114 WOOD ASHES. 



when these two gases are liberated in contact, 

 as in the decay of animal and vegetable mat- 

 ter, where it is always present ; the nitrogen 

 being set free by the decomposition of the 

 matter itself, and the hydrogen being evolved 

 from the decomposition of water, which is 

 always and under all circumstances necessary 

 to produce the ultimate decay of matter. 



Its price as an article of commerce will, it is 

 feared, always prevent its use in a manufac- 

 tured state, and indeed, if we only reflect on 

 the immense quantities of this manure which 

 are now wasted, and which might and ought 

 to be saved, we shall be convinced that we 

 never need apply to the manufactured article 

 for a due supply of this important matter. 



Ashes — Wood. — The benefit arising from the 

 use of wood-ashes arises entirely from the pot- 

 ash they contain, which being dissolved by the 

 first rain that falls after they are appUed, dis- 

 solves the salt and carries it into the earth, 

 there to be absorbed and assimilated as pre- 

 viously described. 



Some kinds of wood (and in wood we should 

 include all plants) yield in their lixiviation a 

 much larger quantity of this salt than others, — 

 thus the ashes of dried wormwood contain 30 per 

 cent, of this salt, and are consequently very bene- 

 ficial. The ashes of nettles, and generally the 

 ashes of all plants which flourish on rubbish 

 heaps, the ruins of old buildings, and in hedge 

 rows are rich in these salts, as their luxuriant 

 growth testifies to the abundant presence of the 

 potash in the soil where they exist, and it would 

 amply repay the agriculturist to collect such ve- 



