TO 



SIR JOHN BEMET LAWES, BAKT,, D.C.L, LL.D., F.B.S., 



OF ROTHAMSTED, 

 AND 



SIR J. HENRY GILBERT, M.A., LL.D., F.R.S., 



FORMERLY SIBTHORPIAN PROFESSOR OP RURAL ECONOMY, 

 UNIVERSITY OF OXFORD, 



WHOSE FAMOUS INVESTIGATIONS DURING THE LAST FIFTY YEARS 



HAVE SO LARGELY CONTRIBUTED TO BUILD UP 



THE SCIENCE OF MANURING, 



THIS WORK, 



EMBODYING MANY OF THE ROTHAMSTED RESULTS, 

 IS DEDICATED. 



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