INVESTIGATIONS ON THE PRODUCTION OF PLANT FOOD. 187 



More recently it has been found that the useful organisms are on 

 the whole more resistant to adverse conditions than the useless or 

 harmful ones, and therefore that any process of gentle killing or partial 

 sterilization will effect an improvement. Experience is bearing this 

 out, but it is also demonstrating that the process cannot be carried 

 out without considerable trouble. " Truly," says Virgil, " the 

 farmer's path is not an easy one " ; and in that still older Book the 

 cultivator was told " in the sweat of thy face shalt thou eat bread." 

 So far I cannot see that modern science promises any short and easy 

 way of getting round this old injunction. What it has done is to 

 dignify the husbandman's calling by revealing something of the 

 wonder and beauty of the factors involved ; it has shown also how his 

 labour may be better directed as his knowledge of the forces of 

 Nature becomes more and more extended. 



