182 OF MANURE. 



abundance those contents of the soil which are 

 essential to their growth and development. 



From the foregoing remarks it will readily be in- 

 ferred, that for animal excrements, other subtances 

 containing their essential constituents may be sub- 

 stituted. In Flanders, the yearly loss of the necessary 

 matters in the soil is completely restored by covering 

 the fields with ashes of wood or bones, which may 

 or may not have been lixiviated * and of which the 

 greatest part consists of the phosphates of lime and 

 magnesia. The great importance of manuring with 

 ashes has been long recognised by agriculturists as 

 the result of experience. So great a value, indeed, 

 is attached to this material in the vicinity of Mar- 

 burg and in the Wetterau,f that it is transported as 

 a manure from the distance of 18 or 24 miles. J Its 

 use will be at once perceived, when it is considered 

 that the ashes, after having been washed with water, 

 contain silicate of potash exactly in the same pro- 

 portion as in straw (10 Si 3 -|- K 0.), and that 

 their only other constituents are salts of phosphoric 

 acid. 



But ashes obtained from various kinds of trees are 

 of very unequal value for this purpose; those from 

 oak-wood are the least, and those from beech the 

 most serviceable. The ashes of oak-wood contain 

 only traces of phosphates, those of beech the fifth 

 part of their weight, and those of the pine and fir 

 from 9 to 15 per cent. The ashes of pines from 

 Norway contain an exceedingly small quanfity of 

 phosphates, namely, only 1*8 per cent, of phosphoric 

 acid. (Berthier.) \ 



* Lixiviation signifies the removal by water of the soluble alkaline or 

 saline matters in any earthy mixture ; as from that of lime and potash, 

 or from ashes to obtain a ley. 



t Two well known agricultural districts; the first in Hesse-Cassel, 

 the second in Hesse-Darmstadt. — Trans. 



t Ashes are used with great advantage on the light siliceous soil of 

 Long Island, Connecticut, and various other places in the United 

 States. 



^ " The existence of phosphate of lime in the forest soils of the United 

 States, is proved not only by its existence in the pollen of the pinus 



