CHAPTEE X. 



WOOD-ASH. 



The amount of the food of plants in it Box-wood ash gives only the half of its 

 potash readily to water- Convenience in mixing Wood -ash with earth- before 

 applying it Lixiviated ash, its value Proper mode of applying ashes as a 

 manure. 



TT has already been stated that the proportion of pot- 

 J- ash is very dissimilar in different wood-ashes ; those 

 from hard wood being generally richer in that sub- 

 stance than those from soft wood. The ash of beech- 

 wood gives up to water the one-half of the potash in it, 

 in the form of carbonate of potash, the other half remain- 

 ing in combination with carbonate of lime, in a com- 

 pound which is only very slowly decomposed by cold 

 water. The ash of pine-wood generally contains, like 

 tobacco-ash, a larger proportion of lime, so that cold 

 water often seems to fail altogether in dissolving any 

 carbonate of potash out of it. However, the continued 

 action of water succeeds always in gradually extracting 

 from all these ashes the whole of the potash ; and since 

 they can be easily ploughed deeply in, they are suited 

 better than all other potash compounds to enrich with 

 that alkali the deeper layers of the arable soil. With 

 wood-ashes that part readily with their potash to water, 

 it will be found useful to mix the ash, before applying 

 it, with an earth that absorbs potash, adding so much 

 of the latter that water poured upon the mixture will 

 no longer turn reddened litmus-paper blue. This oper- 

 ation of mixing can best be performed on the field itself. 

 Wood-ash which has been extracted with water, 



