerous, sharp, and narrow, and in their groupings there is considerable resemblance 
to the spectrum of iron. 
27. Arsenic. — From a specimen of carefully re-sublimed arsenic received from Pro- 
fessor Miller. The strong line 1814 is very near, but not quite so refrangible as, one 
of the strong lines of copper. The strong line in the red, 812, is near the hazy band of 
the air-spectrum. 
28. Lead. — The lead was obtained by electrolysis from the nitrate of lead. 
29. Zinc. — Electrotype zinc was used. This spectrum is remarkable for the strong 
contrast between the nebulous lines, and others near them sharply defined. 
30. Chromium. — The chromium was electro-deposited. The triple nebulous band 
from 1081 to 1090 is remarkable. The groups of lines in the blue and indigo, which 
for the most part fall between air lines, are very beautiful, and in a marked manner 
characteristic of this metal. 
31. Osmium. — Received as pure from Messrs. Johnson and Matthey. Iridium and 
rhodium have also been measured, but, as these have lines in common, their spectra are 
deferred. 
32. Palladium. — A specimen prepared by Dr. Wollaston was observed simulta- 
neously with palladium received as pure from Messrs. Johnson and Matthey. The 
