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XI. 
PHOTOGRAPHS OF SPARK SPECTRA FROM THE LARGE ROWLAND 
SPECTROMETER IN THE ROYAL UNIVERSITY OF IRELAND. 
PART I. THE ULTRA-VIOLET SPARK SPECTRA OF IRON, COBALT, 
NICKEL, RUTHENIUM, RHODIUM, PALLADIUM, OSMIUM, IRIDIUM, 
PLATINUM, POTASSIUM CHROMATE, POTASSIUM PERMANGANATE, 
AND GOLD. By W. BH. ADENEY, D.Se., A.R.C.Se.I., Curator and Examiner 
in Chemistry in the Royal University of Ireland, Dublin. 
(Prates XX VII. and XXVIII.) 
[Read Aprim 17, 1901. ] 
Introduction. 
Prcuiarities in the constitution of spark spectra of the elements were first 
described in the Scientific Transactions of this Society.* 
The photographs were taken with the first spectrograph constructed, which 
admitted of the whole of the spectra being included on one plate and extending 
from waye-lengths 4700 to 2000. The method of photographing, and the con- 
struction of the instrument, were described in a paper published by this 
Society. f 
In “Notes on certain Photographs of the Ultra-Violet Spectra of Elementary 
Bodies,” t it was shown that when the elements were classified along with their 
spectra in well-defined groups, according to the periodic law, there were marked 
characteristics which were shown to belong to distinctive groups of the elements. 
These peculiar characteristics of the lines were length and continuity from pole to 
pole, with emissive power of intensity of chemical action, extension above and 
below the points of the electrodes, the nimbus or aureole, sharpness or diffuseness, 
and the background of continuous rays. The features of the lines were correlated 
with the chemical and physical properties of the elements, such as conductivity, 
* Hartley, vol.i., p. 281, 1881. 
} Sci. Proc. Roy. Dublin Soe., vol. iii., ser. 2, p. 98, 1881 (Hartley). 
{ Journ. Chem. Soc., vol. xliii., p. 384, 1882 (Hartley), and ‘“‘On Homologous Spectra” (Joc. cvt., vol. 
xhii., p. 890, 1883, by the same author). 
TRANS. ROY. DUB, SOC., N.S., VOL. VII., PART XI, 3A 
