





THREE NEW EDITIONS IN THE 



Progres sive Science Series. 



VOLCANOES: Their Structure and Significance. 



By T. G. BONNEY, D.Sc, F.R.S., Emeritus Professor of Geology at University 

 College, London. Third (New and Enlarged) Edition. With numerous 

 Illustrations. Demy 8vo. 6s. net. 



This edition has been enlarged by succinct accounts of some interesting 



volcanic eruptions which have occurred during the present century. The text 



generally has been revised and considerable alterations have been made in 



chapter dealing with the causes, of which eruptions, and their more con- 



ious phenomena, are probably the consequences. 



THE INTERPRETATION OF RADIUM. 



By FREDERICK SODDY. M.A., Independent Lecturer in Physical Chemistry 

 and Radioactivity in the University of Glasgow. Third Edition. Revised 

 and Enlarged. With Illustrations. Demy 8vo. 6s. net. 



This gives in popular language an account of radium and describes how its 

 unique properties have been interpreted on the new theory of the disintegra- 

 tion of its atoms, which invades so many departments of thought. The new 

 edition has been thoroughly revised and enlarged to include an account of 



other radioactive elements of the thorium and actinium series, of which -v 

 some, like mesothorium and radiothorium, have a considerable and growing ) 

 importance as effective substitutes for radium, itself becoming ever more 

 ossible to obtain. 



HEREDITY. 



By J. ARTHUR THOMSON, M.A., Regius Professor of Natural History in 

 the University of Aberdeen. New and Thoroughly Revised Edition. With 

 numerous Illustrations. Demy 8vo. gs. net. 



1TURE. — w books of science which we ought to read 



h pleasure, but to which we turn with shrinking. Full, perhaps, of new 



facts and ideas, they are so expressed as to bore consumedly. 'Heredity' 



mother category. He who runs may read, even if he be a 



and he who reads will probably not cease to run until he has 



the last page." 



E PROGRESS.— "This is certainly the best modern bool 

 on ! mend to the student and the intelligently curious." 



JOHN MURRAY, ALBEMARLE STREET, W. 



( xviii ) 



