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carrots, clovers, then the manures which contain carbon, 
oxygen, hydrogen, as elements, as fermented straw, rape 
dust, &c. are to be used. If, as in wheat, barley, and oats, 
albumen and gluten abound, then the animal manures, as 
bones, urinous liquors, &c., in which nitrogen is contained, 
must be applied. The inorganic ingredients must also be 
studied ; for example, potatoes and the grasses contain much 
potash ; and cow dung, which contains a large proportion of 
that salt, must be used. The earthy ingredients of plants 
require particular attention ; the phosphates and silicates of 
potash abound in the cerealia; these substances must be 
supplied from either cow or horse dung, or from bones. But 
there is a great waste in the application of bones as respects 
their earthy constituents ; forty pounds of bones per acre is 
sufficient, says Liebig, to supply with phosphates, &c. three 
crops of wheat, clover, turnipsji^ &c. if properly applied, by 
being first mixed with half their weight of sulphuric acid, 
diluted with four parts of water, to which 100 parts of water 
are afterwards to be added, to be sprinkled on the land 
before ploughing. 
But the two former principles of keeping stock and col- 
lecting manures, have been acted upon by the Flemish farmer 
for centuries past, and they are now being adopted through 
some parts of France, through Switzerland, Germany, and 
parts of Italy. The Flemish farmer collects with the greatest 
assiduity all kinds of manures ; for the collection of liquid 
he provides large tanks; by a judicious succession of crops 
he has every part of his land in a constant state of produc- 
tion ; yet with a soil inferior to the limestone, and only to be 
compared to the poor light soils of Norfolk, and with a cli- 
mate in which the frosts are longer and more severe than in 
England, the agriculture of Flanders maintains a population 
of ten souls on every sixteen acres, and exports one-third of 
the produce of the whole country annually, while England, 
