December, ig20 



PROCEEDINGS 



ROYAL IRISH ACADEAIY 



Volume XXX V, Skc iion A, No. 4 



J. J. NOLAN 



THE NATURE OF THE IONS PRODUCED 

 IN AIR BY RADIO-ACTIVE BODIES 



DUBIJN 



HODGES, FIGGIS, & CO. 



LONDON: WILLIAMS & NOKGATE 



1920 



Priee One S/iilliiig 



