160 APPENDIX. 



Magnesia, ..... 8.70 



Oxide iron, ...... 22.30 



Oxide manganese, ..... 5.50 



Lime, ....... 27.20 



100. 



Wheat straw, — 100 parts yield .044 of ashes ; 100 parts of which af- 

 ford, — soluble, 19; insoluble, 81. 



100 parts af the soluble contain: 



Sulphuric acid, ...... 0.2 



Muriatic acid, ...... 13. 



Silex, 35.6 



Potash and soda, ..... 50. 



100 parts of the insoluble contain: 



Phosphoric acid, 

 Silex, . 

 Oxide iron. 

 Lime, . 

 Charcoal, 



Peat-ashes abounds in carbonate, sulphate, and especially phosphate 

 of lime. I have always tracedy/'ce alkali in peat ashes ; but alkali ex- 

 ists in it, rather as silicate, as in leeched ashes. Anthracite coal ashes con- 

 tain a carbonate of lime, alumina, and oxide of iron. It is good, so far 

 as these abound. 



The above are calculated on the analysis of Berthier, who has detected 

 soda in the ashes of ail plants. The elements are stated singly ; be- 

 cause we have thus at one view the amount of each, and, as I shall 

 show, it 13 the base chiefly which acts. The agricultural value of ashes 

 may be determined by reference to these tables. In what state these 

 elements may be combined in plants, we can only determine theoreti- 

 cally. Thus, the phosphoric acid, by its affinities, would be united in 

 the hard woods as above, with the lime and iron, — forming in each 100 

 parts of tiie insoluble portion of ashes, phosphate lime, 5.40 ; phosphite 

 iron, 1.86. 



Of the various substances which chemistry detects in the ashes, iew 

 probably exist in the living plant, in that state of combination, in which 



