84 OUR FARM CROPS. 



fore, from one part alone might be widely different from 

 the soil of the other parts of the field, while a number of 

 samples drawn from these differing soils and mixed to- 

 gether, might still more mislead, and represent no portion 

 of the surface-soil whatever. Again, take the same soil 

 under different conditions: take a sample in the early 

 spring, after the rains of winter have acted upon the sur- 

 face, and carried its more soluble constituents down into 

 the subsoil, or away altogether in the drainage ; and take 

 a sample from the same spot at the close of autumn, when 

 no rain has passed through the soil for months, but has 

 passed off by evaporation, leaving behind in the surface- 

 soil the soluble salts it had met with in its upward pas- 

 sage submit these two samples to the laboratory tests, 

 and see what different indications of fertility they would 

 give you of the same soil. The spring analysis would 

 indicate a soil poor in available food for the crop, while 

 that of autumn would place the same soil very high in the 

 scale of fertility. Even if the analyses of soils had fur- 

 nished us with all the reliable data we expected, we 

 should have failed to apply them profitably, until we were 

 equally acquainted with the composition .and constituents 

 of the plants we wished to cultivate, so that we might 

 know whether those ingredients which the plant required 

 for its growth, were to be met with in the soil in which 

 it was to be placed. The importance to be attached to a 

 chemical investigation into the composition of our farm 

 plants was at once recognized, and the subject was taken 

 up with great energy and liberality by the Royal Agri- 

 cultural Society, whose Journal promptly made known 

 to the agricultural community, abroad as well as at home, 

 the valuable and very interesting results obtained. In 

 the investigations carried out under their auspices, most 

 of our crops are comprised; those specially relating to 

 wheat will be found chiefly in Vol. vii. These investiga- 



