ON THE CHEMICAL CONSTITUENTS OF SOILS. 211 



to all plants ; or when a selection has been made, it 

 "was not based upon a knowledge of their peculiar 

 characters or composition. 



The cost of labor in England has given rise to 

 the production of much ingenuity in the invention 

 of machines, which have produced improvements in 

 the mode of application of manures. In order to 

 use these with advantage, pulverulent manures are 

 employed, instead of the common stable manure, 

 which is generally mixed with much straw. 



The necessity for such forms of manure naturally 

 suggested the employment of bone dust, dried dung, 

 lime, ashes, &c. Now, although by these means the 

 necessary phosphates are furnished to a soil, and 

 solid animal excrements rendered unnecessary, they 

 have led to the neglect of the liquid excrements, 

 that is, of the urine of men and animals, which is 

 thus completely lost to agriculture. For although 

 the meadows receive, during autumn and winter, 

 when cattle are fed upon them, the solid and liquid 

 excrements of these animals, yet the urine of man, 

 into which all the nitrogenous constituents of ani- 

 mals are finally deposited, is completely lost to the 

 fields. This most important of all manures, so pro- 

 perly estimated in Flanders, Germany, and China, is 

 altogether lost to the English agriculturist. In large 

 towns it is either allowed to run into the rivers, or 

 sink into the ground in such a manner as to be of no 

 benefit to the vegetable kingdom. 



The most important growth in England is that of 

 wheat ; then of barley, oats, beans, and turnips. Po- 

 tatoes are only cultivated to a great extent in certain 

 localities ; rye, beet-root, and rape-seed, not very 

 generally. Lucern is only known in a few districts, 

 whilst red clover is found universally. Now, the se- 

 lection of inorganic manures for these plants may be 

 fixed upon by an examination of the composition of 

 their ashes. Thus wheat must be cultivated in a soil 

 rich in silicate of potash. If this soil is formed from 

 feldspar, mica, basalt, clinkstone, or indeed of any 



