180 MASSACHUSETTS AGRICULTURE. 



1. It retains more moisture than is needful for the plant. 



2. It attracts and holds the nutriment, and does not impart 

 it sufficiently for the proper nourishment of vegetation. 



3. It renders the soil hard, and difficult to cultivate. 



4. It resists the proper extension of the roots. 



5. It prevents the proper effects of the air and the heat. 



6. In dry weather, it cracks and admits the air directly upon 

 the roots, which is always injurious. 



If the sand is in excess, its injurious effects are : — 



1. It has but little adhesion to the nutritive matter, which 

 is quickly washed out, or is supplied too freely to the plant, 

 consequently the soil is quickly exhausted. 



2. It does not sufficiently retain the moisture for the plants. 



3. It does not attract fertilizing particles from the atmos- 

 phere. 



4. Being a good conductor of caloric, it transmits to the 

 roots immediately the influences of sudden changes in the 

 temperature of the atmosphere. 



These facts show the great importance of ameliorating clay 

 land with sand, and sandy land with clay. In many parts of 

 England this has been done with most successful results, and 

 there is no reason why our farmers may not by this method 

 greatly benefit their poorer lands, as in most instances beds of 

 clay may be found in the vicinity of sandy lands, and sand in 

 the vicinity of clay lands. Probably nothing that can be done 

 to such lands will be more permanently beneficial. 



Besides the clay and sand, the composites of soil are mineral 

 substances and vegetable mould, in the quantities before stated. 

 These afford the nutriment to the plant. The term vegetable 

 mould or humus, has been used by some writers with a more 

 extensive signification than that in which I propose to employ 

 it in this report. 



It has been used to define the entire organic and inorganic, 

 or mineral substances of a plant, in a certain state of decom- 

 position and solution. It is a dark, and when moist, an unc. 

 tuous mould, produced not only by the corruption and decay of 

 the falling leaves, the plants themselves, and the roots remaining 

 in the ground, but also by the putrefaction and decomposition of 

 animal matter, although the latter contains the ingredients of 

 the former in different proportions and is especially rich in 



