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soils with respect to atmospheric moisture, and I 
have always found it greatest in the most fertile 
soils; so that it affords one method of judging of 
the productiveness of land. 
1000 parts of a celebrated soil from Ormistown, 
in East Lothian, which contained more than half 
its weight of finely divided matter, of which 11 
parts were carbonate of lime, and 9 parts vege- 
table matter, when dried at SIS®, gained in an 
hour by exposure to air saturated with moisture, 
at temperature 6S°, 18 grains. 
1000 parts of a very fertile soil from the banks 
of the river Parret, in . Somersetshire, under the 
same circumstances, gained 16 grains. 
1000 parts of a soil from Mersea, in Essex, 
worth 4 5 shillings an acre, gained 13 grains. 
1000 grains of a fine sand from Essex, worth S8 
shillings an acre, gained 11 grains. 
1000 of a coarse sand worth 15 shillings an acre, 
gained only 8 grains. 
1000 of the soil of Bagshot-heath gained only 
3 grains. 
Water, and the decomposing animal and veget- 
able matter existing in the soil, constitute the true 
nourishment of plants ; and as the earthy parts 
of the soil are useful in retaining water, so as to 
supply it in the proper proportions to the roots of 
the vegetables, so they are likewise efficacious 
in producing the proper distribution of the animal 
or vegetable matter : when equally mixed with it 
they prevent it from decomposing too rapidly ; 
and by their means the soluble parts are supplied 
in proper proportions. 
