17ti ON MANURE. 



phates in the ashes of firs and pines amounts to from 9 to 15 per 

 cent. : the ashes of the poplar contain 16 j per cent., and those 

 of the hazel-nut tree 12 per cent.* 



With every hundred pounds of lixiviated ashes of the beech, 

 we furnish to the soil as much phosphates as are contained in 

 460 lbs. of fresh human excrements. 



According to the analysis of Saussure, 100 parts of the ashes 

 of grains of wheat contain 32 parts soluble and 44*5 parts inso- 

 luble, or altogether 76-5 parts of soluble and insoluble phosphates. 

 The ashes of wheat-straw contain in all 11*5 per cent, of phos- 

 phates. Thus with every 100 lbs. of the ashes of beech, we 

 furnish to the field phosphoric acid sufficient for the production 

 of 4000 lbs. of straw (calculating its ashes at 4 per cent., accord- 

 ing to Saussure), or for 2000 lbs. of the grains of wheat (calcu-< 

 lating their ashes at 1*3 per cent. — Saussure). 



The dry fruit of the horse-chestnut (JEscidus hippocastonum) 

 yields 34 per cent, of ashes, possessing a similar composition to 

 the ashes of maize, and of the grain of certain kinds of wheat. f 



The importance of manuring with bones must be obvious to 

 all. The bones of man, and of animals in general, have their 

 origin from apatite (phosphate of lime), which is never absent 

 from fertile land. The bone earth passes from the soil into hay, 

 straw, and other kinds of food, which are afterwards consumed 

 by animals. Now, when we consider that bones contain 55 per 

 cent, of the phosphates of lime and magnesia (Berzelius), and if 

 we assume that hay contains the same quantity of these salts as 



* Ashes of pines from Norway contain the minimum of phosphates — 

 viz. # 9 per cent. — Berthier. 



f Ashes of the fruit of the horse-chestnut [Saussure]: 



Potash .------51 



Alkaline phosphate? - - - - 2S 



Chloride of potaarium v:.d sulphate of ) „ 

 potash - - - - 5 



Earthy phosphates - 12 



Silica 05 



Metallic oxides ----- 0*25 



Los* - - 5*25 



10000 



