THEORY AND PRACTICE. 79 



a base for the free acids exposed in the freshly-moved 

 subsoil. 



I had taken some pains to ascertain the previous 

 character of the field. Fifteen or sixteen bushels of 

 wheat to the acre (undrained, in ridge and furrow) 

 was the utmost crop the memory of man could 

 furnish an account of. 



The crop of wheat came up well, looked even and 

 healthy, but not thick, throughout the succeeding 

 summer, and ripened late. The produce, Avhen 

 threshed out, was six-and-thirty bushels, including 

 rather more than half a bushel of ' Tail,' to the 

 acre. 



How completely the Lime had done its work, 

 in both capacities, may be judged of from the 

 fact that on a couple of acres which I retained 

 expressly for the after experiment, and sowed with 

 Beans and then with Oats, unmanured, the two 

 succeeding years, the return exhibited an utter 

 exhaustion of the productive powers of the soil, to 

 an extent that I could hardly have believed, without 

 experimental proof. 



Though it cannot be desirable to see the practice 

 of bare fallows extended ; for it exists already upon 

 many soils where it might be with every advantage 



