[Fuprvary, 1882. ] 
THE 
SCIENTIFIC -TRANSACTIONS 
OF THE 
nO Ads DUBLIN SOCIHTY. 
VOLUME I. (SERIES IL.) 
XV1.—Photographs of the Spark Spectra of Twenty-one Elementary Substances. By 
W. A. Harruny, F.RS.E., Professor of Chemistry, Royal College of Science, 
Dublin.—Puares XVI., XVII. anp XVIII. 
DUBLIN: 
PUBLISHED BY THE ROYAL DUBLIN SOCIETY. 
PRINTED BY ALEX. THOM & CO,, 87, 88, & 89, ABBEY-STRERET, 
THE QUEEN'S PRINTING OFFICE. _ 
FOR HER MAJESTY’S STATIONERY OFFICE, 
1882. 
