NArURE SERIES. 



POPULAR LECTURES 



AND 



ADDRESSES 



BY 



SIR WILLIAM THOMSON, LL.D.. F.R.S., F.R.S.E., &c. 



PROFESSOR OF NATURAL PHILOSOPHY IN THE UNIVERSITY OK GLASGOW, AM) 

 FELLOW OF ST. PEThK's COLLEGE, CAMBRIDGE. 



IN THREE VOLUMES 

 VOL. I. 



CONSTITUTION OF MATTER 



WI 7 77 7Z L US TRA TIONS 



ITmtbcm : 

 MACMILLAN AND CO. 



AND NEW YORK 

 1889 



