[Aprin 12, 1906.] 
THE 
SCIENTIFIC TRANSACTIONS 
OF THE 
MO win SOC TRY. 
VOLUME IX.—(SERIES IL) 
JOO, 
SECONDARY RADIATION FROM COMPOUNDS. 
BY 
J. A. McCLELLAND, M.A., 
Professor of Experimental Physics, University College, Dublin, 
AND 
F, E. HACKETT, M.A., B.Sc. 
DUBLIN: 
PUBLISHED BY THE ROYAL DUBLIN SOCIETY, 
LEINSTER HOUSE, DUBLIN. 
WILLIAMS AND NORGATE, 
14, HENRIETTA STREET, COVENT GARDEN, LONDON, W.C. 
PRINTED AT THE UNIVERSITY PRESS, BY PONSONBY AND GIBBS. 
1906. 
