PREFACE ix 



Prof. A. Muntz, the late Prof. J. P. Cooke, LL.D., 

 and many other scientific workers. 



In conclusion, the author wishes to place on 

 record the great help he has received from 

 Mr. J. Scurlock, Mr. E. H. Wilson, the late Mr. 

 Cecil Massey, Ph.C, and others in the analyses of 

 plant ashes, soils, etc. 



A. B. GRIFFITHS. 



" Ivanhoe," Stock well Paxk Road, 

 Lonclon, S.W. 

 October, 1907. 



