BY J. C. BRUNNICH, F.I.C. 43 



The foundation of all agriculture is unquestionably 

 the Soil, a layer of more or less weathered, crumbled rock, 

 which covers the surface of Mother Earth, and is absolutely 

 necessary to support any growtli of plants. Only by the 

 aid of the mineral matters obtained from tlie soil are plants 

 able to grow and avssimilate the organic plantfoods existing 

 as an inexhaustable supply in the ocean of air. The con- 

 stitution of the soil is very intricate and ever clianging, 

 and both the mineral ingredients, and the organic sub 

 stances, HumuS, formed by the decay of vegetable matter, 

 together with the host of micro-organisms living in the soil, 

 are of vital importance. 



The importance of bacterial life has only of late years 

 been properly recognised, and when we are told that one 

 grain of soil may contain millions of micro-organisms, one 

 cannot wonder at their far-reaching influence on the fertility 

 of a soil. 



The skeleton of the soil is formed by mineral matters, 

 at)d Geology is the science which will teach the agriculturalist 

 the influence and importance of certain rocks on the ctvji- 

 position of soils. Geological maps of countries, illustrating 

 the underlying strata, are of immense value to the scientific 

 farmer, particularly those known as drift maps, which show 

 the mineral matters actually existing on the surface. In 

 some countries accurate soil maps are now available, which 

 indicate the class of soil in each locality. These can only 

 be produced by an exhaustive special examination. The 

 United States Bureau of Agriculture has undertaken such 

 a complete soil survey, a truly gigantic undertaking which 

 will employ a large staff of experts for years. 



But for the study of the soil, other factors besides 

 geology have to be taken into consideration ; they are its 

 chemistry, physics, and, as already indicated, its biology, 

 all which go hand in hand for the elucidation of tlie 

 character of a soil. For years the fertility of a soil was 

 chiefly judged by its chemical composition, paying, of 

 course, due regard to the mechanical and physical con- 

 dition, but of recent years the American school, as repre- 

 sented by M. Whitney and F. K. Cameron, declare that the 

 chemical composition of a soil has little to do with or to, 

 tell about the fertility of a soil, and that manures, if they 



