l8 '.,: TOE, /FERTILITY OF THE SOIL 



growth of the plant. All that science can do as yet is to 

 ascertain the existence of these factors, one by one, and 

 bring them successively under control, but though we 

 have been able to increase production in various direc- 

 tions, we are still far from being able to disentangle all 

 the interacting forces, whose resultant is represented by 

 the crop. 



One other point I trust my sketch may have suggested 

 to you. When science, a child of barely a century's 

 growth, comes to deal with a fundamental art like 

 agriculture, which dates back to the dawn of the race, it 

 should begin humbly by accepting, and trying to inter- 

 pret, tradition. It is unsafe for science to be dogmatic ; 

 the principles upon which it relies for its conclusions 

 are often no more than first approximations to the truth, 

 and the want of parallelism, which can be neglected in 

 the laboratory, gives rise to wide divergencies when 

 produced into the regions of practice. The method of 

 science is after all only an extension of experience; 

 what I have endeavoured to show in my discourse is 

 that the traditional practices of agriculture and the most 

 modern developments of science are linked by a con- 

 tinuous thread. 



