_Clay._--The finest of rock particles, 1/5000 to 1/250000 of an inch
in diameter, too small to imagine. Clay when wet is very soft,
slippery and very sticky. Yellow ochre and whiting from the paint shop
are good illustrations of clay.

_Humus_, or decaying vegetable and animal matter. This is dark brown
or almost black in color--decaying leaves and woods soil are examples.

Soils composed of the above materials:

_Sands or Sandy Soils._--These soils are mixtures of the different
grades of sand and small amounts of silt, clay and organic matter.
They are light, loose and easy to work. They produce early crops, and
are particularly adapted to early truck, fruit and bright tobacco, but
are too light for general farm crops. To this class belongs the
so-called Norfolk Sand. This is a coarse to medium, yellow or brown
sand averaging about five-sixths sand and one-sixth silt and clay and
is a typical early truck soil found all along the eastern coast of the
United States.

"It is a mealy, porous, warm sand, well drained and easily cultivated.
In regions where trucking forms an important part of agriculture, this
soil is sought out as best adapted to the production of watermelons,
canteloupes, sweet potatoes, early Irish potatoes, strawberries, early
tomatoes, early peas, peppers, egg plant, rhubarb and even cabbage and
cauliflower, though the latter crops produce better yields on a
heavier soil."

A very similar sand in the central part of the country is called Miami