EARTH 

 SCIENCES 



UBRARY 



DEDICATED 

 TO 



JOHN ADDINGTON SYMONDS, M.D. 



F.R.S.E. M.RC.PH., 



OF CLIFTON HILL HOUSE, BRISTOL, 



TO WHOSE SKILL AS A PHYSICIAN, 



AND 

 TO WHOSE UNWEAEIED KINDNESS AS A FEIEND, 



THE WRITER 



GRATEFULLY ACKNOWLEDGES 



HIS DEEP AND LASTING 



OBLIGATION. 





